Unofficial Royal Enfield Community Forum

Royal Enfield Motorcycles => Bullet Electra & AVL => Topic started by: ringoism on March 30, 2018, 04:01:37 pm

Title: First AVL ownership/build... tech questions...
Post by: ringoism on March 30, 2018, 04:01:37 pm
Hi folks, figured it was time I finally join this forum, which I’d originally come across quite some time ago… reason being that I’m finally the owner of a 500AVL (“Machismo” in Indian parlance).  I'll try and keep future posts shorter...

Been quite interesting / enlightening reading through so many of the related threads – BW/Basanti/Tooseevee/DanB/Ace and many other long-term tinkerers / contributors.  Basic personal objective is just to have the thing a little more punchy and stronger all-round, especially in the midrange, without spending a lot of time/money or killing the low-end.   

I’m an American living over a decade and a half over here in S. Asia… never was much of a Bullet fan (have ridden many of all types), but have had some good experiences on them, and there’s something special about the 500AVL’s in my view.  Very much the traditional British single with a good bit of useful upgrading over the old iron units.  Having ridden the CI/AVL/UCE 500's side-by-side, all have their strong/weak points but somehow it seems the best compromise. 

My particular bike is a little unlike what most of you would have started out with… in that it has spent its whole life in the Himalayas, and is fairly well-worn, till recently a workhorse for a motorcycle tour company commonly doing the Manali-Leh Highway and other stunning routes in the region.  Early 2010 model, so one of he last produced here.  The engine as received started easily (often first kick even at freezing temps), ran fairly well and had good compression but was a bit noisy (internally) as is typical of used AVL’s here.  Under load, probably most of it was piston slap on account of its having around .008” clearance there, but there was 1mm side-to-side in the rod too, and senior mechanic here (who has been working years on this fleet of over 30 bikes for a decade now) felt that was contributing some rattle as well.  It had been rebuilt earlier, I was to discover.  God alone knows how many miles it has covered, how much abuse it has survived.  Besides the engine, the gearbox seemed to too often jump out of 2nd/3rd after initially engaging, clutch slipped a bit, etc, so figured it was time to just refresh the whole thing, and hopefully improve it a bit in the process.  Not a lot of time to go into great detail and many here have done it earlier and better, so initially will just be seeking advice / info here.

I bought a new cylinder kit to keep aside as a spare (under $125 here, and most domestic AVL parts supplies drying up, probably because of the demand for them from the U.S. / U.K.), but decided to do a 0.75mm (.030”) overbore instead.  Piston is a dished unit (1.5mm) from the UCE (AVL overbores not available) which with the near 85mm bore would’ve put compression down to 8.3:1, so decided to try BW’s shortened barrel/piston crown mod, especially as the low atmospheric pressures up here effectively lower your compression ratios and really sap the power (the thing runs SO much better 4,000ft down the mountain from here – we’re above 7,000).  So I’ve got a 64mm dia, 1mm raised section on the piston at 64mm dia., having cut the barrel and outer crown down by 2.5mm each.  My calculations put me at 9.1:1 with the raised section and added overbore volume.  Maybe a little more considering that the volume between the top ring and deck is now less as well.  Didn’t want to push it too much as I already did have some light detonation at low speeds on normal (87 octane?) fuel (a fair bit of carbon in there, and moreover Hitchcocks says they have found the Electra X’s advanced by over 7-degrees over factory spec, thus the offset woodruff keys, which I could probably make here).  Will have to see how the squish works out but both the barrel/case and head gaskets are pretty thick (nearly 2mm (.080”) thick fire-ring on the latter, .075” in the composite area, uninstalled) and if we’re aiming for .020-.060” squish (as per ACE), am thinking I may have to eliminate the barrel gasket in favor of RTV, or else cut a thinner one to fit there (I do have some gasket material available).  I doubt there are many options for head gaskets unless perhaps the UCE one would work - the AVL500 was a rare bird here (only 500 made the first year, supposedly limited thereafter as well, and only 3 years production).     

1.  One question would be re: any limitations as to how far the piston can sit above the deck, in the event I can’t find a thinner head gasket.  Stock gasket’s fire-ring is of course assuming an 84mm piston, so has an ID of 85mm which will decrease a little when compressed.  Which means I guess I’d have to bevel the top edge of the piston if it’s going above-deck?  Any issues with the top compression ring being a few mm’s closer to the deck than originally designed?  If my head gasket can compress down to .060 or so (not sure of this), I’d be right at the outer squish limit with the piston even with the deck, and more ideally I’d have to have it sticking out .020 or so.

Otherwise, would lapping the head/barrel and using a thin copper gasket be an option?  My 2-stroke Kawasaki uses one of these pretty fine. 

2.  Would it be highly advisable to change to the CI followers/guides while I’ve got the cases apart? I’ve heard of and seen the AVL tappets break here and mentioned in these forums.  What is involved, and how do we deal with the new pushrod lengths (someone said 3/8” shorter would be required?), without having to order expensive bits from abroad?  Any reason the stock ones couldn’t be shortened, being that they’re aparently tubular aluminum (adjusters press-fit in the ends?)?

3.  Anyone done anything inside these gearboxes?  Head mechanic here says they never go bad, which sounds ridiculous, especially since mine obviously pops out of gear sometimes and others I’ve ridden never did.  I bought three new selector forks and a new indexing spring (will check the indexing plate/disc once apart), and hope to install both along with the refreshed engine.  Will see what the engagement dogs on the gear sides look like, on another bike I once resurfaced these with a die grinder to restore the 90-degree mesh surface.  Will check for loose shaft bearings, etc… Any other ideas?

4.  Re: the near-miraculous "S" cams... has anyone noted a drop in fuel efficiency after installation?  If it's mainly a change in lift it shouldn't be, but duration/overlap can start to cause negative effects in that realm.  I know that most in the U.S. / UK don't really think about that much (the stock bike gets something like 90mpg), but while I'd like a punchier, stronger pulling bike, I could care less about the "ton" and would probably kill myself trying it just about anyplace in the subcontinent.  And the fact that 90mpg is only about 25% less than I get from my 13.5hp, 150cc dual-sport makes it a little less difficult to justify owning this (third) motorcycle on what is a fairly slim budget...

I once made a set of high-lift cams myself using a precision grinder attachment on a lathe, reducing the base circle and just kind of blending it in to the existing lobe.  This was a ported, milled, relieved, self-built flathead 4hp Briggs and in finished form it would easily outrun an 8hp, so I guess I could say it worked.  But then, I only needed it to last through a six-hour enduro event in that case, and with AVL followers being fragile already... mmm... maybe not.  Basanti had said the stock iron cams were "way better" than the AVL's but never have seen specs on them or any other confirmations.  Anyone?  Other options?

Many Thanks,
Eric









Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on March 30, 2018, 04:53:37 pm
Oh, one more thing - any recommended, improved lubricants for engine/primary/gearbox?  We rarely see 85F up here in the hills, and I do a lot of short rides. 

1. The owner of this fleet of AVL's was of the opinion that tappets were less prone to failure with timely oil changes and quality (conventional) motor oil.  Not sure if I want to shell out for three liters of full-synthetic, but any of you have advice/views/experience on semi-synthetics / other grades?  (And do the tappets mainly break from merciless revving/neglect, or would even "normal" riders like myself be at risk?)

2.  Saw mention in the forum concerning the use of ATF in the clutch/primary drive.  I know Ford used it way back basically just to reduce drivetrain losses / improve MPG.  Any negative effects for the possible RE application?  I read the bit about using a liter in there vs. the factory-recommended half-liter, to save the high-mounted starter sprag.  Not sure if ATF could do that already challenged piece of hardware further harm. 

Same question for the gearbox.  Occasionally would do long uphill runs so the heat buildup could be there.  Any harm in using ATF?  Or even motor oil, since the UCE's are running their almost identical gear components in it?

Sorry for so many questions. 

To add a little info to the former post, I've got a 32mm Mikuni BS (CV) to replace the 28, found a manifold from a domestic Honda using that carb, ported the manifold (which oddly tapered down to maybe 25mm on the port side) to match the stock port.  But with the AVL port being "too large" (ACE), I wonder whether the taper-down could actually help "shoot" the charge into the port/chamber?  Should I have left it alone?  Why did Honda (CRF230 engine basically) do it in their application?  Going to ditch the toolbox-mounted air filter and figure out something less convoluted/freer-flowing.  Managed to remove the "hot tube" from the header pipe (royal pain).  Did a 3-angle valve job, cleaned up / matched the ports a bit - one very sharp edge on the floor of the exhaust port removed, in particular. 

Changing rear rim/tire to the C5 (120/80-18) setup (I hope it fits, a little tight tire-to-swingarm clearance), and the front to a fairly soft-compound (Ralco) 90/90-19 available here, down from the tallish hard-compound 3.25.  Hard rubber and cold / wet pavement don't get along too well and I ride in all sorts of weather, incl. snow on occasion. 

This is to be a low-budget, medium-impact, fun build and learning experience.  Tourist season brings horrible traffic jams up here and by car it takes hours to cover the four miles to town, so the bike is often the family vehicle.  Registered in my wife's name in fact, who wants to ride it by year's end (currently practicing on my Kawi KH125)...

Besides Briggs&Strattons have built some 2-stroke bikes and American V-8's in my time, but this is my first Enfield attempt, and while the basics are similar, it is a weird machine in some respects (couldn't believe the amount of work involved in changing out the front chain sprocket... and adjusting the steering head bearings will be interesting to be sure).       

Regards,
Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: REpozer on March 30, 2018, 06:31:02 pm
Welcome Eric,
Many good questions. I’ve never had my AVL engine apart or the 5 speed gear box. But mine is not used as yours was.

I have used all different kinds of lube in my Primary Drive. And I’ve always used a full Liter. Currently using ATF - F . It seems to work fine. I’ve also used 20w-50 motor oil, 10w-30 motor oil , 15w-40 motor and Diesel motor oil , and 50/50 motor oil and ATF, with no real noticeable difference.

The 5 speed gear box has always used 90w gear oil.

The engine , I’ve used 20w50 motor oil, and currently using 15w-40 diesel truck motor oil( for the ZDDP).

The  front shocks , I’ve tried 10w-30 motor oil( ride too hard) currently using ATF-F ( better ride).

As you can see , many off the shelves lube will work fine if you know what your doing ( sounds like you do)

Hope this answers a few questions. Others will jump in for more technical stuff.
Title: Re: First AVL ownership/build... tech questions...
Post by: tooseevee on March 30, 2018, 07:33:02 pm
Hi folks, figured it was time I finally join this forum, which I’d originally come across quite some time ago… reason being that I’m finally the owner of a 500AVL (“Machismo” in Indian parlance).  I'll try and keep future posts shorter...

Been quite interesting / enlightening reading through so many of the related threads – BW/Basanti/Tooseevee/DanB/Ace and many other long-term tinkerers / contributors.  Basic personal objective is just to have the thing a little more punchy and stronger all-round, especially in the midrange, without spending a lot of time/money or killing the low-end.   


              Welcome To The Monkey House.

               Wow - your bike has been rode hard and put away wet many times being a recovering Himalaya Basher. I've watched many many many of the Youtube Himalaya Lunatics video clips bashing their way up and down those unbelieveable roads. Mine's a pampered show girl princess compared to yours.

              Good luck and have fun.
Title: Re: First AVL ownership/build... tech questions...
Post by: DanB on March 30, 2018, 10:20:38 pm
Welcome Eric! 

Wow, you got a whole lot going on. I’ll take a stab at a couple of issues.

1. Base gasket. Don’t need one. Use good rtv and make sure to be generous around the pushrod tunnels. Go slow and let the stuff setup before final compression. (Had to do mine twice).

2. Head gasket. I used stock; it’s thick. Our hosts do sell an avl copper gasket at 1 mm thick. Not sure if that’s an option for you. You could have one made. W/o base and stock gasket, I was able to get barely into target squish range. 1 mm is the perfect target for me.

3. Piston to deck clearance. I don’t think you’ll have a problem. Mine protruded the deck plane by around .8 mm when all’s said and done. Used a stock piston for avl.

4. Check your valve clearances. Especially the inlet. Clay is good for this. I had to cut into piston.

5. Adrian is the man for replacing the stock tappers with IB versions. If you’re there, do it.

6. S cams or aces cams will really open things up. It’s the lift plus duration. I like the idea of grinding a set. Not for me personally.

7. Gear box. Before going to town on it, I’d work on the clutch adjuster. Open that little panel and try backing it off a sqoosh.

I’m sure ace will chime in on the carb setup. I’ve heard good things about the 32 cv carb. In terms of mileage.  No way do I get close to stock. Most likely it’s do to me being heavier on the throttle cuz it’s fun!

Oh yeah, stick with the 90 Wt gear box oil. Use whatever you have that’s slippery in the primary. If it is an electric start, use a liter.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on March 31, 2018, 12:14:08 am
Quote
5. Adrian is the man for replacing the stock tappets with IB versions. If you’re there, do it.


Er... I paid Bullet Whisperer to do it for my project bike engine!

Seriously, I would do this or have it done. My own Electra-X (the export version of the 500 AVL sold in the UK) snapped a cam follower foot of its stem, the foot then bounced around and bent the other follower. Other cam follower failures have also destroyed the timing gears. Ironically my project bike's engine started with another set of 500 AVL crankcases which had also had a broken cam follower. The fact is, the stem diameter was reduced too much in the AVL redesign, I can see the benefits of keeping the oil nice, but it can't make up for too little metal.

The AVL tappet/cam follower guides have a smaller outside diameter, so Iron Barrel guides will need turning down to match the AVL's, you may also have to sleeve them to preserve the correct fitting height. B.W. used a set of bronze guides from a Redditch (UK built) Bullet turned down to match, but with an alloy collar to set them at the right height when fitted. He took a few pictures.

With the wider stem followers you also loose the valve lifter collar. You will note that he also replaced (at my request) the adjustable cam spindles with solid spindles, something less to come undone.

The other thing you will have to do is play with different push rods, tappet adjusters and push rod tops. The push rods need to be about 3/8" or roughly 10mm longer if using Iron Barrel cams, Indian or Redditch "S".

The point of replacing the AVL cams with the "S" is that the originals have been found to cause valve bounce at 5,800 RPM, they can be used with the original tappets/followers, though, if you slacken off the tappet adjusters enough.

Also, watch inlet valve head to piston crown clearance with "S" or Indian iron barrel cams, particularly if you're timing the cams on the original timing dots. You can grind a pocket in the piston crown if you have to.

A.





Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on March 31, 2018, 06:27:02 am
Wow, thanks to all of you who responded - I was hopeful, but didn't expect this much help this quickly.  Great community here. 

I'll check into the tappets today... lathe available locally, so the conversion shouldn't be too tough... but kinda need to get on the lathe personally as the local hacks don't really work to thousandths!  Need to have a look at the pushrods and see what would be involved to shorten them, also check whether new ones are easily enough available that I can afford to experiment. 

I'd probably stick with the AVL cams for now since I'm looking more at midrange and going above 5,800 isn't highly important to me. 

But anyone know the lift figures of the "S" cams vs. stock AVL?  And anyone know the rocker-arm ratio?   

If I get adventurous later and try grinding a set of cams, I could take the stock cams or else larger-base-circle CI units, reduce the base circles to something closer to the AVL's, take up the difference with the pushrod adjusters, and voila, high-lift cams that have roughly stock duration for the sake of fuel economy, but more lift/flow to improve power across the full rpm range.  If I had the heavier CI tappets / guides I'd worry less about the self-styled cams being ground a little less than perfectly or whatever.  Worst that could happen is the followers might wear faster, I suppose... at any rate, the highest (spring) pressures would be on the upper parts of the lobes, which would remain untouched.  Assuming proper tappet clearance, base circles see no load at all, and first part of the ramps relatively less pressure/more surface area anyway.  Might rig up a degree wheel and actually try this... 

Bike's sitting apart in someone else's shop, so not wanting to delay things too much, but I've got a day or two here - head mechanic still stuck in Delhi trying to source various Enfield parts - The "two wheeler" market there (Karol Bagh) was closed for a couple days due to some protests / government sealing of unauthorized commercial properties... such is life...

Thanks again to all,
Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on March 31, 2018, 03:01:36 pm
AVL inlet cam is about.280" lobe lift. Rocker ratio is about 1.2. I say "about" because probably no 2 cams or rockers are the same.

Std Bullet cams and "S cams" are about. 312" lobe lift.

The AVL cams are the ones with the larger base circle.

If you want more low-mid rpm torque,  then advance the cams with the Hictchcock 3-way pinion. Also, do the compression increase and set the squish. Do the tappets and cam spindles as reliability mods. I would also get the Wossner 87mm flat top piston, and put that in.

Don't do iron barrel performance cams for low-mid power. They are for upper rpm power. Don't do a bigger carb for low-mid power. Make a longer header and longer inlet stack for low-mid rpm power.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on March 31, 2018, 11:47:56 pm
Eric,

your riding and atmospheric conditions will be different to what I have been used to in the UK at not much above sea level. However, for general blattability (is that a word? It is now...) my Electra-X needed three things:

1. A reasonably free-flowing exhaust. Lose the hot tube out of the stock header pipe and fit a less restrictive muffler unless your local police are clamping down, as seems to be happening elsewhere in India;

2. Depending on what carburettors are available where you are, get a decent 4 stroke performance carb. I have used 32, and 36mm Dell'Orto pumper carbs as well as a TM36-31 Mikuni flat slide pumper. A VM32 or 34 Mikuni once jetted correctly will work too, as will the TM32 flat slide.

3. I don't know about the 500 Machismo, but the Electra-X came with an 18T countershaft sprocket, overgeared for me - replace it with a 17T or even a 16T if where you are is very mountainous. Ignore the Hitchcocks' recommendations for a 19T.

The compression hike/squish band modification will help along with the above to give the plot a bit more poke, and that with the cam follower/tappet swap (and a properly hardened big-end pin and good quality main bearings) will give the sort of torquey and reliable bike you're after .

If AVL parts availabilty gets too tight the complete UCE top end will fit the AVL crankcases, you'll just need to run a custom rocker oil feed line to the oil temperature sensor take off in the UCE head. The AVL and UCE con-rod and big end are interchangeable too.

Hope this helps.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 01, 2018, 06:20:47 pm
Eric,

your riding and atmospheric conditions will be different to what I have been used to in the UK at not much above sea level. However, for general blattability (is that a word? It is now...) my Electra-X needed three things:

Happy Easter to all, here the holiday is over and I've got a little time this evening (and back to the bike in the morning).  But better to ignore my post than to let it get in the way of anyone's celebrating one of the greatest events in history... I'm in no big rush here...

Adrian, "blattability" is exactly what I was after - and I've never even heard of it...!!!

