[Bullet Whisperer]

I thought this might be of interest to some. I have tuned a couple of these machines in the past, with quite good results, but this is the first time I have been asked to do what I can with a cylinder head for one, so ...

https://youtu.be/FyTY1hQoec4

B.W.

[gizzo]

Thanks for posting that. I've done similar work to mine recently. Not as much as yours, or as well, but I feel it's made an improvement. Mine was just port matching the inlet (like yours, there was quite a step all the way around to grind out) line the insulator up with the port properly and clean up the exhaust. I didn't touch the combustion chamber but maybe that's worth revisiting. It doesn't do 100mph (I don't think it's any higher top speed) but it gets there quicker.

[Arschloch]

Thanks for posting that. I've done similar work to mine recently. Not as much as yours, or as well, but I feel it's made an improvement. Mine was just port matching the inlet (like yours, there was quite a step all the way around to grind out) line the insulator up with the port properly and clean up the exhaust. I didn't touch the combustion chamber but maybe that's worth revisiting. It doesn't do 100mph (I don't think it's any higher top speed) but it gets there quicker.

If you run it with the stock cams the stock head won't give as much improvement no matter how nicely you port it. Lift and valve timing remain unchanged.

[Bullet Whisperer]

If you run it with the stock cams the stock head won't give as much improvement no matter how nicely you port it. Lift and valve timing remain unchanged.

The one I am working on will be getting the hotter cams [when the next batch is ready from Hitchcocks], with the inlet cam timing retarded, as per the yellow machine in this clip ...

 https://youtu.be/IRr8P0TnbBA

 I also tuned a green one prior to that, basically the same, but with the Hitchcocks cams timed on the marks ...

 https://youtu.be/iO00SldM1J4

 Neither the green or the yellow machine had any porting work done, so, in theory at least, this latest machine ought to have an edge over both of them.
 B.W.
 

[Bullet Whisperer]

Oh dear, a sad internet troll calling itself Gibbons has seen right through it all and left a comment on you tube. Both Hitchcocks and I am done for now ...
'It's a make-believe carb conversion, with dummy plugs ans such, nor real and not a full conversion. Pathetic.
And, why would yo take a client's bike on a test drive in rain ...?! '
 B.W.

[wr6133]

I don't get the point of the conversion compared to a PCV but his comments are retarded.... "Dummy plugs"

Off topic, if you want to defeat the wind noise and your cam doesn't support an external mic, you can use a cheap bluetooth setup in your lid to record the sound to a phone and then splice the video and audio afterward.

[Arschloch]

Just one internet troll takes you and H's down? ....concider yourself lucky thousands real life trolls there Sweden as well as internet trolls.

All busy finding theories and scientific proof that the wheel is a fake invention. 

[Bullet Whisperer]

I don't get the point of the conversion compared to a PCV but his comments are retarded.... "Dummy plugs"

Off topic, if you want to defeat the wind noise and your cam doesn't support an external mic, you can use a cheap bluetooth setup in your lid to record the sound to a phone and then splice the video and audio afterward.

Thanks - I have since found covering the mic hole in the camera with sticky tape does a lot to help against any wind noise.
 B.W.

[Bullet Whisperer]

Just one internet troll takes you and H's down? ....concider yourself lucky thousands real life trolls there Sweden as well as internet trolls.

All busy finding theories and scientific proof that the wheel is a fake invention. 

I am sure it will take more than he / she / it has to put me and / or Hitchcocks off, but whoever it is seems to have a deep hatred of anyone improving the performance of a 535 CGT in this way, going by this and other comments they made on another video about tuning  these machines. Wonder why ...

[Richard230]

I never understood the YouTube viewers who hit the thumbs down button on what seems like perfectly good videos that the preparer obviously put a lot of work into producing. One classic example is how many dislikes that Itchy Boots would pick up and without any corresponding comments explaining why they didn't like the video. My feeling is that if you don't like a video, just don't bother watching it (or its ads  ) and move on to something else. Why make the person who prepared it feel bad about getting dislikes without knowing why and perhaps how they could improve their next publication? But it does seem to be a thing. I don't think that I have ever seen a YouTube video that didn't have some dislikes if it had been out for more than a few days. 

[Arschloch]

@Richard320: I assume you are old enough to know there are sob's on this planet that prefere to win by handicapping the opponent.

[Richard230]

@Richard320: I assume you are old enough to know there are sob's on this planet that prefere to win by handicapping the opponent.

True, there is no question about that, unfortunately.       There are a great many people who would prefer to drag down others to their level instead of trying to improve themselves. And in many countries that starts at an early age and is encouraged by both the media and politicians, as I am sure you are aware. 

[Adrian II]

OK, some bad people have internet access. If he makes himself objectionable behind a keyboard he may very well be just as "pleasant" in real life.

The reaction to the work of B.W. (and other serious old bike wizards) is enthusiastic/supportive enough where it really counts, from what I've read across various forums and FB groups (as well as most of the youtube comments).

Looking forward to seeing the test ride with those cams in. 

A.

[Guaire]

Does Hitchcock’s have these cams on their website?

[Bullet Whisperer]

Does Hitchcock’s have these cams on their website?

As I understand it, they are hoping to have more performance cams in soon, i have my name down for one set 
 B.W.

[ace.cafe]

Do you know what is their spec for the lifts at the lobes?

Interested to find out if they will work with our billet head.

[Bullet Whisperer]

Do you know what is their spec for the lifts at the lobes?

Interested to find out if they will work with our billet head.