From what you're saying it sounds like I'm on the right track with most things.  Appreciate your take on the sprockets, heard conflicting views on this - mine is an 18T, but will be going from a 19" wheel to a shorter 120/80-18 tire, effectively lowering my ratio.  Though the 18T didn't seem too high even on 19-inchers, I hardly ever see "real" highways so from what you're saying I expect this should be fine. 

Carb options fewer here unless I import, and in that case spares could be a future issue.  So for now I might just drill out the ports in the domestic Mikuni (UCAL) CV's piston for a little better response - been done here on the UCE's 33mm CV with good results (taking ports to 1/8").  Here in the hills (and in Indian conditions generally) the pumper carbs tend to take quite a toll on fuel economy - I know of only one domestic bike that used one, and while notably responsive, it was also notoriously thirsty for a 150. 

Re: the header / pipe, my hot tube is out (could not have been good at maybe 3/4" ID), but my header pipe ID is still only 1-3/16 initially.  I did grind out the flange a bit so that flow would taper into it - but it's still a lot smaller than the port itself. 

***(having trouble inserting my attached photos here - how is that done?)

I had I heard that the export models had a different pipe entirely, is that true?  The old CI bullets have an unrestricted 1.5" diameter pipe right from the port, and I could probably adapt one.  Though in view of what ACE is saying, that may be counterproductive in the lower rpm ranges?  Mine seems to remain at 1-3/16 from port through the entire bend, opening up to 1.5 approaching the straight section (with hot-tube out).  Does this sound workable, with midrange the general goal, or should I be looking at something else?

Re: muffler/silencer, yes, I've heard reports of people getting harassed by law enforcement re: the "Goldies", and with things moving increasingly that way, am thinking of a long-bottle glasspack, which would be quieter but still free-flowing.  In any case, should ID of the silencer ideally be same as the rest of the pipe (1.5")?  They often make the innards much larger ID here for the sake of getting the deeper tone this seems to produce. 

Re: parts supplies, I'd found out a few weeks ago as you say that the con rod/crankpins were the same; and more recently through ACE here of the top-end adaptability (though as of now OE AVL cylinder kits are still available).  Mechanic here swears that the gearbox parts interchange as well, let's see when I get it opened.  So I think mostly I'd have to stock up on any of the unique electricals / starter sprag (could live without ES) / etc?  What about the cams / lifters, in the event of a UCE top-end? 

Thanks,
Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 01, 2018, 07:17:55 pm
AVL inlet cam is about.280" lobe lift. Rocker ratio is about 1.2. I say "about" because probably no 2 cams or rockers are the same.

Std Bullet cams and "S cams" are about. 312" lobe lift.

The AVL cams are the ones with the larger base circle.

If you want more low-mid rpm torque,  then advance the cams with the Hictchcock 3-way pinion. Also, do the compression increase and set the squish. Do the tappets and cam spindles as reliability mods. I would also get the Wossner 87mm flat top piston, and put that in.

Don't do iron barrel performance cams for low-mid power. They are for upper rpm power. Don't do a bigger carb for low-mid power. Make a longer header and longer inlet stack for low-mid rpm power.

ACE, thanks, great info/advice.  The basic principles take me back to V-8 tuning - advancing cams and utilizing long-runner tunnel-rams (/mopar cross-rams) for increased torque... and the opposite for high-speed power.

As delivered, the AVL seems a bit odd really - too big port, too small carb / header.  Wonder if even back then RE had in mind the possibility of varying tuning as per market preferences.  The big port would flow enough for 40hp and higher revs for places that wanted that, but the whole thing could be tuned down to run well below 2,000rpms, at 90mpg, where Indians largely like to keep 'em. 

535 Wossner piston is out of stock at Royal Motorcycles, don't know what other sources there may be, but anyway their pricing at near $300 was way out of proportion for this project - believe it or not, I'll probably have less than half that much in the entire rebuild, with decent quality stuff.  Didn't import bearings but the Indian NRB's are supposed to be decent (better than OE anyway), which is what I've got on the rod/crank.  The 84.75mm piston (510cc), made here by SAM (OE-quality), cost me about $12 complete in Delhi!!!  At any rate re-bore is done, piston fitted (.0025" clearance) and modded (2.5mm crown cut) as of last week, so think I'll stick with this for now. 

To clarify, I don't necessarily need more low end torque, I just didn't want to hurt it in pursuing the midrange / all-round performance. 
 
I couldn't find the "3-way pinion" in the timing section at Hitchcock's.  What is it exactly?  If the stock cams have 40 teeth(?), then advancing/retarding, with cams running at half-speed to crank, means 4-1/2 degrees per toothShould both be advanced or could there be particular benefits in doing only one or the other? 

Leaving aside aftermarket cams, is there performance to be gained by using standard CI units, being that the lift is apparently higher (my shortened cylinder could help compensate for the smaller base circle, I assume)?  But would this extra lift additionally strain the marginal strength limitations of the thin AVL followers?


You're so right about the manufacturing variations and as they say "the proof is in the pudding".  I've ridden a number of stock AVL's from this fleet - a couple of them, despite having great compression and every indication of being pretty fresh felt like I was riding a 350 - in fact on one solo test ride I could hardly get ahead of a 350AVL that had two adults aboard.  Switching carbs with that of a stronger-running bike had no helpful effect.  I remember another "identical" bike that seemed a lot more powerful than all the others - on-throttle, the rear tire would struggle for grip on dry asphalt.  The engine also vibrated somewhat more than the others.  And I wondered, being that none of these bikes were modified, what was making the difference...  Maybe it had the unintentional 1.3:1 rocker arms, or high-lift cams, or a lighter crank, or maybe the factory ran out of hot-tubes / silencer baffles - or maybe all the above???   ;D

I'd like to hear more about velocity stacks. Any calculators out there for optimizing lengths?  UCE 500 has a pretty long runner directly from the "toolbox" filter to carb, which might be pretty effective, whereas the AVL's have that apparently useless intermediate "resonator box" which is what on the older models housed the filter itself.  I mean, I'd like to know how long the stack / runner actually ought to be, depending on diameter, cylinder displacement, and proposed ideal rpm range.  If some extra length is going to net me noticeable power where I want it (vs. something mounted direct on the carb), then maybe I should try to adapt the UCE's rubber tube and keep the filter in the toolbox (which I'd otherwise hoped to reclaim for, well, tools - or else lunch).  Anyone out there actually experienced noticeable effects, or is this going to be pretty nuanced (my Honda 150 has probably ten-inch long stack right from the airbox, supposedly is tuned for torque, but still doesn't produce any oomph till 5,500rpm)?   

Same goes for the header/pipe & muffler (silencer), of which from what I understand smallish diameter but unrestricted path is what we want for torque.  I could see the point of extra length, too.  But how large/long is actually ideal - any calculators out there?  As mentioned above, my header is 1-3/16 ID from port to maybe end of the bend, opening to 1.5" in the straight section. 

Re: carbs my thinking is that the orig. 28mm was really put there for cost reduction / fitment issues (tight around the tank mounts for typical CV diaphragm-chambers), and acceptable only because Indians typically like to run Enfields at very low revs - but that otherwise, strictly speaking, it's pretty undersized for the application.  My 150 Honda came with a 28mm, and the donor bike for the proposed 32mm was a 220cc, its sibling being a 200cc with a 33mm from this same company (UCAL/Mikuni).  CV's are a bit tolerant of oversizing but I don't think I'm in any danger of that, and I doubt my low-end or fuel economy would be affected (till riding hard).  The UCE500's have 33's and are pretty grunty / efficient.   

That said, anyone have a clue as to initial jetting on this?  It's currently got a #115 main and a #15 pilot, as set up for a 220cc single; Would I have to be going to larger or smaller jets here (twice the displacement, more fuel demand, but presumably also bigger cylinder pulling more air through the same size venturi, thus more vacuum sucking more fuel up from the bowl - lower vacuum requires larger jets, right (?), which is why my 150 with the 28mm had a big #132 jet, whereas a Bullet 350 with a 28mm uses a #95???)?  I've got a fairly wide range of jets on hand from 95 to 132 for the main, in pilots I think I've only got #20/15's.  Any thoughts/experience here? 

Still trying to decide about the tappet/guide upgrade...

The CI's stems are 9.5mm, the AVL's only 7mm, which does seem small considering the loads/speeds they're being subjected to.  Fleet owner confirms he's never seen a failure in this whole decade in the context of (highly grueling) tours, but occasionally on privately owned and less carefully maintained bikes; Again credits the difference to his extremely frequent oil changes, which kinda makes sense: additive breakdown = more friction on lobes/tappets = greater side loads = greater stresses on that thin stem = more likelihood of breakage.  Other possibility is partly RE's typical quality control - possibly some will never break, while others break early on / unpredictably? 

Just having a hard time understanding how the AVL-upgrade engineers could've made such a "mistake".  Could they have been assuming normal material strengths that in reality were never realized in Indian production?  I'm assuming they were trying in thinning them to make the valvetrain lighter...  And that gets me thinking of the problem these have already got with valve float - the CI tappets are definitely a LOT heavier, and I don't really want to get into aftermarket valvesprings and such. 
 
Thinking more about it, also not very confident about the level of lathework possible locally - huge machine I've got available must have about a 2-foot swing and huge chuck, not very suited to small-diameter parts - I'd really rather be using a collet to hold the guides for this level of precision, and to save the threaded portion, from which I'd have to hold it - but have yet to find a collet-equipped lathe in this land.  The OD is going to be critical as it's a press-fit piece (threads are only there to give the extractor/puller something to grip).  Also a little concerned about any need of modded pushrods, as they wouldn't exactly be available roadside in the event of some failure whilst touring. 

The CI/AVL tappets themselves measure almost exactly the same length, so pushrod length should not be much issue - but main trouble is that the CI's don't have the little socket built into the top of the tappet stem, which on the AVL's is what locates the pushrods.  Guess I could make a little cap above the lifter stem as the CI's used, but with the socket on the top face? But likely won't find toolbits here locally for making that radiused recess, and probably there are material contstraints (tool steel or?).  Tappet stems themselves presumably being hardened, don't think I could machine those sockets into the tappets directly AVL-style; And barring these options, we're speaking of hybrid pushrods (old-style lower ends with AVL top ends?) which may or may not be a pain to fabricate.  Or am I just supposed to use the CI pushrods (are the tops the same, workable on AVL rockers?), whereby my CI-style "socket" is on the lower end of the pushrod, and would match up to the cap atop the lifter?  In this case, does the stock length rod work?  And if so with which - the AVL or CI cams? 

Sorry, I must be exhausting you all... :)

And if I go further I'm going to get confused myself...

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 01, 2018, 11:07:56 pm
On my AVL hybrid I used the longer exhaust pushrod in place of the inlet pushrod, and screwed in a late iron barrel tappet adjuster which used the same 6mm thread as the AVL version. For the exhaust I used the exhaust push rod and tappet adjuster from a 500 iron barrel engine, I made a bronze bush and fitted it to the top of the alloy section of the rod and pressed the top of the old inlet AVL pushrod into that. This means I have one metric and one imperial tappet adjuster, but nothing I can't live with!

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 02, 2018, 10:58:15 am
Exhaust header pipes - The iron barrel 350s use a 1.5" outside diameter pipe, the 500s use 1.75". Some 350 pipes are swaged to 1.75" at the muffler end. Apart from the odd reduction at the cylinder head end which your pictures show, the 500 AVL and I believe the 350 AVL also have 1.75" O/D pipes. Over here you can get unrestriced AVL pipes from Hitchcocks' which are 1.75" O/D for their entire length.

There is a school of thought that an unrestricted 1.75" pipe is actually too much for a 500 Bullet. In the UK there was a classic bike dealership that raced Indian built iron barrel 500 Bullets in the 1990s, one of their tuning tricks was to fit the 1.5" header pipe off a 350 to speed up the exhaust gases. You can possibly fit the pipe off a 350 I.B. but it will need modifying to fit the AVL head's 1.75" exhaust port and fixing flange.

For purely styling reasons both my old Electra-X and the current AVL hybrid ended up in street scrambler guise using the high-level exhaust for the Woodsman model. (Historical note - the English Royal Enfield factory sold their motorcycles under the Indian badge in the USA in the late 1950s, the Indian Woodsman was one of the variants based on the 500 Bullet at that time. Nothing to do with actual Indians building Bullets in India). These pipes are made from 1.5" O/D tube (easier to bend) but swaged for 1.75" ends.

Every 500 AVL cylinder head I have seen has a very badly finished and restrictive exhaust port, so much so that the Hitchcock pipes actually come with a removable steel collar insert which (sort of) lines up with what's left for the gases to escape.  It's no big deal to open out and clean up the port a bit to match the I/D of whatever header pipe you end up using.

I know what you mean about the 500 AVL's sluggish performance, the 18 to 17T sprocket swap really did make the thing much more fun to ride with a bit more poke off the line in city traffic, without sacrificing anything in top end.

A.


Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 02, 2018, 06:06:22 pm
Exhaust header pipes - The iron barrel 350s use a 1.5" outside diameter pipe, the 500s use 1.75". Some 350 pipes are swaged to 1.75" at the muffler end. Apart from the odd reduction at the cylinder head end which your pictures show, the 500 AVL and I believe the 350 AVL also have 1.75" O/D pipes. Over here you can get unrestriced AVL pipes from Hitchcocks' which are 1.75" O/D for their entire length...

You can possibly fit the pipe off a 350 I.B. but it will need modifying to fit the AVL head's 1.75" exhaust port and fixing flange.

The trouble with mine is that there's an inner pipe the entire length of that header bend, and at only around 1.188"ID, a lot smaller than even the 350 pipes, which I should probably look into. 

My port was way off-center in relation to the pipe recess.  Hence the gasket was badly obstructing the flow path.  Really bad.  I did some regrinding to get it more concentric and re-sized the gasket, but it still seems that my header pipe's ID may be a lot smaller than it should be.

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 02, 2018, 06:25:07 pm
Adrian (or anyone else), one more thing: 

I'm held up on the refitting at the moment because I rather stupidly let my top piston ring get broken whilst carrying the set in my knapsack (Aaaaargh!!!).  This was a +0.75mm (.030") oversize kit, and now can't find replacement rings here on the street. 

Ebay shows ring kits of this oversize being exported from Delhi suppliers (they get more money out of you guys than the domestic market) so they must be available here someplace. 

Thing I need to know is whether rings are the same size on all Bullets, CI/AVL/UCE - Are the (compression) rings the same 84mm diameter/ 1.5mm thickness on all these?  Listing says only "500cc Bullet". 

Ridiculous, but worst comes to worst, I'll have them shipped from India to a friend in the U.S. who can re-import and hand-deliver them to me when he comes over here in May... oh, brother...

Trying to contact the suppliers directly and see if we can arrange in-country delivery (preferably at domestic prices???).

-Eric

Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 02, 2018, 11:30:17 pm
Sorry I can't advise on oversize piston rings, oversizes have only recently become available for the UCE models here and I don't think +.030" is a size we have. The 87mm piston doesn't count!

That small bore inner pipe in the exhaust header is meant to be there as part of the Lean Burn set-up by which the AVL models were touted as being more eco-friendly. I gather other people have succeeded in removing it, but you might be able to adapt an I.B. pipe if you can't get the Hitchcocks' unrestricted pipe from the UK.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 03, 2018, 12:25:34 am
If you are okay with the current top speed,  then you could keep the small ID header for torque. A bigger header ID will lose low rpm torque.
Your best bets are displacement and compression. If you want to adjust cams, go with the advanced timing g pinion.
Title: Re: First AVL ownership/build... tech questions...
Post by: Bullet Whisperer on April 03, 2018, 09:46:58 am
Great care must be taken if advancing the inlet cam - the inlet valve gets very close to the piston crown on standard timing and this is one of the reasons I have retarded the 'S type' inlet cams by 1 tooth from the marks on some Electra X engines I have tuned.
 Here is one such machine, with shortened barrel, 'S' cams [inlet retarded] and Amal carb going about its business. The first machine I tuned gained bottom, mid range and top end power as carb sizes increased from 32 to 34 and finally, 36mm. It ran 19/38t gearing [with 18" rear wheel] and went like stink, from idle to flat out at 103 mph. The one in this video will do well over 90 mph.
 B.W.

 https://youtu.be/obBjjB4nPiw
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 03, 2018, 12:39:26 pm
Great care must be taken if advancing the inlet cam - the inlet valve gets very close to the piston crown on standard timing and this is one of the reasons I have retarded the 'S type' inlet cams by 1 tooth from the marks on some Electra X engines I have tuned.
 Here is one such machine, with shortened barrel, 'S' cams [inlet retarded] and Amal carb going about its business. The first machine I tuned gained bottom, mid range and top end power as carb sizes increased from 32 to 34 and finally, 36mm. It ran 19/38t gearing [with 18" rear wheel] and went like stink, from idle to flat out at 103 mph. The one in this video will do well over 90 mph.
 B.W.

 https://youtu.be/obBjjB4nPiw
Good point, B.W.

I neglected to mention the piston/valve concern.

On the few AVLs that we have done, we were able to do the squish mod with 1.8" inlet valve, and stock cams, and still have .032" piston /valve clearance, which admittedly is closer than I would normally recommend.  Advancing the cams in that situation would be  out of the question unless a valve relief was cut into the piston.
Title: Re: First AVL ownership/build... tech questions...
Post by: ERC on April 05, 2018, 02:24:59 pm
Great care must be taken if advancing the inlet cam - the inlet valve gets very close to the piston crown on standard timing and this is one of the reasons I have retarded the 'S type' inlet cams by 1 tooth from the marks on some Electra X engines I have tuned.
 Here is one such machine, with shortened barrel, 'S' cams [inlet retarded] and Amal carb going about its business. The first machine I tuned gained bottom, mid range and top end power as carb sizes increased from 32 to 34 and finally, 36mm. It ran 19/38t gearing [with 18" rear wheel] and went like stink, from idle to flat out at 103 mph. The one in this video will do well over 90 mph.
 B.W.

 https://youtu.be/obBjjB4nPiw
      Neat video, I wonder who trims all those hedges along the roads. Could be a money maker for landscapers.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 06, 2018, 02:00:53 pm
Adrian: I think what most people have succeeded in removing is actually the "hot-tube" in the last six inches or so of the header pipe, that being a tiny 3/4" ID.  Done that.  But even if it were possible to remove the entire inner pipe in the bent area (can't imagine how), on Indian headers you'd still have a restricted area the first couple inches from the port, where even the OD is stepped down to maybe 1-1/4". 

ACE: I really appreciate your time/perspective as an experienced and pretty distinguished tuner.  Could you refer me to a good calculator for intake tract / header lengths/diameters?  Really would like to optimize this eventually, if possible.

BW: Thanks for that video and other inputs.  You may know that in India you would be respectfully addressed as "Guru-Ji" - your exploits have clearly raised you to that status and having now watched a few of your YT videos, am really appreciating the kind of simple, grassroots approach to things you've taken (seriously, a socket/extension hung in the crankpin hole for balancing...???  A propane torch for gas flow???  I love it!!!  And it works???!!!). 

So thanks again fellas.  Great info / insights here. 

Mmmm… so retain/enhance the typical low-end torquer Bullet attitude via advancing the cam, keeping the small header - or else bump up the midrange by maybe retarding the cam, bolting on my BS32 carb and a modded CI350 pipe…  Neither option will cost me much apart from a little time, and I can wait to finalize.  Will first try it “as is” (basically just the compression/squish mod, hot pipe removal and very minor port/head work), break it in a bit, and see what I’m most inclined towards.  We hardly have opportunity to ride above about 50mph up here, and torque is a boon on hairpins / inclines, but still, a strong midrange “ramp” has always held a certain satisfaction and is useful in its own way (and a little easier on drivetrain components maybe).   Let’s see.   

Speaking of drivetrain, I had the gearbox apart a few days back – not too bad a job though getting the whole assembly back in the case in one go – specially with regard to the selector disc - is slightly tricky and required the help of our own local shop "Ustaad" ("master" - incidentally the one who had insisted that these gearboxes never go bad???).  As suspected the engagement “dogs” on a couple gears were looking a little more trapezoidal vs. castellated (if that makes sense) - this did not seem to impress him much.  Anyway, apparently too many inexperienced bikers over too many years on an unfamiliar bike making countless gear changes heading up 17,000+ft. passes, and missing a few here and there.  With no new gears on hand and a little past success with a grinder / diamond files, I worked a prime example of Indian “juggad” that may actually work (am sincerely hoping so).  Also replaced the indexing pawl spring, which seemed a little weak vs. the new one I was fortunate enough to find (its significance likewise lost on ustaad-ji).   

The engine is mostly together as of yesterday, and re-mounted in the chassis.  Bought another new piston kit to provide for my broken ring – cheap enough here, and hope eventually to find the ring set sold alone to use on the extra piston / some future project.  Turns out the old CI ring is 1/16” (.0625) thick, vs. the AVL’s 1.5mm (.059”), so that’s not gonna work unless I alter the ring groove.  There are just so few of these 500LB’s over here country-wide, and the quality of re-boring work has been so poor for so long that most people learned the hard way to install complete new standard-sized kits (even at ten times the price).  In my case, really had to sit there and insist on the guy putting my cylinder back in the honing machine (three times!) to get the clearance right.  Little understanding colloquially that the larger the piston/bore, the more expansion you’re going to get / more clearance you’ll need.  Any attempts at illuminating the average third-generation technician here and the response is usually, "You know the theory, we know practically".  Some truth in it, but what I do know very practically is that the cylinders they bore end up with seized pistons extremely regularly (read the Indian forums and it's every Bulleteer's greatest fear) - Short of light trucks, this is about the biggest piston in India and they try to set it up the same way they would a moped’s (which they also set too tight, in the pursuit of "long life").  Anyway.  This has been quite a process. 

In truth the crank was not really done to my satisfaction either (old pin retained, with oversized NRB rollers and the typical honing out of the rod, another multi-gen guy here claiming - rightly - that the RE-supplied pins were junk and as mine (made here by MACO) was in good shape it was probably safer to just leave it in place).  Their date-mark was stamped on the crank from when they'd done it in 2011, and if it would do another 6-7 seasons of riding over the passes I'd be reasonably satisfied - but there are signs (to me) that the pin, even if hard enough, wasn't entirely round... oh, brother...

Admittedly he got the crank assembled fairly straight (at least a lot better than some of the RE factory's work - BW's related YT video illuminating here) even without a dial indicator (never seen one used in a crank shop here).  I'd brought one along and he was willing to humor me...  0.04mm runout, the published spec being 0.08mm max... Says I should expect 25,000mi out of this, let's see.  Would've liked better, wish they'd have cleaned out the oil passages with fresh solvent - but they know everything and have been at it for years, and the gracious friend transporting me and my 10kg crank had been waiting a long while for us to get done...  Hope I will not be facing any regrets too soon.  Anyway, these are the pains of trying to do a decent quality build in the AVL's land of origin.   

Squish seems to have worked out, as the squished whole-wheat lump suggests.  Eliminated the 0.5mm cylinder base gasket in favor of high-temp RTV, but had to re-surface the cases a bit (emery cloth, a thick slab of plate glass, and patience - the traditional Indian way), which were not very nicely matched (cylinder rocked on them) and moreover badly scarred by whichever previous hack mechanic.  Managed to find a head gasket that was around 0.3mm thinner than others in the stack of genuine RE ones I checked (one plus side to the OE’s large manufacturing inconsistencies).  Long story short I seem to be just shy of 1mm squish. 

With stock cam timing (should check advanced also), valves seem surprisingly to be coming nowhere near the piston despite its topping out a bit above the deck now – maybe in part because I didn’t replace the valve seats but re-cut/ground them, raising everything a fraction.  Or maybe because my particular inlet cam was factory-retarded?  I could make up a degree-wheel but feeling I've got a lot of time in this already, want to get it basically running. 

Waiting on assembling the primary drive for lack of an elusive rubber seal (the slim one between the gearbox input/output shafts).  Supposed to be one coming up from Delhi.  And on the flip side are the cam spindle sleeves, which are badly worn (should’ve noticed it earlier) – bought new ones an hour away from here that must be (CI) imperial-sized, because while a perfect fit inside the cams themselves, they won’t slide over the studs in the case, being a fraction smaller in ID.  Some difficulties / delays ordering stuff here in the greater Himalayas, the internet / mail order are not really developed for motorcycle spares and you kind of need a friendly local parts-man on your side, who doesn’t mind wasting his time on your petty desires (thus far at least one is tolerating me).  And as I said earlier, even in Delhi I think the AVL spares are getting sparse.  By Indian law RE is supposed to supply them for 15 (10?) years from the date of manufacture, but that is almost always violated by all the vehicle-makers.   

Thanks again to all for the help, I hope to have this thing fired up by Monday afternoon, and just hoping/praying it all fundamentally “works” and will be making all the right noises.   

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 06, 2018, 03:11:53 pm
P.S.:

Forgot to mention: adjustments wound almost all the way down, my pushrods were just barely short enough to cope with the approx. 2.5mm shaved from the cylinder bottom, and the elimination of the base gasket, and the valve stem ends being a little higher on account of the re-machined seats (and this is with a 1.5mm thick head gasket).  Looks like it'll work.  But just FYI for anyone else doing a similar compression mod, 2.5-3mm seems about the max do-able in terms of stock pushrods. 

And re: cam timing, still wanted to get this straight:  40 teeth / 360degrees = 9 degrees of cam rotation - but that's only 4-1/2 of crank rotation... which I thought is what we were working off when speaking of valve timing.  And our host's adjustable pinion (which I still can't find on the site) is supposed to be 4-1/2 degrees fore/aft... in which case, wouldn't that be the same as one tooth? 

Bit confused here.

Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 06, 2018, 03:43:11 pm
Oops...  crank degrees double the cam, right...?  So 18degrees either side when advancing / retarding a tooth.  That's quite a lot actually, and I could see where the result could be considerable, maybe excessive even, depending how much (and to which side) one's particular cam varies from OE spec. 

I need to rest my brain, apparently.
-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 06, 2018, 06:27:20 pm
Oops...  crank degrees double the cam, right...?  So 18degrees either side when advancing / retarding a tooth.  That's quite a lot actually, and I could see where the result could be considerable, maybe excessive even, depending how much (and to which side) one's particular cam varies from OE spec. 

I need to rest my brain, apparently.
-Eric
Yes, it is 18 crank degrees.  I think it can be a good choice to relieve the piston for valve clearance for a goal of low-mid torque.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 06, 2018, 11:49:13 pm
Eric,

sorry, forgot to mention that the ends of the adjustable cam spindles (the circular nuts with the spanner flats) are 15mm diameter where they sit in the AVL timing cover. The I.B. spindles are 5/8" or 15.88mm all the way along, so yes, you will need a 5/8" reamer or drill in the timing cover where it sits over the cam spindles if you swap to solid spindles.

One other thing I have noticed on all the 500 AVL heads I have seen is that the outer edges of the valve seats actually protrude into the combustion chamber by about 1mm. Cutting the seats back so that the outer edges are flush with the combustion chamber will give you a little more piston to valve clearance, though it sounds like you might already have done this.

A.

Title: Re: First AVL ownership/build... tech questions...
Post by: DanB on April 07, 2018, 05:45:06 am
Cool build and great narration. Looking forward to the next installment.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 10, 2018, 02:54:03 pm
Anyone have any advice for me re: initial startup after rebuilding?  All's ready for tomorrow morning (Indian Standard Time).

When I used to start up freshly refitted engines in cars the main concern was oil pressure, making sure it builds before too long.  Mechanic here says on Enfields it can take a LONG time to show up at the banjo bolts on the head... I don't see why it should take so long, but anyway main concern is the crank/piston - is there any way to know that oil's arrived there?  Despite having read a description, the lubrication system is still a little confusing to me. 

Also just advice re: initial run-in... I'm going to assume my re-bore isn't extremely round, nor is it set up very tight.  Top ring is chrome, scraper is cast-iron.  Crank is re-done and fairly tight clearances there.

I've rebuilt a lot of engines, but all were either V-8's or two-strokes, also one 2.5L wet-sleeve diesel. 

Though basics are the same, this somehow seems like a different animal... and I confess I'm struggling a bit despite taking at least ten times as long to do this as the average Indian street mechanic...

Thanks,
Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: tooseevee on April 10, 2018, 03:58:20 pm
Anyone have any advice for me re: initial startup after rebuilding?  All's ready for tomorrow morning (Indian Standard Time).

When I used to start up freshly refitted engines in cars the main concern was oil pressure, making sure it builds before too long.  Mechanic here says on Enfields it can take a LONG time to show up at the banjo bolts on the head... I don't see why it should take so long, but anyway main concern is the crank/piston - is there any way to know that oil's arrived there?  Despite having read a description, the lubrication system is still a little confusing to me. 
Thanks,
Eric

           The engine work on my '08 was not as extensive as yours. It consisted mainly of headwork by Ace and Mondello's, but it was not run at all for over a year all the same.

           All I did was leave the banjos loose while I kicked it over. IIRC it took about a dozen kicks to have oil oozing out. If you prelubed everything, as I'm sure you did, it should be fine. Look how horribly these engines are treated in India and they keep plugging along. I think thousands of them run for years with just barely enough oil and maintenance to keep them gasping and struggling along. AND with a 400 RPM idle they seem to love in India.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 11, 2018, 10:31:35 am
. Look how horribly these engines are treated in India and they keep plugging along. I think thousands of them run for years with just barely enough oil and maintenance to keep them gasping and struggling along. AND with a 400 RPM idle they seem to love in India.

Well, I did pre-lube everything... just this slight concern that maybe I forgot something / got something together wrong (couple earlier oversights were caught).  I wasn't very careful disassembling because I believed I'd have professional oversight at the point of re-assembly (ultimately very infrequently!). 

You've got a point about the treatment of Indian Bullets (though 400rpm sounds on the high side... :) )

The one here in the photo just came back yesterday from a tour of Kinnaur/Spiti valleys - very rugged, remote places.  I'd spent a few hours astride this bike just before that; feels like brand-new to ride it - powerful, quiet innards, steering, suspension, brakes, gears spot-on and even good tread on the tires - despite its presumably being subjected to this sort of treatment pretty regularly.  One part of me wishes I'd been able to buy this one instead of mine... Would've been a lot less work, though doing it this way I've received a pretty extensive education (just hope it works). 

Snowed unexpectedly this morning so the workshop wasn't really open / in operation. 

Tomorrow...

-Eric

 
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 11, 2018, 10:54:27 am
Exhaust header pipes - The iron barrel 350s use a 1.5" outside diameter pipe, the 500s use 1.75".

There is a school of thought that an unrestricted 1.75" pipe is actually too much for a 500 Bullet. In the UK there was a classic bike dealership that raced Indian built iron barrel 500 Bullets in the 1990s, one of their tuning tricks was to fit the 1.5" header pipe off a 350 to speed up the exhaust gases.

Thanks for the tip - Yes, everything I'm reading online suggests that 1.75" would be quite oversized for a 30-50hp engine.  Even a 1.5" is supposed to be able to support up to 80hp according to one source. 

Rpm at torque peak reduces by some few hundreds per 1/8" of pipe diameter apparently.  So in the low-down-thumping, fuel-economy-obsessed Indian context, a 1-1/8" header ID probably made good sense; This squares with what ACE has been saying,  though the old iron 500's with their "oversized" pipes didn't seem to run badly either, and I could wonder if something this small is overdoing it.

I'll see how it works now that the port is matched, the tiny 3/4-ID "hot-tube" (wonder what that thing actually is) removed, and a thinner-section gasket that doesn't block the path is installed. 

I did wonder whether whatever smaller-diameter header ID ideally should actually be extended some instead of opening up into 1.5+ after the bend.  V-8 headers seem to often be of 30" or more in primary tube length, but in multi's there are other considerations of course. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 11, 2018, 01:26:24 pm
Given your stated parameters,  I recommend running the pipe you already have.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 13, 2018, 06:00:27 pm
The bike's thankfully up and running!

Not being scientifically measured, performance assessment is prone to subjectivity - I'm looking forward to riding another healthy, stock fleet Machismo or two to compare side-by-side... BUT meanwhile my initial impressions are very positive:  As desired, it seems very punchy and responsive, with a healthy thrust from low rpms in pretty much any gear - this is with the stock 18T sprocket and 19" rear tire.  I could probably pull a 19T easily enough, maybe even a 20T if/when I move to the 18" tire.  Not really revved it much yet, so that part remains to be seen, but thus far it feels pretty entertaining.  With the hot tube out of the header, it definitely sounds a lot better than it did earlier, too. 

Besides the performance change, the compression increase is noticeable when kickstarting (still starts easily though, without decompressor) and when decelerating.  No apparent increase in vibration.  On the first run heard a little detonation at certain throttle openings, but after refueling on some other cheap Indian fuel, not observed at all, so I think we're okay there.   

No adverse sounds coming from the crank/piston now, and the gearbox is definitely in order, with not a single false neutral / any popping out of gear on a few runs down to town and back. 

With members' experiences / advice falling on either side and not a lot of time to re-open and cut valve reliefs, ended up timing the cams to the marks, partly so I'd have a baseline to work from.  Same with the carb - it will make effects easier to compare/evaluate later if I know how it's running closer to its original form.  Did raise the needle a notch, as the bike always seemed lean and hot even before the compression / pipe changes. 

It's got an oil leak in the primary drive housing someplace that I need to resolve (new gaskets / seals, so a little mysterious). 

ATF in the forks now which is about right - not too firm or spongy.  But handlebar sits to the right a bit when driving straight, so something not quite right up there and I'll have to get into it. 

More concerning, I've got blowby pushing a LOT of oil out the crankcase vent.  I suppose the higher compression probably exacerbates any incomplete ring sealing at this early stage?  I remember someone else in one of the forums having this problem initially, and am hoping it resolves itself before long.  Fleet owner had told me earlier that these AVL's do that a bit when especially heated up, but it wasn't running hot, and this is definitely WAY beyond normal.  I remember some talk of the possibility of converting to an older vent system...  Mine is just a plain plastic pipe out of the top of the engine case, but I don't know where it actually taps in to the innards.  Any advice / experience there appreciated.   

I put the double seats (front springer) on it yesterday and will probably get working on that oil leak tomorrow.   Cam spindles and possibly pinion still need replacing as there's still some noise on that side and no adjustment leeway left on the exhaust pinion eccentric.
   
I've been riding a 13.5hp 150cc Honda since the RE has been apart, and of course this feels very quick compared with that.  I'm not pulling unintentional wheelies, and I don't think it's going to prove as quick as my DR350S, but then that's a torquey 30hp engine with a light flywheel in a 130lb chassis.  What I'm sure of is that freshly rebuilt, this thing (in true Indian fashion) pulls our family of four (!) much better uphill than it could earlier, when it used to feel pretty sluggish.  Even with all that weight, twisting the throttle now really pushes (us) back. 

Thanks to all for the helpful advice / inputs through this process. 

And again, if anyone can tell me something about this blowby / crankcase ventilation I'd like to hear it.  How long could it take for the chrome top ring to get properly seated, and is that quite likely to resolve the problem? 

-Eric 

For anyone who doesn't know what a Machismo is, photo of ours is attached:
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 13, 2018, 08:49:49 pm
To seat a chrome ring, you need a slightly coarser hone, and you have to be vigorous with the break-in. Don't baby it too much, or it won't seal right.
The way to do it is work it up and down with some pretty good load, and then shut it off before it gets too hot. Let it cool down and do it some more. About 5-10 minutes at a time usually works good.

It will get spit-boiling hot pretty quickly in the early break-in, so keep an eye on it.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 13, 2018, 11:37:47 pm
Quote
More concerning, I've got blow-by pushing a LOT of oil out the crankcase vent.  I suppose the higher compression probably exacerbates any incomplete ring sealing at this early stage?

Also check the oil tank hasn't been overfilled. The engine breathes through a hole in the casting wall between the crankcase proper and the oil tank section of the main crankcase casting, and out through the union at the top, instead of the pre-2004 vent on the left-hand side of the crankcase. If the breather catch-can is the same as the 500 AVL export models the catch can then is supposed to return expelled to the engine via a pipe to the back of the timing case with a short duckbill inside as a non-return valve. There's also a short duckbill inside the catch can as the main non-return valve.

It is possible to block off the hole between the crankcase and oil tank and fit a breather take off in almost the original position on early 500 AVL, or even drill out the unused breather stub if it hasn't been polished under-size. Sorry, should have mentioned that while you had the cases apart! Late AVL and C.I. Bullet (post 2006?) don't have the now vestigial breather stub, but it should be possible to drill thorough and tap for some sort of union (my project uses a 1/4" BSP by 1/2" stub hose tail) for a breather pipe in the side of the crankcase where the classic breather sat. With this you can fit one of Hitchcocks' oil filler neck extensions which takes any surplus oil back to the tank, remember to fit a non-return valve between the breather outlet from the crankcase and the filler neck extension.

Despite the 500 AVL being a home market model several have escaped to the UK, where we were only offered the Electra-X officially (same disk front end, smaller front fender). In the USA they were offered both the Electra-X and the 500 AVL Classic, which very similar to the 500 Machismo except for the standard drum brake 500 Bullet forks and fenders.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 14, 2018, 05:49:14 am
Also check the oil tank hasn't been overfilled.... If the breather catch-can is the same as the 500 AVL export models the catch can then is supposed to return expelled (oil) to the engine via a pipe to the back of the timing case with a short duckbill inside as a non-return valve. There's also a short duckbill inside the catch can as the main non-return valve.

It behaves as though overfilled - just raw oil being pushed out with vent gases, not an oil-mist.  Could the hole between the crankcase/tank have been factory drilled a little lower than usual?  Or is 2.5L too much - I put that quantity in there because it's what the shop hands told me to do - and they should know.  Round, smooth dipstick is next to impossible to read with clean oil, and in truth haven't really tried to check it the "proper" way (as a dry-sump).  Anyone done something to improve that dipstick?  Thought of grinding one side flat and filing the typical hatch-pattern in it...

I suppose that aluminum shavings are soft enough as to not damage critical things, so maybe can still drill/tap into the crankcase for vent relocation if resolution doesn't come by whichever other means.

The bike doesn't have a catch can at all.  The duckbill is there inside the timing cover, but from the nipple on the backside, there's what looks like an OE molded rubber pipe running (along with the main vent pipe) into the swingarm area - which of course would have zero functionality.  I suppose I should be thinking of retrofitting some kind of catch-can at minimum, so that whatever comes out can at least be reclaimed.   

Ace - The hone pattern was quite a bit finer than what I've generally done on my own.  Was done in a proper automated machine and it didn't occur to me to go over it with my rougher hand-drill three-finger hone.  I'm almost always running uphill or downhill and quite a few full-throttle bursts (not at high revs), so not going too light on it.  I'll take your advice, ride it a bit hard, put in a few hundred km's and hope for the best. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 14, 2018, 05:55:35 am
It is possible to block off the hole between the crankcase and oil tank and fit a breather take off in almost the original position on early 500 AVL, or even drill out the unused breather stub if it hasn't been polished under-size.

I'm supposing that if the existing oil-tank-based breather's external fitting was blocked with a cap-plug, and a new opening / fitting fixed on the crankcase side, it wouldn't really matter if a hole was still there between the case sections? 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: DanB on April 14, 2018, 08:05:57 am
Quote
2.5L too much?

Yes, thats is too much. I usually put in between 1.25 and 1.75 L depending if i change oil filter. Fill to the halfway mark on the stick.

For the breather, try running the hose from the oil tank straight up and then to the can. Reverse it basically.  Block of the return line to the timing chest; that becomes your drain from the can. Ignore the hose to the primary. Doesnt do much either way. I can take pics of mine if youd like.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 14, 2018, 02:35:52 pm
Not sure what a duckbill is doing inside the timing cover. The duckbill belongs outside the engine.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 14, 2018, 04:32:48 pm
Not sure what a duckbill is doing inside the timing cover. The duckbill belongs outside the engine.

The late factory breather set-up has two. The first one is inside the catch can on the exit from the breather pipe. This is effectively the external duckbill as used on older models. The second duck bill in the timing chest is supposed to be a non-return valve (just not a very good one) for the return line from the catch can, by which surplus oil in the breather is returned to the engine, at least according to the plan.  ::)

If you're thinking of fitting an external breather union to the l/h crankcase you can probably avoid getting alloy swarf into the engine if you're careful, but at the very least you'd need the top end off to ensure breakthrough was as gentle as possible and for stuffing the lower crankcase mouth with loads of rag. Not sure how effective an external breather would be with the hole between the crank chamber and oil tank still open, though.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 14, 2018, 05:11:24 pm
Yes, thats is too much. I usually put in between 1.25 and 1.75 L depending if i change oil filter. Fill to the halfway mark on the stick.

For the breather...
I can take pics of mine if youd like.

Sure... a pic or two would be helpful - I don't even know what the can looks like / where it mounts.

I guess I'm substantially overfilled, that's likely the problem, fits the symptom.  I wonder how these techs got that wrong, being that they service 30-odd of these bikes?  They stock oil in 3L cans, 2.5 for the engine, 500mL for the primary, they say.  Weird. 

Mine doesn't have a catch can at all right now, I'm pretty sure that none of the AVL's here had them as OE.  I need to check if some other model of Bullet came equipped with it, if so can probably order and retrofit. 

Or if filling with less oil minimizes the amount being thrown out, I can just leave things as they are and fix the end of the vent down near the chain for auto-lubing (though I've got an o-ring chain now anyway).   

***
I put some more distance on it today, ran up-valley several km's, a fairly steep/steady climb.  I went a little heavier on the throttle, a few more revs.  Engine didn't get noticeably hot doing it, I think richening the carb has helped, it actually seems to run cooler now than before the rebuild.  Running very strong low / lower-mid, and no detonation at all.  I'm sensing that the power's going to taper off pretty substantially at high-mid to higher rpm's though - it just doesn't seem to have that kind of "ramping up" of output that I felt in the cast iron 500 I rode recently (though this one is definitely stronger down low).  Might try bolting on the 32mm CV carb / filter setup next week and gauge the effects; Besides being highly convoluted/restrictive and taking over my otherwise useful side box, the stock inlet setup is pretty leak-prone, so I want to be rid of it considering how dusty it can be up here. 

If after some time with it I feel I still want more pull further up in the range, as per various recommendations here, I can think of retarding the inlet cam (or else maybe going for stock cast iron cams?) and fitting the 1-1/2" 350 pipe.  I think that's about the extent of what I'd want to do with it, it runs great and hasn't cost me much to put together. 

Resolved the leak (I think) in the primary case today - I believe what caused it was my mistake of installing the shaft seal behind the clutch before fitting the housing to the engine/gearbox.  Because production variations can alter the distance between the crankshaft and gearbox output shaft slightly, that seal needs to be installed after the inner housing half is bolted to the engine/gearbox.  The four mounting holes around the seal are oversized to allow the seal to center on the shaft before tightening down the bolts.  The other potential culprit was a 10mm nut missing from the stud coming through from the gearbox behind the clutch.

Basically very pleased with how it's running, it's going to be a lot of fun around here locally.  Even my wife felt the difference in responsiveness and pull (not sure she appreciates it entirely, though!).  Earlier it took a few revs for power to build up, now it's just so immediate - despite its being CV-carb'ed. 

Again, only changes were the .030" overbore/compression mod/squish, 3-angle valve job, very mild port/chamber work, removing the hot tube, and slightly opening up the header gasket and matching the header flange/inlet to it.  I'm going to say it was worth that much trouble.  Cylinder leakdown was minimal before starting the work, so whatever improvement is there is due mainly to the changes rather than the freshening up. 

I would expect that as the engine gets more fully broken in, the performance should increase slightly. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 15, 2018, 03:59:10 pm
Here's the quick and dirty breather fix with the outlet on top of the oil tank, point the duckbill over the countershaft sprocket, it works fine if you don't overfill the oil or ride with too much ethusiasm, which given your efforts to liven the engine up a bit is a distinct possibility! If that still makes too much mess of the back of the bike, remove the short duckbill, fit a metal non-return valve and a longer piece of hose running to the back of the bike.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 16, 2018, 06:10:51 pm
Well, I had a look at the (Indian) "Discontinued Models" parts catalog this morning and discovered that Indian AVL's indeed DO have the PCV breather canister.  Asked the mechanic who confirmed it's there under the seat someplace and that I should clean it.  Took me awhile to find it - it's much smaller than I expected.  I removed, cleaned (wasn't much of anything in there, not having been connected recently), hooked up  the pipes, and we'll see how it works in stock form, particularly once my oil level has settled out to wherever it's supposed to be.  I just let the canister vent out near the chain, I don't really want it near the air filter. 

My duckbill doesn't seem to operate very well as a check-valve though - I suspect age-hardened rubber.  Will have to see if these are available new still. 

Came out this morning to take my son to school, got 20ft out and realized the rear tire was flat - big old bolt sticking out of the tread.  Already had a new rim waiting, so went ahead and did the changeover to the 120/80-18 rear (Dunlop) and 90/90-19 (Ralco, fairly soft compound) front today.  Had to re-drill the front mudguard mounts to lower it 3/4" to match the smaller diameter.  Kinda gives the bike a kind of lower, longer look - overall better I'd say, though I'm giving up a little ground clearance (a justifiable Indian obsession).  Rear braking better for sure.

Got on the bit ugly silencer with some chrome polish on a 4" felt wheel.  Quite an improvement. 

Slowly whittling down the "to-do" list.   

Need some kinda mirrors, come to think of it.  Tried on a pair of the original type but didn't like the look so removed 'em again...   Any ideas?

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: heloego on April 17, 2018, 02:32:43 pm
Mirrors?  8)
   Best bet is to get on Amazon or E Bay and spend millions of hours perusing the available offerings.
   I finally went with these:

   (https://i.imgur.com/jn1hbzw.jpg)

   Felt they looked more appropriate with my Electra AVL. The C5 has round ones.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 17, 2018, 04:52:35 pm
Mirrors?  I finally went with these:

Thanks, I like those a lot, and I'm sure they'd give a better view than the originals, which on mine sat quite inboard. 

In other news:

Surprisingly I found the breather can duckbill in stock at the shop where I bought / rebuilt the bike.  Wasn't even shown/listed in the exploded catalog diagram.  Parts man there says "throwing oil" is a pretty common problem with AVL's, especially with...eh... foreign riders, who I suppose drive the bikes a bit more spirited / higher rpms than most Indians would.  See photo below for what is apparently the RE part number, if anyone else should need them.

But even the new piece wouldn't seem to function very completely as a non-return valve.  I can just as easily push / suck air through either end - maybe it would close off under sudden, higher-volume vacuum (or when very oily?) but have some doubts - held up to light, it's clear that it's a bit open in its static position. 

Parts guy says that what has worked well on several occasions (incl. with the farang riders) is installing in its place in the can a piece of upright rubber tubing with end blocked, and a fine cut through the side.  Same basic function, but being razor cut rather than molded, might provide a finer, more immediate seal?  Incidentally, this is how tire-tube valves on Indian bicycles work - tiny little length of end-blocked, slit rubber pipe - they'll stay sealed for months apparently, while still passing air in the other direction when it needs to be added - brilliant! 

Anyway, figured that if it was possibly going to be throwing oil out as a regular feature, I'd better at least figure out how to check my oil more reliably.  Now re: my eyes I know I'm nearing the half-century mark, but still, that smooth, round dipstick shaft has seemed about the worst thing in the world for visibility, especially with fresh, quite transparent oil. 

A few minutes with an angle-grinder brought us to the solution below - flattened one side with a rather coarse wheel, then notched with a cutoff wheel.  Maybe still not as good as a crosshatch, but quite legible now:

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: heloego on April 17, 2018, 05:21:20 pm
   Interesting. So your dip stick was completely smooth? Must be an Indian thing.
   My Electra X dip stick is flattened on one side with cross hatching. Still a bit hard to read with fresh oil, but workable.
   (https://i.imgur.com/1NKYelg.jpg)
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 22, 2018, 04:34:01 pm
....a recovering Himalaya Basher.

Recovering, not quite recovered, but on the road... to fuller improvements and inevitably, additional abuses. 

For your viewing pleasure, a few pics taken here locally today, attached down below:

Looks better, turns better, stops better, runs better, and is more comfy besides.  Still a raw, rude, crude old thing of course, but pretty tolerable. 

Got lightly rear-ended a few days back by a car... smashing the std. Bullet taillight (which I always loathed) and bending the heavy number plate - fortunately not the mudguard.  So put in a new aftermarket light that probably weighs a hundred grams vs. maybe a kilo for the original (every bit helps).

Caught up in other work so just riding it for now.  200km's done thus far.  Rings must be seating, because leakdown is minimal and getting the engine to where I need to for kicking is becoming tougher.  Looking for a couple of missing decompressor parts...

Otherwise hoping above all that the crank will hold up.  If all's well, I could probably be riding this for a long time. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: tooseevee on April 22, 2018, 09:36:55 pm
   Interesting. So your dip stick was completely smooth? Must be an Indian thing.
   My Electra X dip stick is flattened on one side with cross hatching. Still a bit hard to read with fresh oil, but workable.
   

            Rub some chalk into the cross-hatching. Instant readableness :) ;)(http://)
Title: Re: First AVL ownership/build... tech questions...
Post by: DanB on April 23, 2018, 01:13:32 am
Quote
For your viewing pleasure, a few pics taken here locally today, attached down below

Looks good to me!! Nice job and enjoy the ride.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 23, 2018, 10:19:18 am
The decompressor on the AVL is a joke.

With a bit of work to the cylinder head you can fit the old-style decompressor off the iron barrel models. Works just fine.

https://forum.classicmotorworks.com/index.php/topic,25254.0.html

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on May 12, 2018, 08:09:05 pm
Re: the original AVL decompressor, I've actually seen a couple that work - at least they work as well as I'd need them to, just something to get me over the compression "hump" before kicking so it's rotated to where it needs to be...  That said I know the CI decomps work better and have seen one AVL here thus converted, but I just don't feel like cutting into my head or especially removing fins. 

Two questions:

1.  Was wondering what can be done about headlight aim on the original style (I guess 7") models without adjustments (I understood from another thread that the DOT mandated adjustability, forcing RE to switch to smaller reflector in the U.S. to allow space for the screws?).  Anyway, I'm continually blinding oncoming traffic on low-beam, and high beam does me no good, being pointed pretty much up in the trees (this is not related to my tyre-size change btw).  Seems a common issue here, but as a great many Indians don't mind blinding one another, and actually seeing where one is going is generally optional, not many complain and thus solutions are not exactly highly sought after / developed on this end. 

2.  Photos below show two different front shock types.  The second one is used on pretty much every Bullet model from long ago till the present.  The first is (curiously) utilized on the domestic-market "Desert Storm" (military-colored) 500CL (UCE) Classic, and so far as I can tell, on nothing else.  All the other 350/500CL models, as well Std. UCE Bullet, CI's, AVL, etc, etc, have the axle mounted forward for an inch or so of rake/offset.  Why the zero rake geometry was used on the D-S only is seriously mysterious, I don't remember the bike being marketed as having a revised suspension or unique intended use or anything.  Can anyone fill me in on what the export models are using, and what the observed / expected effects would be?  I'm assuming quicker turning (which I wouldn't mind actually)? 

thanks again in advance. 

Title: Re: First AVL ownership/build... tech questions...
Post by: Arizoni on May 12, 2018, 10:58:06 pm
The "in line" style of front fork with the axle in line with the center of the tubes is not unusual here in the US. 

Several years ago, Royal Enfield addressed the handling problem we found with the C5 motorcycles by redesigning the front fork.  They also quit supplying the C5 with the smaller, 17 inch (I think) rear rim and changed it to a 19 inch size.

The older C5's handling problem was at high speeds above 60 mph the motorcycle became totally unstable, twitching and moving in unexpected directions.
Needless to say, that was dangerous.
The new "in line" front fork and rear wheel change (and possibly other frame changes that weren't noticeable.) seems to have fixed the problem.

This instability problem was never present on the Electra's which have a different frame than the C5 and the Desert Storm (which is mainly just a different paint job on a C5).
As I recall, the B5 also has a different frame and it never had a problem.

I guess the bottom line is the AVL's don't have a frame like the C5 (and Indian Bullet) so they don't have the instability problem.

By the way, that offset front axle design goes all the way back to 1946, when Royal Enfield first introduced its tubular front fork.
It is one of the characteristics of Royal Enfields that distinguishes them from the BSA, Triumph, and other British middle-weight motorcycles who used the "in line" designs.
Ah!  Traditions !!!
Title: Re: First AVL ownership/build... tech questions...
Post by: mattsz on May 12, 2018, 11:09:10 pm
The older C5's handling problem was at high speeds above 60 mph the motorcycle became totally unstable, twitching and moving in unexpected directions.
Needless to say, that was dangerous.
The new "in line" front fork and rear wheel change (and possibly other frame changes that weren't noticeable.) seems to have fixed the problem.

Interestingly: as I recall, not all of those early C5's demonstrated those stability issues... some never showed any signs of trouble.  Others were very problematic.  No surprise there, I guess...
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on May 13, 2018, 05:49:17 pm
Photo caption: "Why I never have high speed stability issues"... or, "What roads were like when the Bullet was originally conceived / built"; or "My current daily commute"

Well, they're working on "double-laning" the highway that leads up here but still not many straight stretches where 60mph is safe.  Indian consensus is that Bullets are best in every way around 50mph so handling complaints of the nature described would be rare. 

Wider/lower 18" rear and lower-profile 19" front tyres began with the C5 (I guess CL "Classic" here) around 2011, and all domestic RE models (exc. CGT maybe) use them now, partly for looks and partly maybe because it lightens the front wheel a bit and gives a bit better braking traction out back. 

I'd have thought the zero-offset fork would actually lead to quicker response/turning/"twitchiness?" (which I'd prefer up here) rather than being a solution for higher-speed issues.  Because it'd create a shorter wheelbase and something akin to a lesser castor angle I suppose?  Anyone ridden the two types side-by-side who'd be able to comment? 

And what of that headlight???
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on May 13, 2018, 05:57:30 pm
Quote
And what of that headlight???

For purely cosmetic/personal preference reasons I replaced the casquette headlamp on my old Electra-X with an alloy top yoke and 50's style headlamp brackets from Hitchcocks's here in the UK. This also allowed for full headlamp adjustment, as an added bonus.

I think the answer in your situation would be to use the front end parts off a 2004(?) 350 AVL Thunderbird with the separate headlamp, brackets and top yoke for the screw-in fork stanchions, not the later plain type, plus whatever instrument bracket takes your fancy, as you only have a speedometer and no rev-counter to worry about. The instrument bracket off the old Superstar Bullet would do it.

This is the Electra-XS, only seen in the UK, but with a Thunderbird type front end.

(http://www.imageupload.co.uk/images/2018/05/13/DSCN4070.md.jpg) (http://www.imageupload.co.uk/image/E8K2)

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: heloego on May 14, 2018, 01:40:19 pm
Buried somwhere in this forum is a post or 2 or 3 about headlights.IIRC the 7" lamp is available bias toward the left or right, depending on its intended country of destination. IOW which lane is correct for your country, so it aims a bit toward the side of the road, rather than the oncoming traffic.
Is it possible you have an incorrect lamp installed?
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on May 14, 2018, 03:05:02 pm
If I remember correctly India drives on the left, the same as the UK. If it's a home market bike it should have the correct low or dipped beam which should deflect to the left, but if there's insufficient vertical adjustment to adjust the beam for height, i.e. lower it, it will STILL be a nuisance and possible danger to oncoming road users at night, whether or not it's the correct part.

A.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on March 16, 2019, 05:38:05 pm
Wow, it's been ages since I've been around here / posted anything...

The Machismo's fresh engine got pretty well broken-in over the course of last year; Sometime in Autumn I finally had looked into the starter problem and found it was only the solenoid, which costs about $5 here in India.

Later loaned it to a friend whose 500 Classic (C5?) was in for its own rebuild in the midst of some labor/ management upheaval at the local RE showroom... so it ended up being with him a month or two.  He gave it back one evening, quite impressed with its power/smoothness, but two issues had come up:  1.  wouldn't upshift properly.  He'd thought it was a clutch-related issue and the dummies at the showroom had fooled with it a long while, putting a new cable, adjusting / readjusting, etc.  To me it didn't feel like anything a clutch would do, so took off the gearbox side cover and finally found that the self-locking nut on the end of the countershaft had come loose, allowing the shaft to move axially... tightened up (with Locktite), and all's well. 

Secondly, on my friend's watch it had just started this thing of the engine dying whenever the headlamp was switched on.  Ever since I'd bought it it had occasionally blown its fuse (the main one, there's another up under the seat but not sure what if anything it does), and once when I'd run out of spares I "temporarily" direct-wired it... yeah, not a great idea and though it took two months for it to finally happen, I suppose the raging fire in the left sidebox one dark night was predictable.

That was in December and we were away for the remainder of the winter so got back to it yesterday.  Damage not too extensive, did a bit of re-wiring, also re-locating the starter solenoid so I could reclaim the left sidebox for its original intended (or other) use.

That done, got thinking of the right sidebox, which the big air-filter has taken over in later models.  This Indian AVL has lot of convoluted / leak-prone plumbing between it and the carb besides, and I thought it best to just be rid of all of it. 

And while I'm going to that much trouble, may as well swap in the 32mm carb, too.     

Reason I hadn't done that already is that:

1.  The carb was a salvaged piece from a 220cc Indian bike... figured re-jetting/setup was going to consume a lot of time.

2.  It is one of the few electric-choke bikes in India, though the original manual choke plunger is not very ideally located, I really wanted to keep things simple as possible.

3.  It already ran pretty well with the 28mm and gave great fuel mileage, so on of those "if it ain't broke, don't fix it" things. 

Happily / surprisingly, it started right up without the choke (late winter here), idles fine, and seems to run pretty well across the board, plenty responsive for me - so it seems fine-tuning will not be too painful.   

Real-world performance and economy will have to be gauged as time goes on, but I can't imagine but that the former wouldn't be better... the elimination of all that (convoluted) plumbing alone would have to make some positive difference, even without the bigger carb.   

Conversion was painless - throttle cable is on opposite side but same length / adjuster fits the new carb.  Same fuel line works too.  I modded a manifold from a (223cc) Indian Honda.  Could've used a UCE500 piece too, but this one provides more space for the bigger carb/filter as it's angled outward slightly.  Air filter's paper, possibly a little more flow area than OE, but might try and find a foam one for it.  Fitted to carb with a trimmed junkyard piece of radiator hose.  Fab'd the stainless steel shield over it - mainly to keep rainwater off the paper element, as this bike gets parked outside most of the time. 

If I'd known it was gonna be this easy, I'd have done it long ago. 

If I end up needing a functional choke will probably go with the electric setup / handlebar-mounted switch, which in truth would be a little better than groping around behind the fuel petcock all the time.  The electric start seems to make the whole process of getting it going a lot more flexible / forgiving. 

Anyway, happy to have it running again and running well, and also to have a lot more on-board storage space.  Gonna put together a tool/spares kit for one side and keep First-Aid / and maybe a pack of biscuits in the other... :-)

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on March 17, 2019, 08:45:58 am
Empty toolboxes...

Left side has only the main fuse and the lead for the brake switch... which totally fried in the aforementioned side-box fire...

Right box has rat-sized holes leftover from the air-filter function - so not going to be able to leave my emergency biscuits in there...

I was a bit bothered when I saw that the Classics (C5) had a fake air-filter cover on the right... aesthetically spot-on, but... faux. 

In the Machismo's case, nothing "wrong" with putting electrical components or air filters in the boxes, but I figure if I can keep a reasonable stock of essential tools/spares/first-aid/meds/etc in there, it frees me from having to pack up / secure such stuff up elsewhere on the bike before taking off on medium/long-range trips. 

Only downside is that I don't get the potentially torque-enhancing stack-length in the intake plumbing that I'd have liked to experiment with.  That may amply compensated for by having everything a lot freer-flowing. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on March 20, 2019, 10:45:40 am
Factory tool kit is missing and probably wasn't adequate anyway...

So any travelers/tourers who can advise re: the "essential" tool kit for an Electra (Machismo)?  Like to travel light but then again heading to very remote places several hundred km's from home potentially.

My old Kawasaki (KH125 smoker) could be stripped bare and engine completely opened with a shockingly small set; substantial fastener standardization meant mainly 10/12/14mm and one or two 8, 17, 19 (if pulling the flywheel).  And the sparkplug of course.  Wheel removal / chain adj. were managed with the incredible Knipex Cobra pliers (okay, sue me!).  So four or five combi wrenches and as many 3/8"-drive sockets with a little folding ratchet, and a screwdriver w/bit set (which fit inside the handle!), and I was good to go.   

But Enfields seem to use about every size under the sun, including a few leftover Whitworth in some choice spots... not to mention the special tools for pulling the clutch, etc.

It's obviously not going to be feasible roadside to split cases or dig too far into the gearbox, and I'm pretty in-tune with wear items like clutch, so assuming I'm not going too deep, what all is useful for basic adjustments / cable changes / tightening loosened stuff, etc?  I suppose I'd carry a spare stator / coil with me, though they're not supposed to be that failure-prone.  Can manage the carb easily enough.  Any realistic way to put together a compact kit for longer (500+km) tours on rough tracks?  As per previous post, it's all gotta fit in a side-box. 

Thus far figuring:

1) (the usual) Knipex, Leatherman Wave and Victorinox mini-Champ trio (with which I have managed an astonishing amount of work in a pinch);

2) the sparkplug tool (obviously); 

3) A few Allen(hex) keys - for the clutch housing / clutch cable-end cap, the stator, and (big one) for the steering head adjustment. 

4) Test-light / mini-meter will be there.

5) I've got my tube-patches, a little sparkplug-port adapter tyre inflator, and pair of shorty tyre-irons. 

6) Could get the special bit-set for the Wave or else an adapter so it'll take standard 1/4" screwdriver bits and 1/4' drive sockets, or else stick with the usual 3/8-drive.

7) I suppose something for the valve adjustments would be useful.

Trying to avoid drawing from my regular set, these will stay with the bike full-time, harder each time to forget things that way.   


So what am I missing (and what typically vibrates loose on these bikes)?  It's the bigger sizes that are heavy/space-consuming, of course, so looking for creative/efficient solutions for those (wherever the Knipex won't work!). 

The tour-company guy I bought it from always had a support vehicle along so compactness of kit wasn't an issue.  And most other Indians just take off without a care in the world, can't change a fuse much less a tyre or anything mechanical, they load the bikes in a truck and send it onwards/back to the nearest mechanic if anything "unexpected" happens. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: tooseevee on March 20, 2019, 12:01:40 pm
But Enfields seem to use about every size under the sun, including a few leftover Whitworth in some choice spots... not to mention the special tools for pulling the clutch, etc.

-Eric

            I found that on my '08 Classic also. All three sizes were found and a few that no socket, box or open end seemed to fit perfectly. It's all just part of the Royal Enfield game :) :)

            You mentioned the dipstick elsewhere: I rub chalk into the cross-hatching on the dipstick. Makes it very easy to read. (Chalk for blackboards. Remember blackboards ???(http://[img])[/img] ).

             The AVL engines will blow out any excess oil. They have a hissy-fit if over-filled  :) ;)(http://)
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 02, 2019, 09:25:06 am
Well, on account of the "database error" can't write everything here I wanted to - maybe that's a good thing!

In short, I had put about 2,000km's on the bike since building it last spring, and with the new carb/filter was enjoying what seemed a bit enhanced mid/upper range power... and a hard uphill, somewhat higher rpm run one day left me with nasty noises coming from the crankcase... not a knock, sounds more like a bad/rough main bearing.  I outlined above concerns I had about how they'd built the crankshaft, but other thing is I put standard-clearance NRB main bearings in it; recently another Brit up in these hills who's hoarded something like twenty Bullets is telling me the NBC's/NRB's used by RE and typically used for rebuilds in India are the cheapest options with corresponding reliability.  So I'll have to open it again, we'll see what's gone wrong. 

1.  ACE/Adrian/BW/other engine guys: How important do you think the C3 spec would be on the main bearings?  A lot of bikes (incl. my Kawasaki) do specify them for the crank - did RE ever?  Seems wise considering our heavy-load hill conditions / short runs / RE's poor machining tolerances (thinking of case misalignments, and I can see uneven wear on the old main bearing races, though it didn't cause any failure in six years).  I can get the Japanese NTN's here (NU205/305) but thus far haven't found them in C3.  Stated otherwise, if it came down to Indian C3's or Japan/Euro standard fit, what would be the better option?  Are Hitchcock's UK-bearings standard or C3? 

Also (ACE), finally found your old breather thread  https://forum.classicmotorworks.com/index.php/topic,4802.45.html (https://forum.classicmotorworks.com/index.php/topic,4802.45.html) wherein you stated it wouldn't work on AVL's due to the lack of the crank seal on the timing side, which in the new low-pressure environment would lead to wet-sumping. 

Now here's the thing: A new senior mechanic showed up here a few days back who apparently used to work at the Chennai RE factory (and independently later), who seems familiar with all the typical AVL weaknesses / mods (incl. CI tappets/spindles/cam conversion, etc).  He says he adds a seal there by re-purposing the (felt?) one from the old point-ignition distributor - presumably kind of squishes it in between the case and the oil-pump drive gear.  Sounds like a classical case of Indian "juggad" but sometimes these things do actually work.  Also says that if I let him build the engine he'll give me a 5-year, unlimited mileage guarantee (why does this sound familiar???!!!). 

Anyway, if the felt(?) were sufficiently saturated with oil and snug in there, and moreover held against the crankcase side by whatever light vacuum is in there, could it be enough to keep excessive oil from moving past into the crankcase... and is the benefit of the relocated breather worth any associated risk of this NOT working?  Machining for the old-model crank seal won't be feasible in this context (don't know anyone with a milling machine), whereas drilling for the engine-side breather and doing the crescent in the case with my die-grinder would probably be pretty do-able.  And on the AVL I still do have to block off the 3mm hold between the crankcase and oil tank, right?  In my case I'd want to retain the catch-can (don't want the rear-exit, it's just too dusty here and it's all going to stick to any oil-spatter/mist), so if the crank/oil tank are again separated, I guess I could drain it back into the latter via the original nipple there, correct?  Or else the timing-case, which does have a duckbill inside already. 

2. Hitchcock's $50 crankpin is the Indian one, no specs available, so no advantage.  Their U.K. made one comes only in the complete, fitted rod kit, which is well beyond my budget... So I'll just get the RE pin over here, a friend up here has 50,000km's on his crank (on a stock C5), and that's a combination of daily short hill runs (7km's commute), and a fair amount of mountain touring with pillion and luggage. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 03, 2019, 11:46:06 am
C3 is very I.important.

You could try the felt seal.

Keeping the catch can is okay.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 03, 2019, 04:03:21 pm
You could go down the Rube Goldberg/Heath Robinson route with your breather set-up.

(https://i.ibb.co/JC6Zvsw/DSCN7030.jpg) (https://ibb.co/mSZp9cV)

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 03, 2019, 08:22:08 pm
Well, the supplier found the NTN NU305 in C3, but not the NU205 (timing side).  Unless I want an SKF C3 with a nylon cage... which I'm assuming is not acceptable in this application.  Right? 

Ace, does the C3 spec hold for the outboard 6305 ball bearing too, the one nearest the primary chain?  So far only available in India-made if I want C3, probably FAG.

Secondly, if this felt-seal idea didn't work and I've already blocked the orifice between tank & crankcase and converted to the old setup, what's the worst that could happen?  I'm assuming wet-sumping is not good, but will it blow up my engine, or??? 

Trying to work out a risk/benefit analysis here...

Adrian, a good chuckle before bed is just what I needed.  That setup is just... beautiful...


Thanks to you both,
Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 03, 2019, 10:05:13 pm
I usually use a C4 for the 6305, but a C3 will work.

If you can get GENUINE FAG X-Life brass caged NU205-C3 and NU305-C3 made in India, that is okay. All the FAG X-Life bearings are made in India. The critical factor is that they cannot be fakes. They must be the real thing.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 03, 2019, 11:06:22 pm
I have a set of 500 Iron Barrel cases with the breather stub drilled out by the factory, and it's not that big a hole, so if you do go down this route and plug the small hole through the crankcase wall, I doubt it will make much difference. Using your own threaded pipe union as I described might allow the crankcase to breathe slightly more easily depending on its internal bore.

The 3" drip-feed oiler as catch-can was a good laugh - it got some good WTF? reactions, and I had a Hellman's label taped to it for a while. However, I found it leaked badly after a while and the acrylic "glass" went opaque with a chemical reaction to the oil/crankcase gases, so it's off the bike at the moment. I now have a proper glass for it and some decent gaskets, so it might go back on.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 04, 2019, 06:21:41 am
On my AVL hybrid I used the longer exhaust pushrod in place of the inlet pushrod, and screwed in a late iron barrel tappet adjuster which used the same 6mm thread as the AVL version. For the exhaust I used the exhaust push rod and tappet adjuster from a 500 iron barrel engine, I made a bronze bush and fitted it to the top of the alloy section of the rod and pressed the top of the old inlet AVL pushrod into that. This means I have one metric and one imperial tappet adjuster, but nothing I can't live with!

The point of replacing the AVL cams with the "S" is that the originals have been found to cause valve bounce at 5,800 RPM, they can be used with the original tappets/followers, though, if you slacken off the tappet adjusters enough.

I'm thinking to stick with the original AVL cams since they seem fine for low/midrange which is mainly where I'm at.  Probably good for fuel economy, as well, and I've been happy with the performance.

But for reliability would like to do the CI tappet conversion.

So if I've got the original AVL cams, is it likely that the original pushrods would basically work if the late-model CI adjusters are screwed into the bottom to mate with the CI tappets?  Keeping in mind that my cylinder is 2.5mm shorter than stock. 

Trying to not get too heavily into custom machining too many items, since here locally nobody's even got a full set of drills, never mind thread taps; and being that the bike could eventually end up in someone else's hands, preferring not to make it too hard for anyone to figure out later. 

-Eric

Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 04, 2019, 03:20:33 pm
From memory I think the length of the AVL and C.I. tappets themselves is about the same, I will see what I can find in the garage and check. "S" cams and C.I. Indian Bullet cams have a smaller diameter base circle than the AVL, so the AVL tappets will sit higher.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 04, 2019, 03:54:45 pm
If it is close, you can grind the pushrod adjuster locknut thinner. I have done that a time or two when it was close to fitting.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 09, 2019, 06:24:20 am
Okay, so my supplier finally found both NTN C3 mains and imported big-end needle... 6305 primary side will be C3 in Indian FAG, which is probably fine.  Ordering them up and probably dig into it next week. 

On the tappets (again):

Had a photo posted here earlier of the CI/AVL's tappets/guides side-by-side.  So here's the concern: The weight of the CI tappet itself is a LOT more in view of its increased stem diameter.  If using stock AVL cams, is that going to get me into even more trouble than stock as it concerns valve-float?  I'm going to venture a guess that AVL's engineers reduced the stem diameter specifically for this reason, to reduce weight, knowing they had cams with sharp ramps / profiles that would tend towards float... (???)

I don't plan on doing a lot of high revs and if I lost power to float there it wouldn't really matter -

BUT: Could this extra weight /float increase my chances of valve/piston contact (and thereby get me back in a realm of unreliability I was trying to correct)? 

If my brain's working right, I guess the risk would be more on the exhaust side: As the piston moves up to vent gases, the exhaust cam is on its downramp and valve correspondingly closing... piston "chasing" the valve then, and if the valve closing were delayed on account of float, then what...???  Intake wouldn't matter since IIUC piston is moving down as valve opening approaches its maximum. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 09, 2019, 08:01:32 pm
Not sure. When I tried a set of cast iron (indian) Bullet cams in my Electra-X it was the inlet valve head that made contact (just) with the piston crown. That was with the timing on the dots. Using the trick of retarding the cam gear one tooth mightr have prevented that.

According to Bullet Whisperer valve bounce with the AVL cam sets in around 5800 rpm, would you normally want to rev it that far? I suppose the alternative would be to have a set of tappets made to the AVL dimensions but with some tougher grade of steel, carefully heat treated and possibly with the flat faces stellite faced?

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 09, 2019, 09:48:40 pm
CI Bullet cams lift about .030" more at the lobe than AVL cams. So, if you then multiply by whatever rocker ratio happens to be in your AVL, which might likely be around 2.2, then you can see that it may get into contact with the piston after doing the squish mod.

I am more optimistic that stock AVL cams would be less likely to make contact with the piston, but it should be checked.

While I am generally in favor of retarding the inlet cam, my old measurements indicated that the AVL stock cams were already retarded pretty well, and would not need much more retarding. I would take a look at possibly using an offset Woodruff key to get just a few degrees more retarding if you need it. A whole tooth retarding is a lot for an AVL, in my opinion.

Maybe a little retarding by a few degrees along with a little valve relief in the piston crown might be the ticket If you get contact or insufficient clearance.

ALWAYS do a check of your valve timing and clearances when fiddling around in this area.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 10, 2019, 04:12:36 am
According to Bullet Whisperer valve bounce with the AVL cam sets in around 5800 rpm, would you normally want to rev it that far? I suppose the alternative would be to have a set of tappets made to the AVL dimensions but with some tougher grade of steel, carefully heat treated and possibly with the flat faces stellite faced?

Adrian, so you still have the AVL cams, and the CI tappets?  If you're not having problems with premature float, then probably I won't either.  Unless you've also got stiffer aftermarket valve springs. 

I won't often/ever see 5,800rpm, but I was more concerned that the CI tappets' extra weight (inertia) could create the float at even lower rpm : Suppose it happened at 5,000... and if that float put me at risk of valve/piston contact...

Getting tappets made here would be next to impossible.  I do wonder though whether the weakness was in "all" AVL tappets or only some of them... A mechanic for this fleet said they very seldom have seen them break, but I've seen three such cases locally with my own eyes, and you've seen a couple, so I don't feel very confident about them. 

I am more optimistic that stock AVL cams would be less likely to make contact with the piston, but it should be checked.

While I am generally in favor of retarding the inlet cam, my old measurements indicated that the AVL stock cams were already retarded pretty well... A whole tooth retarding is a lot for an AVL, in my opinion.

Maybe a little retarding by a few degrees along with a little valve relief in the piston crown might be the ticket If you get contact or insufficient clearance.

ALWAYS do a check of your valve timing and clearances when fiddling around in this area.

I experimented with retarding a tooth last year, and while it killed my low-end, it also did nothing at all for the mid/top. 

But I suppose the final question is how much clearance is "sufficient"?  Since we don't really know when float would occur with the heavier CI tappets / stock AVL cams & valvesprings, the clearance spec for other setups may not be appropriate; And I can only measure it statically - Knowing what it's doing at 5,000+rpms is the tricky (and critical) part.  But I suppose a little extra relief on the crown would be the best insurance, it's easy enough to do. 


On another note, I also was able to source the big-end needle bearing with hardened outer race, as per Hitchcock's kit.  Basically it's got the same needles, the race adds 3mm to the OD (making it 45mm), for which the rod would have to be machined.  I'd like to try that, theoretically it could probably be done straight / accurate on a CNC boring machine (which we have here not too far away) - but the trouble is the existing heat-treating of the rod's big-end, which would make it too hard for standard cutting tools to manage, I'd assume.  What I'd gain would be the ability to use the old-style rods w/ small-end bush, while having a 58-62hrc outer race on the big end for the needles to run on, in the process also giving me a fully rebuildable rod.  Just not sure whether it's machinable as is.  Would I have to use an ID grinder (good luck finding that here).  Or maybe have to "anneal" it?  And if messing with heat does that get me into all sorts of other trouble with straightness, etc?  Might be getting in over my head here...

-Eric

Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 10, 2019, 02:09:16 pm
Adrian, so you still have the AVL cams, and the CI tappets?  If you're not having problems with premature float, then probably I won't either.  Unless you've also got stiffer aftermarket valve springs. 

I won't often/ever see 5,800rpm, but I was more concerned that the CI tappets' extra weight (inertia) could create the float at even lower rpm : Suppose it happened at 5,000... and if that float put me at risk of valve/piston contact...

Getting tappets made here would be next to impossible.  I do wonder though whether the weakness was in "all" AVL tappets or only some of them... A mechanic for this fleet said they very seldom have seen them break, but I've seen three such cases locally with my own eyes, and you've seen a couple, so I don't feel very confident about them. 

I experimented with retarding a tooth last year, and while it killed my low-end, it also did nothing at all for the mid/top. 

But I suppose the final question is how much clearance is "sufficient"?  Since we don't really know when float would occur with the heavier CI tappets / stock AVL cams & valvesprings, the clearance spec for other setups may not be appropriate; And I can only measure it statically - Knowing what it's doing at 5,000+rpms is the tricky (and critical) part.  But I suppose a little extra relief on the crown would be the best insurance, it's easy enough to do. 


On another note, I also was able to source the big-end needle bearing with hardened outer race, as per Hitchcock's kit.  Basically it's got the same needles, the race adds 3mm to the OD (making it 45mm), for which the rod would have to be machined.  I'd like to try that, theoretically it could probably be done straight / accurate on a CNC boring machine (which we have here not too far away) - but the trouble is the existing heat-treating of the rod's big-end, which would make it too hard for standard cutting tools to manage, I'd assume.  What I'd gain would be the ability to use the old-style rods w/ small-end bush, while having a 58-62hrc outer race on the big end for the needles to run on, in the process also giving me a fully rebuildable rod.  Just not sure whether it's machinable as is.  Would I have to use an ID grinder (good luck finding that here).  Or maybe have to "anneal" it?  And if messing with heat does that get me into all sorts of other trouble with straightness, etc?  Might be getting in over my head here...

-Eric

Safety margin for piston/valve clearance is .060" for inlet valve, and .100" for exhaust valve

Just buy the complete rod and bearing assembled from Hitchcock.

Don't be concerned about tappet weight. It won't matter.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 10, 2019, 10:51:52 pm
Quote
Adrian, so you still have the AVL cams, and the CI tappets?

Not in the same engine! I have used C.I. cams with AVL tappets but never the other way round.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 10, 2019, 11:06:40 pm
If the CI and AVL tappets have the same foot diameter, either type will work fine.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 11, 2019, 05:58:22 pm
If the CI and AVL tappets have the same foot diameter, either type will work fine.

Yes, they do, and I'll be doing the mod, thanks for your inputs. 

Now here's something: I've had 2-3 mechanics tell me recently (and curiously), that the AVL valvetrain tends to wear prematurely - incl. cams / cam gears, and spindles - that you put all new ones in and within a year or two they're getting loose / noisy again; They recommended changing everything over to the CI pieces just for the sake of durability.  Odd... I just can't imagine why this would be.  Is there a difference in the oiling system they don't understand, or could the materials for some odd reason actually be worse in the newer design, or again could the sharper ramp-up (shorter duration) of the AVL cams be putting more load on everything?   

Debating whether to take their advice.  Basanti said the CI cams were way better for speed.  I'm mainly after low/mid and fuel economy, but do want sufficient durability to be able to build it and more or less forget it for several years... that's where the above question comes in.

Anyone venture an explanation for allegedly longer valvetrain life in CI's?

On FE, one mechanic assured me there was no difference after changing to CI cams... but I really wonder, being that the duration / overlap would be more, and that stock CI's got about 20-25kmpl up here, and the AVL's/UCE's manage more like 30. 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 11, 2019, 07:42:05 pm
Quote
stock CI's got about 20-25kmpl up here, and the AVL's/UCE's manage more like 30

Nothing to do with the AVL's CV carb, then?

Whatever faults have arisen in the UK concerning the Electra-X nobody seems to have mentioned premature valve train wear. For the C.I models Samrat used to offer super-thick stem tappets in bronze guides (my AVL hybrid has a set, but sadly Hitchcocks' have long been out of stock). Maybe see if you can find a set.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 11, 2019, 10:55:38 pm
Yes, they do, and I'll be doing the mod, thanks for your inputs. 

Now here's something: I've had 2-3 mechanics tell me recently (and curiously), that the AVL valvetrain tends to wear prematurely - incl. cams / cam gears, and spindles - that you put all new ones in and within a year or two they're getting loose / noisy again; They recommended changing everything over to the CI pieces just for the sake of durability.  Odd... I just can't imagine why this would be.  Is there a difference in the oiling system they don't understand, or could the materials for some odd reason actually be worse in the newer design, or again could the sharper ramp-up (shorter duration) of the AVL cams be putting more load on everything?   

Debating whether to take their advice.  Basanti said the CI cams were way better for speed.  I'm mainly after low/mid and fuel economy, but do want sufficient durability to be able to build it and more or less forget it for several years... that's where the above question comes in.

Anyone venture an explanation for allegedly longer valvetrain life in CI's?

On FE, one mechanic assured me there was no difference after changing to CI cams... but I really wonder, being that the duration / overlap would be more, and that stock CI's got about 20-25kmpl up here, and the AVL's/UCE's manage more like 30. 

-Eric
There is no reason for any difference in valve train life, except the AVL has a small rocker ratio, and the CI doesn't.

The main thing between CI and AVL tappets is the valve lifter system on the AVL tappets vs the regular decompressor of the CI. It may affect the valve lifter fit.

I don't really know how to put this diplomatically, but it would be best to not listen to these "mechanics" that you seem to be consulting.
There seems to be a lot of BS floating around mechanic shops in India.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 12, 2019, 12:23:15 pm
You can actually have the AVL-style valve lifter on a C.I. Bullet if you really want one.

http://accessories.hitchcocksmotorcycles.com/accessory-shop/Valve-Lifter?&model=

I don't know if they have sold many.

A.

Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 12, 2019, 07:16:33 pm
The thing about Indian mechanics is that they have no clue about theory most of the time, they operate on very strange assumptions sometimes, and surprisingly often (not always), it "works" despite the spurious bases.  Kinda like some elaborate systems of pre-Galilean astronomy... Wrong assumptions but kinda worked as a system.  What I've found is that what these guys lack in basic understanding / book knowledge they sometimes make up for by doing/ seeing every single thing just thousands and thousands of times over, and learning bit by bit what works and what doesn't.  I mean, as one example, they've been clear as anyone here about the weakness in the tappets, and worked out the same solution as people here did, too.  Independently.  My friend was telling me a few days ago how he saw a pristine paint-job being applied at an outdoor parking lot somewhere in the heart of Delhi - this was on an Audi A8 (!), and there was a lot of other high-end machinery all around, too... they certainly don't play by "the" rules, and many of us in the West find this highly irritating... But the average street-mechanic here probably builds more Bullet engines in a year than most U.K.-based specialists would in ten years.  For those who take pride in their work, there's been a lot of knowledge gleaned / applied.  Somehow they keep more Bullets (and other motor vehicles) going than practically any nation on earth. 


Well, I opened the engine today.  You'd have to go back to post#60 for reference re: why. 

Anyway, turned out to be the timing-side main bearing, the small one.

Possibly was a low-quality bearing, the race was toasted and rollers fine.  But almost certainly a contributing factor was the cam spindle.  No time to post a pic right now, but basically the flat on the flange which is supposed to keep it locked against rotating in the case just doesn't match the case very well, there's a big gap - typical crap machining I suppose.  Meaning that the spindle can probably rotate at least 15 degrees in there if the press-fit were a tad loose, which one of mine was.  Wouldn't be a problem with solid spindles (Adrian's choice here was a good one), but with the eccentrics, the trouble is that when you tighten the locknut backlash may be fine, but if in tightening it the whole spindle rotated clockwise in the case, and later at high revs it rotates back anti-clockwise, then all the lash can be gone.  The exhaust cam in this case was so tight I could hardly pry it out.  Which is NOT how I had set it last time.  There's a way to do the adjusting that would mitigate this risk (tighten the eccentric up against the rotation direction, so that if it rotates back, it can only loosen), but somehow I didn't do it that way.  So here we are.  There must have been a lot of radial load on that end of the crank.

The rod big-end seems absolutely fine, so am debating what to do now.  I kinda figure each time you take a crank apart and reassemble, the press-fits get a tad looser, which of course would create its own problems. 

So the hack who did the crank down in Delhi wasn't to blame after all.  He might've done tens of thousands of these (father did it too, he said at the peak they were doing ten per day - that's 3,000 per year, people), and yeah, he got mine to .0015" runout by eyeballing it with a piece of wire (insane).  And he says I'll get at least 30,000km's out of this.  I think he used NRB needles.  Hmmm... 

As mentioned earlier, just no budget for Hitchcock's rod kit, so is it worth tearing it down just to put a fresh pin / rod / Japan bearing in it (or experiment with my own version of Hitchcock's approach), or should I just re-check trueness and throw it back together with good quality mains (and better tappets, and do something about those spindles)?     

Hmmm...

On another note, is there some procedure for setting up the meshing / distance between the crankshaft worm gear and the mating teeth on the oil-pump shaft?  I put a new shaft in 2,000km's ago and it's looking pretty bad already.  Maybe I didn't put a new worm in, can't remember, but it too looks damaged.  I need to check the parts book and see if there's supposed to be a lock-washer or shim or something between the cam pinion gear and the oil-pump worm gear, mine didn't have any.  It seems to me the worm may be running too far inboard, such that only the outermost part of the worm is contacting the shaft's gears.  Any failures here would seem necessarily catastrophic.   

I guess I could just test-assemble with varying thicknesses of washers in between the two, till there's just a little clearance between the worm and the oil seal?  Left-side crankshaft thrust washer would also have an effect on this I suppose (I have the standard size on both sides)? 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 13, 2019, 01:45:26 pm
Quote
or should I just re-check trueness and throw it back together with good quality mains (and better tappets, and do something about those spindles)? 
   

Yes. Add a good sump magnet as protection for the scavenge oil pump chamber and the rocker feed. Note that if you're fitting plain cam spindles the timing cover's spindle housings will need boring/reaming out to 5/8" to fit. Plain spindles are available in over-sizes to fit worn holes in the crankcase.

Quote
On another note, is there some procedure for setting up the meshing / distance between the crankshaft worm gear and the mating teeth on the oil-pump shaft?  I put a new shaft in 2,000km's ago and it's looking pretty bad already.

I have been caught out like this on my AVL hybrid motor. Some of the worm drives are larger diameter than others. I was also finding bad premature wear on the oil pump spindle gears AND worm gears. What you need is to find the type with the bonded-in rubber seal as these are 0.050" smaller O/D and will give you the extra clearance, you just need to scrape/burn the bonded rubber out to get the thing to fit the end of the AVL crankshaft.

There is also a modification carried out by Tollgate Classics in the UK to fit a 3mm wider crankshaft roller bearing on the timing side, usually for 624 conversions of the 500 C.I. engines!

A.

Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 13, 2019, 03:39:53 pm
The thing about Indian mechanics is that they have no clue about theory most of the time, they operate on very strange assumptions sometimes, and surprisingly often (not always), it "works" despite the spurious bases.  Kinda like some elaborate systems of pre-Galilean astronomy... Wrong assumptions but kinda worked as a system.  What I've found is that what these guys lack in basic understanding / book knowledge they sometimes make up for by doing/ seeing every single thing just thousands and thousands of times over, and learning bit by bit what works and what doesn't.  I mean, as one example, they've been clear as anyone here about the weakness in the tappets, and worked out the same solution as people here did, too.  Independently.  My friend was telling me a few days ago how he saw a pristine paint-job being applied at an outdoor parking lot somewhere in the heart of Delhi - this was on an Audi A8 (!), and there was a lot of other high-end machinery all around, too... they certainly don't play by "the" rules, and many of us in the West find this highly irritating... But the average street-mechanic here probably builds more Bullet engines in a year than most U.K.-based specialists would in ten years.  For those who take pride in their work, there's been a lot of knowledge gleaned / applied.  Somehow they keep more Bullets (and other motor vehicles) going than practically any nation on earth. 


Well, I opened the engine today.  You'd have to go back to post#60 for reference re: why. 

Anyway, turned out to be the timing-side main bearing, the small one.

Possibly was a low-quality bearing, the race was toasted and rollers fine.  But almost certainly a contributing factor was the cam spindle.  No time to post a pic right now, but basically the flat on the flange which is supposed to keep it locked against rotating in the case just doesn't match the case very well, there's a big gap - typical crap machining I suppose.  Meaning that the spindle can probably rotate at least 15 degrees in there if the press-fit were a tad loose, which one of mine was.  Wouldn't be a problem with solid spindles (Adrian's choice here was a good one), but with the eccentrics, the trouble is that when you tighten the locknut backlash may be fine, but if in tightening it the whole spindle rotated clockwise in the case, and later at high revs it rotates back anti-clockwise, then all the lash can be gone.  The exhaust cam in this case was so tight I could hardly pry it out.  Which is NOT how I had set it last time.  There's a way to do the adjusting that would mitigate this risk (tighten the eccentric up against the rotation direction, so that if it rotates back, it can only loosen), but somehow I didn't do it that way.  So here we are.  There must have been a lot of radial load on that end of the crank.

The rod big-end seems absolutely fine, so am debating what to do now.  I kinda figure each time you take a crank apart and reassemble, the press-fits get a tad looser, which of course would create its own problems. 

So the hack who did the crank down in Delhi wasn't to blame after all.  He might've done tens of thousands of these (father did it too, he said at the peak they were doing ten per day - that's 3,000 per year, people), and yeah, he got mine to .0015" runout by eyeballing it with a piece of wire (insane).  And he says I'll get at least 30,000km's out of this.  I think he used NRB needles.  Hmmm... 

As mentioned earlier, just no budget for Hitchcock's rod kit, so is it worth tearing it down just to put a fresh pin / rod / Japan bearing in it (or experiment with my own version of Hitchcock's approach), or should I just re-check trueness and throw it back together with good quality mains (and better tappets, and do something about those spindles)?     

Hmmm...

On another note, is there some procedure for setting up the meshing / distance between the crankshaft worm gear and the mating teeth on the oil-pump shaft?  I put a new shaft in 2,000km's ago and it's looking pretty bad already.  Maybe I didn't put a new worm in, can't remember, but it too looks damaged.  I need to check the parts book and see if there's supposed to be a lock-washer or shim or something between the cam pinion gear and the oil-pump worm gear, mine didn't have any.  It seems to me the worm may be running too far inboard, such that only the outermost part of the worm is contacting the shaft's gears.  Any failures here would seem necessarily catastrophic.   

I guess I could just test-assemble with varying thicknesses of washers in between the two, till there's just a little clearance between the worm and the oil seal?  Left-side crankshaft thrust washer would also have an effect on this I suppose (I have the standard size on both sides)? 

-Eric

The oil pump drive spindle gear meshing is set with the thickness of the timing cover gasket. There are different thickness gaskets available.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 15, 2019, 05:41:00 pm
   
Add a good sump magnet as protection for the scavenge oil pump chamber and the rocker feed.

Can anyone refer me to a good oil-circuit diagram or description?  I guess this is what they'd call a dry-sump system? I'd worked on cars and two-strokes till now mostly, so never really studied / understood them (nor these three drain plugs).  But am wanting to make sure all's well with the supply to that timing-side bearing.  Also if any enhancements are possible would happily take the time to do them now.

I'll try and get some pics up soon.  Bit curious about this "crescent" that was supposed to be machined into early-vent-system cases.  Mine doesn't have it, but there seems to be quite a lot of empty space in the case casting outside the cylinder sleeve, am thinking I wouldn't need any additional machining.  Oh, and the hole between oil tank and crankcase is a pretty decent size, maybe 8mm? 

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 15, 2019, 10:01:12 pm
Main bearing lubrication is splash-feed, where the oil coming out of the con-rod big end bearing is slung around inside the crankcase, and drips on to the main bearings. Same thing on the 6305. All splash.

If you are feeding oil to the crank, you are also splashing the bearings.

The timing side bearing is the small one with the lowest load rating. If you want a stronger one, you can use a NU 2205 which is 3mm wider. Bearing boss in the case needs to be machined 3mm deeper. Oil drip holes above the bearing boss also need to be deepened accordingly by drilling. I have not done this on an AVL case, but we did it many times in CI cases. You should check the casting for room, or maybe Adrian knows if it can fit there.

The CI hole between oil tank and crankcase is only 3mm. The AVL 8mm hole is because they deleted the crankcase vent on the side, and used the 8mm hole to the oil tank instead.
If I were restoring that to CI specs, I would plug that 8mm hole and re-drill it to 3mm when I added the side crankcase vent system.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 22, 2019, 07:36:59 am
Main bearing lubrication is splash-feed, where the oil coming out of the con-rod big end bearing is slung around inside the crankcase, and drips on to the main bearings.

The timing side bearing is the small one with the lowest load rating. If you want a stronger one, you can use a NU 2205 which is 3mm wider. Bearing boss in the case needs to be machined 3mm deeper... we did it many times in CI cases.

The CI hole between oil tank and crankcase is only 3mm. If I were restoring that [AVL] to CI specs, I would plug that 8mm hole and re-drill it to 3mm when I added the side crankcase vent system.

You've all been extremely helpful, thank you again. 

1.  So are you saying that with the 3mm hole, the aforementioned lack of the timing-side crankcase seal wouldn't be an issue?  Also, any problem retaining the catch-can with this kind of setup (huge amount of dust here isn't going to get along well with continual oil mist out the back)?

2.  (See photos below): With all the dependence on oil splashing around, is there benefit in opening up a bit larger "catch" relief / oil hole in the timing-side casting above the bearing, or otherwise modifying it?  Looks like only so much oil would stream down the inside of the case and find its way into that little recess... I have a mind to make it a little more "funnel" like, perhaps?  And/or maybe to enlarge the entire length of the hole that goes down from there to the bearing.  Anyone done anything to improve it?

3.  When you were machining the deepened bearing recess for the NU2205, was it done on a lathe? (no vertical mills around here, but a bit lathe with a 4-jaw chuck)

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 22, 2019, 10:15:57 pm
My advice would be to obtain a set of CI cases and inspect them closely, and try to duplicate the engine breather and small hole to the oil tank as well as you can.

The lack of oil seal on the crank is not obviated. Trying the felt seal might help.

It is unlikely that there is a big enough lathe there to chuck the crankcase and center it to the bearing seat, but if you can, it could be done like that.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 22, 2019, 11:14:26 pm
Quote
Can anyone refer me to a good oil-circuit diagram or description?

From the service manual.

(http://www.royalenfieldlesite.fr/spip/IMG/jpg/02-22.jpg)

You can see all of the manual here:

http://www.royalenfieldlesite.fr/spip/spip.php?article392

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 27, 2019, 03:05:48 pm
The lack of oil seal on the crank is not obviated. Trying the felt seal might help.... It is unlikely that there is a big enough lathe there to chuck the crankcase and center it to the bearing seat, but if you can, it could be done like that.

Well, we've locally got a big enough lathe alright, at least 1-1/2 ft of swing... though its accuracy (or lack thereof) is another issue entirely...!  What a time I had trying to turn down the CI tappet guides!  The big chuck won't grasp anything that small, so had to secure a little three-jaw in that enormous four-jaw... that in itself a workable setup perhaps, but before being forced to painstakingly re-align the whole headstock to the ways, I originally had .005" taper in about an inch-long cut - he says the machine's been like that from new (five years or more???)!!!  Ah, the pains!  He was formerly employed by a certain ex-pat Australian inventor with considerably higher standards... Don't get me started...

Well, here's another:  The second lathe guy an hour from here who told me to expect 100,000km's service if he'd do my crank (he has no dial-indicators, mind you), on whose machine I was trying to fine-tune my crank straightness (with my own set of indicators!), said I needed to tweak it the opposite of what I'd just told him, and in a moment of personal brain-lapse I let him mislead me, he put the thing in his hydraulic press for a little squeeze, and ended up at .010" runout.  I finally got it back within .0008" (.02mm) but would that initial error have enlarged/damaged the holes in my counterweights???  Ah, the pains!!! (this is all very cathartic!).

A third machinist (things do tend to be a little compartmentalized here in India!) was entrusted with the job of installing a threaded insert where my front drain-plug had been cross-threaded.  He managed that reasonably well, but in the process clamped my engine case nice and tight in his knurled, iron-jawed vice and (obviously) marred the gasket surface... well, he charged $3 for his services and thank God for RTV, but really, this is becoming ridiculous.  There is a very good reason that bikes with unopened engines are strongly preferred purchases in India.

If it seemed feasible to set up a complete personal machine shop so that I could get this ONE engine built right, I'd do it...

From the service manual.

That's a great diagram, thanks.  It's a curious system in that the timing case is filled with oil both from the Feed pump (via the spindles) and the Scavenge pump (via the upper valvetrain).  Interestingly then, it seems one could increase flow to the crank by restricting the flow to the spindles a bit... at least to the point where the scavenge pump could handle the extra flow in the crankcase.  IIRC there was a way to do this on small-block Chevrolet's - oil-galley plugs with smaller orifices that held back a little lube from the camshaft in favor of the mains/rods.  In the case of Bullets, correspondingly decreased flow to the spindles/cams wouldn't seem to matter much since ultimately everything runs fully immersed in oil anyway.  Especially if using the cast-iron cams that I see have oil-supply holes at their midline. 

Which brings me to this: I don't fully understand how the AVL spindles were supposed to be lubed.  The spindles are hollow and you'd think the oil was supposed to flow from the timing cover recesses under pressure through spindles and out through the hole at midpoint in the eccentric sleeve the cam runs on...

BUT pressure there is impossible since the spindle ends (locknuts in this case) don't actually seal in the timing cover, which in fact has a long parallel groove in the spindle recesses that would prevent any pressure building, PLUS the flatted locknuts that would actually constitute the oil's path of least resistance; So most oil would just dump into the timing case as in the old CI solid-spindle setup - but the CI cams had decent-sized oil holes to get lube to the cam bush/spindle interface.  I'm doubtful as to how much oil might find its way through the AVL's small-diameter hollow spindle to the center... especially when oil's cold/thick. 

Could THIS possibly be the reason for the increased wear claimed by Indian mechanics on AVL cams/spindles (remember we're in a context of poor maintenance standards where degraded oil may be run longer)?  Can't help but wonder if it wouldn't be good to have a full diameter somewhere on those AVL locknuts, such that they'd better "seal" in the timing cover and oil would only flow out of the groove ABOVE the centerline of the spindles... at least that might push a little more through the spindles, there might then be a LITTLE pressure / flow there at least.

Interesting sometimes trying to figure out what the engineers were trying to do, wish we could actually inquire of someone at AVL who worked on the redesign - in some ways such a great improvement, in others a bit baffling!


BUT... back to the main issue at hand re: the breather mod:  Since the timing chest runs with a pretty high oil level in it, if the crankcase was running (more?) negative pressure, it would suck that oil into the crankcase where the AVL lacks that crank seal.  The scavenging pump might not then be able to keep up with the increased amount of oil, instead of it's naturally flowing back into a similarly pressured tank as per stock design.  That's the "wet sumping" referred to, right? 

It's weird though... this missing crank seal seems to indicate that AVL actually purposely eliminated the vacuum in the crankcase, why else would they have deemed the oil seal unnecessary?  Either that or they were using any expected negative pressure to pull oil in and better lube the timing-side main bearing, and simply oversized the scavenging pump sufficiently that it would be able to keep up?  Or else???

ACE has said the lack of the oil seal is not "obviated"... I'm not completely clear what this means - would I want to entrust the whole functionality of the modded breather system to a felt seal that may or may not hold up long-term?  Or is it generally expected that it could work without it?

In short Has anyone actually changed an AVL back to the old breather setup successfully? I'd like a more efficient system but not so inclined to be a guinea-pig for the sake of a mere horsepower or so... :)  I'd kind of like to just get the bike back on the road now.  Not rushing anything, but would prefer to not embark on experimentation that could require subsequent major disassembly.

Ah, so after all the rambling:

1) my counterweight holes... likely damaged???
2) nuances of spindle lubing and efficacy of better sealing between them and the timing cover?
3) Has anyone actually converted an AVL to the old breather system successfully, without adding an oil seal?


Thanks All,
-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 27, 2019, 04:05:34 pm
I think the philosophy behind the omission of the oil seal behind the timing pinion on the AVL was something along the lines of: "We now have this gear scavenge pump which has a much higher capacity than the old plunger pump, so it will just clear any oil that has wet-sumped before it starts to get past the piston rings." My old Electra-X wet-sumped like anything, but I never had the clouds of smoke problem because it always DID pump the oil out first.

Then along came my fancy AVL hybrid engine based on a set of C.I. Bullet cases which HAVE the timing shaft seal, and which can smoke like cheap burgers on a barbeque on start-up. However as I have done some checks to prove it is not actual wet-sumping, and that th oil pumps are working fine, I'm putting that down to poor oil scraper rings.

Can't see why the old type breather won't work on an AVL any better or worse than on a C.I. Bullet, it only has to do the same job. It's also what the early 350 AVLs had.

(https://i.ebayimg.com/images/g/PR4AAOSwqspcuJ2J/s-l1600.jpg)

I'm sure a catch can will be fine.

Quote
A third machinist (things do tend to be a little compartmentalized here in India!) was entrusted with the job of installing a threaded insert where my front drain-plug had been cross-threaded.  He managed that reasonably well, but in the process clamped my engine case nice and tight in his knurled, iron-jawed vice and (obviously) marred the gasket surface... well, he charged $3 for his services and thank God for RTV, but really, this is becoming ridiculous.  There is a very good reason that bikes with unopened engines are strongly preferred purchases in India.

OUCH. :( I hope the insert didn't close up the oil drilling from the sump, I'm guessing you have checked this!

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on April 27, 2019, 04:32:18 pm
If you can get the lathe to work without enlarging the diameter of the bearing seat, then you should be able to use a 2205 bearing. Otherwise, the outer race could spin in the case, causing problems.

Regarding the timing seal, when the crankcase gets pumped down to low pressure, it will suck some oil in through that gap around the crank. I don't know how much will get sucked in. If the gear pumps can clear it, the Maybe there are no worries about it.

But, I would make that hole in the wall to the oil tank smaller, like the CI has, when you make the crankcase side breather arrangement.
The reason being that the hole sizes act as air metering orifices. If the hole to the oil tank is just as large as the crankcase side breather, about half of the air will get pumped into the oil tank, and half out the breather. This causes pumping losses, and also partially pressurizes the oil tank which impedes the evacuation of fumes from the top end.

You need to consider all of the effects on the breathing circuit when making major changes to the design like this. RE clearly didn't, which is why we try to restore it to the old CI breather design.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on April 27, 2019, 05:07:08 pm
The timing side crankshaft seal is 30mm O/D by 20mm I/D by 7mm thick, you can use a 5mm thick one to get the seal further in on the shaft. That's if you're ever letting any more Indian machinists anywhere near your castings.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on April 29, 2019, 10:42:46 am
Can't see why the old type breather won't work on an AVL any better or worse than on a C.I. Bullet, it only has to do the same job. It's also what the early 350 AVLs had.

(https://i.ebayimg.com/images/g/PR4AAOSwqspcuJ2J/s-l1600.jpg)

I'm sure a catch can will be fine.

OUCH. :( I hope the insert didn't close up the oil drilling from the sump, I'm guessing you have checked this!

A.

yes, thanks, I made sure about that oil passage, it's fine but that was the worst one to have cross-threaded on account of both that and the thinness of the casting there.  A press-in insert would have been better, but these had (coarse) external threads and it was pretty close.

So the early A350 had the old breather AND no crankseal?  If that's the case I'd have no reason for concern.

So anyone have any thoughts on welding the crankpin ends to the counterweights?  In my research seems not generally needed except on very high-powered engines... am just thinking of the abuses mine suffered in the hydraulic press... and its having already been apart twice.  I DO have a truly professional (expat) welder nearby.

It doesn't seem that any compensation for balance re: the weight of welds should be all that tough (saw BW's Youtube vid, lol...!). 

On those lines, my new, modified piston weighs 15g less than the stock one... so should I be re-balancing my crank anyway?

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on May 09, 2019, 08:11:59 am
(http://)

Ah, crap... wrongly thought my big-end axial (thrust) clearance was too small to feel, and didn't measure till now...when I finally felt it... Crank-assembly guy didn't use a feeler gauge, of course, and it's at .635mm and service limit is .65mm... here we go again.

1.  What do the builders out there consider ideal?  Range is 0.20-.55mm new.  Oh, and does anyone think it's a bad idea to assemble the engine with this crank, after having been harshly tweaked for straightness (not phase) in the wrong direction (.010" out - thinking of possible effects to my counterweight holes)?  I suppose BW might be the one to speak to this...

2.  On another note, can RTV or some other sealant be used in lieu of a gasket for the case-halves?  Did it on the cylinder earlier.  I've got plenty of axial clearance on the crank itself, so that's no issue.  We're not getting RE-supplied gaskets here now, the country-made gaskets are horrible, the one in my kit broke in three places...

Everything else is cleaned up nicely, and I hope about ready to assemble...

My NTN C3 main bearings have arrived and are installed in the cases...

CI tappet guides / tappets are in, got new spindles / sleeves in and a set of CI cams to play with.  We'll see how the pushrod lengths all work out and whether I have to notch the piston. 

Now off to the hydraulic press and lathe again...

-Eric

 
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on May 09, 2019, 02:54:39 pm
When I dismantled my old Electra-X (500 AVL) crankcases there was no gasket between the two halves, just some grey silicone, which I think was the factory method, gaskets being used on the cast iron models.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on May 11, 2019, 07:06:53 pm
When I dismantled my old Electra-X (500 AVL) crankcases there was no gasket between the two halves, just some grey silicone, which I think was the factory method, gaskets being used on the cast iron models.

A.

The Electra shop manual I finally found online mentions a gasket, but I went with RTV and expect it'll be fine, thanks.

Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on May 16, 2019, 09:03:18 am
Well, it's finally all back together and running well as of two evenings ago. 

After working with my helper on getting the engine/gearbox nicely mounted up in the chassis, cylinder/head/timing cover on and just about ready to finish up, I spent several hours taking it out and opening the crankcase again...

...when I found in my parts box that little ring-spacer that goes between the two drive-side bearings.... dang!  I'd been looking at that thing for weeks, conscious of the fact that it had to go back in there!

So now I've fully opened/re-assembled an AVL Bullet engine thrice, rather than twice...

My helper having departed for home, put the engine/gear back in the chassis and got back to the earlier point by myself this time... I think I strained my back/neck there a bit tho'...

Anyway, managed the old, smaller-base-circle CI cams with standard pushrods, just changed the adjusters (wound out about as far as they can go) to the old style to match the meatier old tappets down there.  Threads were the same.  Plenty-o-piston-to-valve-clearance there despite the higher lift of these cams. 

Spindles/eccentric sleeves are new aftermarket and a significantly snugger fit inside the cams than the original (even brand-new) AVL ones - I'd hoped this would quiet things down a bit, but no, just as clattery as ever when warm - just the nature of the beast, I suppose!

Bottom-end is very quiet vs. before, that timing-side bearing must have been on its way out for quite some time, almost from the beginning it had made noise under load when cold, and had been progressively taking longer and longer to quiet down as the engine warmed up.  That long, full-throttle, uphill run several weeks ago is what had finally finished it / make the source of the noise clear enough (kind of my objective in all the thrashing)! 

Fortunately nothing else damaged in the process.  Rod's got a little side-to-side as gauged from the small-end, manual tells how to measure it but no info re: the limits!  Anyway the big-end axial is towards the tighter end of the spec now vs. the max service limit as assembled by "an expert". 

Crank was trued (by me) to .0008" (.02mm), and the engine feels about as smooth as can be expected from a 500cc Bullet.  Never got an answer on balancing vs. my 15g's lighter piston vs. stock, so just left it. 

Bike's feeling healthy, I'm not in the mood to thrash it just now, I need it to run awhile without major dramas.  Friends coming over in August who want to ride up over the passes (13,500-17,000+ft !), someone or the other will likely be riding this one, so the day for thrashing will surely come.  it's probably been up there dozens of times, just not since I've had it.   

New (old-style) breather setup is done, but not ridden sufficiently as yet to properly assess.  Yes, continuous mist and a little oil spitting out of there, but I've got the OE can to hopefully reclaim most of that, will have to gauge its effectiveness over time.  Honestly I'm dubious about the duckbill's effectiveness as a check-valve... maybe mine's age-hardened?  I might have an easier time finding a proper PCV valve up here vs. a vacuum gauge to verify.  Might also consider a vertical run just out of the crankcase, to help keep any oil-spit down if need be.  As per ACE's advice plugged the 8mm hole between crankcase and oil tank, and drilled a 3mm right near it.  Also made a thin felt washer to go behind the timing pinion, I'd doubt much oil will be passing through there so long as that holds up, maybe even without it.   

Now one question: Should I just plug the original breather port atop the oil tank?  I can feel the pressure pulses there (due to the 3mm hole I guess), but don't see it really serving any purpose now.  Actually have capped it for the time being. 

I'd thought of trying out a 350cc header pipe, but found a calculator online suggesting the existing 1-1/8"ID pipe puts my peak torque around 2,800rpm, where a 1-1/2 would raise that somewhere above 4,000... I guess that's the OD on the 350, not the ID, but still, way down low at 2,800 seems about right for enthusiastic lower-speed street / hill use, so probably will save myself the trouble for now, I suppose it's the revs that are especially hard on everything else and command a lot of the more expensive upgrades anyway.

More later, I suppose there will always be something or the other:  1) I'd like to find a way to achieve a longer intake runner without having to have the filter taking over my (otherwise useful) side-box... and 2) Want to get some side-racks made for carrying fruit baskets (oh yes, I'm serious), as we make/market all-natural jam up here, and at the same time the coming months' tourism rush dictates another sort of "jam" clogging up roads and making arduous work of automobile travel...

For now a hearty thanks to all who've tolerated these ridiculously lengthy inquiries/musings and moreover have responded with repeatedly thoughtful, helpful advice and experiences.  There are a few of you who stand out in particular - you know who you are!

In closing: A friend is up visiting from Delhi who'd never ridden a Bullet... had been scared to, in fact, being they're reportedly so "heavy"!!!  But he took this one out and was surprised to find it so light to the touch and easy to handle - more so than his little 125 Honda, he claims... (I'm going to have to finally get my wife on this thing - the bike was kinda her idea and technically it's hers anyway!).

I had a neighbor's KTM Duke 390 at my disposal during the time the Bullet was apart... a bike I'd thought I was really going to enjoy riding.  The owner had learned to ride on a Bullet Machismo and told me, "wait till you ride the Duke".  Well.  I rode it.  I thrashed it.  Had to, to enjoy it at all - life begins above 5,000rpm's.  I dunno, maybe it's 'cause I'm 50 years old, maybe it's just because a smallish-cc race-tuned bike is pretty impracticable on the street, maybe it's because I didn't have room for my knees - but I just didn't like it. 

So long live the Bullet Machismo...
These are certainly interesting, unique machines, and worth a bit of trouble I suppose.

-Eric





Warm Regards,
Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on May 16, 2019, 01:54:47 pm
Glad you're pretty much there with this bike at last, you seem to have achieved expert status!

Yeah, ditch the duckbill and get a proper non-return valve, I think would keep the oil tank top vent open too (with another non-return valve) as you still have a small hole into the crankcase, and you have all the stuff coming down from the top end too, all this piles into the oil tank from the timing chest.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on May 16, 2019, 02:11:51 pm
Good show!

Watch those threaded pushrods adjusters. They bend rather easily when they are adjusted far out. You might put an extra locknut on the bare threaded area, and tighten it up to the pushrod to add support to the long exposed threaded shanks, effectively simulating a longer pushrod. Don't worry about the little bit of added weight.

Don't try to make these engine's valvetrains run quiet. They are supposed to make noise because they are running tappet clearance at the rockers, and they can never be quiet. Any attempts to quiet them will result in damage, even if at takes some time to occur.

Rod side play at the big end bearing should be more than .005" , but less than .020".

IMO, you should leave the oil tank breather plugged now. The breathing circuit relies on low crankcase depression to pull the fumes from the top end down thru the oil tank, so they can be expelled on the downstroke. My feeling is that oil tank venting or any other vent location defeats the designed intent of the breather circuit. That's my 2 cents on that subject.

The duckbill is very low cost, so get a new one If you suspect it might be hardened up. You can use a PCV, but I think the duckbill works better. The very best option(expensive) is the KrankVent. Racers use it.
The oil mist coming out will greatly reduce as the rings get sealed better, by about 500 miles or so.

No need to worry about crank balancing for small changes in mass. A single is inherently unbalanced, and you are only slightly changing the reciprocating mass for the better, by a little bit. It reduces the vertical(primary) vibration component very slightly, and has no effect on the horizontal(secondary) vibration component.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on May 20, 2019, 06:14:05 pm
Axial on the big end is about .009" now, down from around .025"!!!

Previous owner of this bike (and about thirty others like it) said he sometimes "lengthened" pushrods with a washer/spacer between the rods and upper ball-ends.  Being press-fit and under compression vs. tension, I guess they're not going anywhere.  Maybe this is something like what Adrian described earlier, and I could turn a couple on the lathe in aluminum easily enough.

Still haven't ridden it crazy-like but it's feeling really strong.  Now if only I could find new washers for the bad, leaking ones at the oil-line banjo bolts...

Friend currently borrowing it for a few days, was hesitant to do so but he's Indian and doesn't seem to take it beyond 1,500revs, so guess we're alright!

-Eric 
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on May 20, 2019, 07:05:41 pm
Maybe you can find some soft brass washers for the banjos, if you can't find copper.

I have successfully used brass washers in the banjos.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on May 21, 2019, 12:15:29 pm
Quote
but he's Indian and doesn't seem to take it beyond 1,500revs

Just so long as he doesn't try and lug the engine in higher gears, that's not big-end friendly.

I'm toying with the idea of making my own push-rods from solid 10mm ally rod, taken down to 9.7mm at the bottom and threaded for 1/8" BSPP hex blanking caps for adjuster use, with stud and bearing grade Loctite keeping it all in place, then drill and tap these 1/4" BSC for the iron barrel tappet adjusters. The tops could be drilled and tapped 6mm if the AVL tappet adjuster ball ends aren't too big to fit the AVL rockers.  1/8" BSPP is a fairly fine thread.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on August 01, 2019, 07:53:25 pm
I'm toying with the idea of making my own push-rods from solid 10mm ally rod, taken down to 9.7mm at the bottom and threaded for 1/8" BSPP hex blanking caps for adjuster use, with stud and bearing grade Loctite keeping it all in place, then drill and tap these 1/4" BSC for the iron barrel tappet adjusters. The tops could be drilled and tapped 6mm if the AVL tappet adjuster ball ends aren't too big to fit the AVL rockers.  1/8" BSPP is a fairly fine thread.

A.

I haven't checked the forum for a couple months I guess.  Interesting, I just modded my pushrods today, maybe something not unlike what you're outlining here.  They had seemed a weak link to me especially being so far wound out, despite my having put spacers over the threads 'twixt the locknut and pushrod to help strengthen that rather spindly thread on the (late CI, metric) adjuster  cup, one of which was already bent slightly (it was a second-hand piece I'd put in "temporarily").  As noted earlier, I still had a lot of valvetrain noise of uncertain origin, and it's been seriously irritating my tinnitus.  Today that was solved, maybe partly as a function of having both my adjusters actually straight.

Other possible noise source: A few weeks ago had the timing cover off and observed that cam gear backlash was not consistent from one point of rotation to another (yes, had the pushrods out, so fully unloaded).  When I'd set them correctly at their point of tightest interference, then at other points the gears meshed loose enough to likely be causing some of my rattle.  Wasn't sure if this was due to wear (they were a used set of CI cams I'd just been experimenting with), or (more likely) poor machining on RE's part.  The new OE ones I put in today are still not perfect in this regard (so it probably is the machining more than wear), but they seem better than those I had in there.  I've still got more backlash on one side of the gear than the other, but not too bad.   

Also noted that even when pushrods are set to zero clearance cold, they become really loose when hot.  I mean, REALLY loose.  Which means the cylinder/head are expanding a lot more than the pushrods, despite both being aluminum.  This seems a curious thing that I guess can only be indicative of temperature differences amongst components.  Short of fitting a CI cylinder block or finding a pushrod material with a much higher coefficient of thermal expansion (not likely), the quest for a quiet AVL might end here, I thought.   
 
Anyway, what I ultimately did was found a set of old CI pushrods with the 1/4-28 adjuster threads, these are substantially beefier than the M6's on late CI's / AVL's.  So I figured that would largely eliminate the possibility of bending.  Only trouble being that CI pushrods are hollow and without fabricating a bushing (not a lathe owner at present), the ID is too large to provide the needed press-fit for the little spherical steel nib from the AVL pushrod's top end.  And I think there were problems on the early AVL's with pushrods bending - I'm going to guess in the hollow design being carried over from the CI's.  Other problem is that the ID of the CI adjuster assembly, where it press-fits onto the machined OD of the pushrod, is larger.  So no press-fit available there, either. 

So here's what I did: Removed the complete adjuster from the old-model CI pushrod.  Removed the steel nib from the AVL pushrod top-end.  Inverted the AVL pushrod.  Drilled out the threaded (originally bottom) end of the pushrod sufficient to provide the press-fit for the nib, and pressed it in.  On the other (originally top) end, I drilled out the original nib-hole to 1/4" to allow clearance for the new, larger adjuster threads, then pressed the complete adjuster assembly on that end.  Depending on the particular pushrod's OD, it may or may not press-fit directly - my original pushrods were a perfect OD for it.  If the pushrods' OD is too large (like my RE replacements), the OD can be turned down slightly (mount rod in hand drill and use flat-file/emery cloth) to provide the proper press-fit. 
 
So basically I've got upside-down solid aluminum AVL push-rods with AVL top nibs and the beefy old-model 1/4-28 adjuster cups.  In my case I also shortened my pushrods by a few mm's to allow for enough adjustment, but that's mainly because my cylinder was shortened by 2.5mm.  This would not be necessary for everyone. 

As outlined earlier, I had installed the larger-diameter CI tappets at the time of my last rebuild, and now with the stronger adjusters, I'm feeling much confident about valvetrain reliability now.  Besides tappet feet sometimes breaking off, the AVL's were known (here in India at least) to "throw" the pushrods, meaning they'd sometimes fall out of the fairly shallow little sockets in the OE AVL tappets. 

Only possible downside in all this is that everything's now a LOT heavier than stock.  I've got CI tappets which are a LOT heavier than the AVL's.  I've got solid AVL pushrods which are a LOT heavier than the hollow CI's.  And I've got the old-version CI adjuster assemblies which are a LOT heavier than the AVL's tiny bits.  If I were building something with the idea of high-revs, I'd turn down / eliminate whatever I could on the adjusters to lose some weight there, or else drill/tap the original AVL hardware, which is a lot smaller/lighter, to accept the 1/4-28 cups.  And I'd probably go with the tubular pushrods, too, all in the interest of avoiding valve-float.  For my intended rpm range, I don't expect problems.   

Bike's been running really great, really strong, about as much power as I feel I would ever need with local roads in view, extremely responsive and certainly pulls a fair bit harder than a stock AVL, that across the entire rev range.  I've still not really revved it near redline (whatever that is), mainly because I actually don't need to in order to move along briskly, also because I've got this extra power working on a stock crank and don't really want to push the limits till I've at least got some good use out of the bike.  I figure a year from now I might be in the mood to pull it all apart again... and if so will do the crankpin and bearing up better. 

For now, might change the oil and then am hoping to just ride it for some months with minimal fiddling.  If my warmup and short ride home this evening were any indication, it's quieter than it has ever been, quieter even than some of the hydraulic-lifter UCE's I hear running around.  Probably going to take it out to Lahaul/Spiti valleys with some riding buddies in a couple weeks.  Only a measly little 13,500ft pass between here and there (I'm sure the bike has been above 18,000 more than once before I owned it), lol. 

-Eric
 
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on August 01, 2019, 08:34:58 pm
Avoid all temptation to make it quiet. It was designed and always intended to be noisy. If it's quiet, something is certain to go wrong.

Regarding the pushrods hot clearance, it is doing exactly what it is supposed to do. That is called valve lash, and all flat tappet valvetrains require it for proper running. Zero clearance cold yields about .012" clearance hot, and that is how it is designed. Do not try to circumvent that.

Regarding cam gears being somewhat eccentric, welcome to royal enfield. You might find a set that are better, or put two cams from different sets together to make a good set, but it may take some looking around.

My suggestion is to get accustomed to the sounds of the engine and enjoy the bike.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on August 02, 2019, 05:29:17 pm
Yeah, thanks ACE, I read your comments earlier re: noise, and understand about valve-lash, etc.  But observe a fleet of thirty identical bikes all maintained by the same mechanic for ten years, and you do find some that are relatively quieter than others.  Note that I used the word "quieter" vs "quiet" which certainly cannot be expected (and the UCE's here have a lot of issues with loose/defective hydraulic tappet, some being replaced under warranty on near-new bikes.  These days dozens and sometimes hundreds of UCE's, along with a handful of AVL's / CI's go past daily fifteen feet from our door, so I have opportunity to hear the full range.  My AVL had what I could safely call an abnormally nasty clatter only in one specific rpm range, outside which it was just sort of the normal ticking noises I could easily bear with and even appreciate for its mechanical "honesty". 

Regarding valve clearance, I know it is necessary but it is also clear that Iron blocks expand less than aluminum, and being that these also call for zero lash cold, they obviously run with less lash hot than do the AVL's (hence are quieter and still safe!).

My theory re: my particular noise problem was that within that particular rpm range, when on the downramp of the cam lobe, the valvespring tension was actually accelerating the cam against whatever backlash existed.  Exacerbated by the problem of not being able to set backlash properly on account of the gears' unintended eccentricity.  At higher rpm's, inertia took over and the slight acceleration/deceleration of the cam disappeared, the backlash becoming immaterial and things becoming quieter. 

Having said all this, I wouldn't bother at all except for my persistent and easily irritated tinnitus (had it since childhood)... two months away from the bike last winter and it had nearly disappeared, back on it for less then ten miles and it was back with a vengeance (earplugs only help a bit with particular frequencies).  End of the day, I don't have the tappets or cams set overly tight, and new RE cams only cost me under $30, so it seemed worth the cost in time/effort.

)Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on August 02, 2019, 05:55:57 pm
part of Adrian's idea for pushrods might be right on:  need to measure but the ball-end of the AVL adjuster seems the same as the upper-end nib.  So if the rod itself is threaded (my replacement was), just keep that threaded ball-end (only) threaded into the bare pushrod, then invert and press-fit the complete 1/4" CI adjuster into the bottom  (originally the upper end), which has been drilled out to 1/4" to allow the threads to pass up into it if/when needed.  Advantages being that now only one end of the rod need be drilled (and that only imprecisely) - And moreover I gain more adjustment leeway by now having threads on both ends.  Depending on setup / components, helpful if I ever needed to go a bit longer.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on August 02, 2019, 06:11:47 pm
I have tried extracting the plain top of the AVL push-rod. It works, but it wrecks the plain top in the process, also be very careful or you will damage the alloy of the push rod. The good news is that the old plain top's stem where it inserts into the ally is 5mm diameter, so the resultant hole which is left is actually the correct tapping size for the AVL adjusters' 6mm thread. Careful drilling with a 5mm drill will allow you to deepen it if necessary before cutting the M6 thread.

ISTRC from ASBO12 that the extra length needed on both rods is about 9.5mm or 3/8 inch. The business end of the screw-in adjuster is slightly taller than the external portion of the plain push rod top, only by about 0.5mm or so.

Will try and get a picture of it.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on August 02, 2019, 06:32:36 pm
I have tried extracting the plain top of the AVL The good news is that the old plain top's stem where it inserts into the ally is 5mm diameter, so the resultant hole which is left is actually the correct tapping size for the AVL adjusters' 6mm thread. Careful drilling with a 5mm drill will allow you to deepen it if necessary before cutting the M6 thread.

ISTRC from ASBO12 that the extra length needed on both rods is about 9.5mm or 3/8 inch. The business end of the screw-in adjuster is slightly taller than the external portion of the plain push rod top, only by about 0.5mm or so.

Will try and get a picture of it.

A.

Actually not all AVL top-end ball-nib stems have the same press-fit diameter.  My originals were 5mm as you found, but the OE RE replacements I bought used a 6mm press-fit!!!  Rod OD's also differed considerably between both these, even from one end to the other... so it may all have to be taken on a case-by-case basis.  Or else fabricate from scratch with known superior material, which might also prove simpler at the end of it.

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on August 02, 2019, 09:20:46 pm
At least that way you know what you're getting.  ;)

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on August 25, 2019, 07:22:44 pm
Finally a visit from a few friends eager to ride gave me the excuse to get up and over 13,500ft Rohtang Pass on the Machismo.  Been waiting a long while for this despite its being so nearby.

So five of us bearded gringos, with the AVL and also my little Honda dual-sport along, plus three rented G5's (a.k.a. Bullet 500 Standard, in both carb and FI form).

Destination was originally supposed to be Kaza, Spiti Valley, which would have taken us over Kunzum-La pass as well, and to Chandra-Tal lake, etc, etc, where there is some very challenging riding.  As it was, due to some recent flooding and road damage, friends were all delayed in the capital and we ended up with only two days to spend... So destination changed to Jispa, a village of sorts in Lahaul valley.  Anyway.

Great time out there, each bike with its particular merits, I rode them all at various points.  But overall have to say our Machismo was by far the best:  Just so eager and effortless in its present form; suspension seems about right (some very rough patches there handled fine, as were the well-paved twisties).  The exhaust note is truly sweet (if a bit loud) vs. the newer (UCE) machines, and it is a good looker, even when dirty (which is pretty much always) - it was clearly the most photographed of the bunch.  A very pretty part of the Himalayas to be sure (and what part isn't pretty?).

The G5's certainly deserve honorable mention here... everyone in the group liked them, incl. a guy who's been riding V-Star and Sportster 1200 stateside.  They are actually a very impressive all-rounder... can be thrashed off-road if desired, handle quite well on good pavement too, have an adequate amount of pull for secondary roads, are a lot quieter running than the AVL's, and have surprisingly comfy seats and suspensions.  They do vibe a LOT in a harsher way than the AVL's IMO, I've observed this with other examples of both earlier.  And the styling doesn't personally move me much.  But still...

Planning to pick up a bit of a beater 2013 model in the morning.  Mechanically really solid (rebuilt) so not planning to get into it much - the AVL has been quite an education / time-consumer and not looking to repeat.  But expect I'll be perusing the UCE threads a bit more in the coming days...

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on August 25, 2019, 10:30:36 pm
I think they really made a mistake in dumping the AVL 500 so quickly, especially if so many of the UCE bikes were still carburetor-fitted.

A.
Title: Re: First AVL ownership/build... tech questions...
Post by: ringoism on September 14, 2019, 04:57:19 pm
How are we supposed to check ignition timing on these AVL's?

I don't think mine would be as far out as some seem to be, but still...

-Eric
Title: Re: First AVL ownership/build... tech questions...
Post by: tooseevee on September 14, 2019, 05:47:37 pm
How are we supposed to check ignition timing on these AVL's?

I don't think mine would be as far out as some seem to be, but still...

-Eric

       That's a damn good question :)

        I can visualize the two ways I would try to do it, but both ways won't work:

        (1)  The first way would throw oil all over the bike, you, the driveway, the garage, the house, the neighbor's house plus you'd never get it right  :( :(

         (B)  The other way the plug wouldn't get its  "fire" signal (on the vintage bikes, that's where the points open, ammeter deflects ((I think)) )  >:( >:((http://)
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on September 14, 2019, 07:57:31 pm
How are we supposed to check ignition timing on these AVL's?

I don't think mine would be as far out as some seem to be, but still...

-Eric

Rebuild the AVL engine using a set of modified classic Iron Barrel 500 Bullet cases and fit the ignition of your choice. I am currently working on one of these!

A.

 
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on September 16, 2019, 01:29:01 pm
Use the 0.8mm BTDC timing stick on the piston, like an iron barrel.
A normal 12vdc test light on the negative terminal of the coil should still show the circuit interruption when the ignition fires the coil.
Rock the piston back so it is a bit more down the hole BTDC, and then slowly rotate engine by hand in running direction very slowly until the test light flickers or goes out. Look at the timing stick, and see if it is at/near the 0.8mmBTDC mark on the stick.

You only have a little bit of leeway for moving the sensor block anyway, but you should be able to see if it fires in the correct range.

I have not actually done this on an AVL, but in theory it should work.
Title: Re: First AVL ownership/build... tech questions...
Post by: tooseevee on September 16, 2019, 06:55:31 pm
Use the 0.8mm BTDC timing stick on the piston, like an iron barrel.
A normal 12vdc test light on the negative terminal of the coil should still show the circuit interruption when the ignition fires the coil.
Rock the piston back so it is a bit more down the hole BTDC, and then slowly rotate engine by hand in running direction very slowly until the test light flickers or goes out. Look at the timing stick, and see if it is at/near the 0.8mmBTDC mark on the stick.

You only have a little bit of leeway for moving the sensor block anyway, but you should be able to see if it fires in the correct range.

I have not actually done this on an AVL, but in theory it should work.

        I didn't think (and I don't know if) the Hall Effect in the AVL would light a test light as points ignitions do (when the points open).
Title: Re: First AVL ownership/build... tech questions...
Post by: ace.cafe on September 16, 2019, 10:30:05 pm
Well, I figure that if it has a coil, then the field has to be collapsed to fire the plug. The field collapses when the circuit is broken on the negative side of the coil, just like points. In an electronic ignition, typically they use a transistor to do the switching instead of points. Either way, it has to open that coil circuit, so you should be able to see it on a test light.
Title: Re: First AVL ownership/build... tech questions...
Post by: Adrian II on September 17, 2019, 12:00:31 am
ISTRC Bullet Whisperer drilling a hole in the top of the outer chaincase and fitting a plug, so that the ignition could be checked with a strobe.

A.