Hi Ace - not at present, but I have a few photos, some a bit blurry, of the original and replacement cams from CGT Asbo 24, from a few years back, which might be of interest.
 B.W.

[ace.cafe]

Thanks BW.

Hard to tell about the lift, but the flanks look very aggressive.

[Adrian II]

Looks like performance cams have a smaller base circle.

A.

[Arschloch]

I remember reading long time back something about 0.4" lift. On the picture however, knowing the hole is 5/8" it looks more like 0.35" lift.

[Jako]

Hitchcock's  specs

[Arschloch]

Intake cam, 11.3mm = 0.44" that would lead in my fireball engine to a lift on the intake valve of 0.63".

[ace.cafe]

Hitchcock's  specs

Thanks!

Those cams have quite long duration, apparently aimed at high rpms, or maybe aimed at the 612 .

[ace.cafe]

Intake cam, 11.3mm = 0.44" that would lead in my fireball engine to a lift on the intake valve of 0.63".

It appears to me that the specs are given at the valve, because of the way they wrote the description as approximate and @1mm clearance.

In that case, assuming 1.25:1 stock rocker ratio we would be looking at something closer to .352" lift on the intake lobe to get .440" lift at the valve. Of course, these cams were made to run on the stock platform, so the lobe lift was spec'd to give good lift in that application. It is noted that things vary in the stock application, notably rocker ratio which could be less than 1.25:1.

On the Fireball rocker ratio, that would give about .510"(13mm) lift on the intake valve, which should be within limits.

It would remain to be seen if that much duration would be good on the street with a 535 and a 6500rpm limit, with a high breathing head. If there was no rev limiter involved, it could become interesting at higher rpms above 6500.
Might be worth a try, but careful measurements on piston/valve clearance would be needed, and check if reaching valve spring bind at full lift.

[Bullet Whisperer]

Ace, this machine had no work done to the head, other than fitting the Hitchcocks valves and springs. I shortened the barrel by a little over 1 mm in this case, fitted an Amal carb kit and those Hitchcocks cams, but I retarded the inlet by 1 tooth ...
 Check out the overtake in 2nd gear, at around 6 minutes, as well as some of the faster stuff towards the end of the video. It revved to around 6,500 RPM.
 
https://youtu.be/IRr8P0TnbBA

 B.W.

[Arschloch]

It appears to me that the specs are given at the valve, because of the way they wrote the description as approximate and @1mm clearance.

In that case, assuming 1.25:1 stock rocker ratio we would be looking at something closer to .352" lift on the intake lobe to get .440" lift at the valve. Of course, these cams were made to run on the stock platform, so the lobe lift was spec'd to give good lift in that application. It is noted that things vary in the stock application, notably rocker ratio which could be less than 1.25:1.

On the Fireball rocker ratio, that would give about .510"(13mm) lift on the intake valve, which should be within limits.

It would remain to be seen if that much duration would be good on the street with a 535 and a 6500rpm limit, with a high breathing head. If there was no rev limiter involved, it could become interesting at higher rpms above 6500.
Might be worth a try, but careful measurements on piston/valve clearance would be needed, and check if reaching valve spring bind at full lift.

That seems to be the case, 0.44" at the valve not the lobe.

I've got 0.5" lift at the intake valve now which means it should result in about the same lift. Not to inclined to try it because the bronze bushings would size in my configuration on a hot day. I've ruined 2 sets of cams until I've finally gave up and went for rollers on the axles.

[ace.cafe]

Hi Paul,
 She goes quite well, and is a real looker too. Ticks over nicely, and seems well behaved around town, as well.

I had a hard time seeing the gauge needles for much of the show, but you seem to have answered my question at the end. Have you raised the rev limiter to 6500 rpm on this bike?

I have no doubts at all about the improved higher rpm performance with these cams, particularly with the retarded inlet.

Have you tried doing a compression test on it?
My past experiences with a full-tooth retarded inlet gave room for a higher compression piston. I was thinking that it may be a candidate for your AVL stepped piston crown treatment.
It would seem a natural fit, since the piston and combustion chamber are almost identical.
Just a thought.

Good show overall, and I am certain the owner will be very happy. I would be very happy with it myself.

[wr6133]

Possible dumb question.......... You are getting round the RPM limiter on the ECU, I thought these were normally based on cutting the spark so wondering how you managed to get round that without a Power Commander?

[Bullet Whisperer]

I can honestly say rev limiters and having to get round them were never considered on either the green or yellow machines I have tuned to date, although they both had non standard exhausts fitted before they came to me for work, so maybe other stuff was changed too, when the exhausts were changed. That said, neither machine could reach 5000 RPM before I did the tuning work on them and I have to wonder, with the standard cams and valve springs looking suspiciously like those from the AVL / Electra X models, whether these, once again, are what is responsible for limiting the revs?
 B.W.

[Arschloch]

So unless these bikes have been equipped with a power commander and the rev-extend function activated beforehand it would indicate that the ECU cuts of the fuel supply and leaves the ignition untouched. By replacing the throttle body with a carb there may not be any rev limiter.

[Bullet Whisperer]

So unless these bikes have been equipped with a power commander and the rev-extend function activated beforehand it would indicate that the ECU cuts of the fuel supply and leaves the ignition untouched. By replacing the throttle body with a carb there may not be any rev limiter.

Possibly, although both machines I tuned also had their cams, valves and valve springs changed. Incidentally, I have this latest machine running now, but it is waiting for cams, with all the other changes [except for exhaust system] now made. I have not ridden it yet, but running it on the bike lift, it seemed to rev freely past 6000 RPM on a couple of initial twists of the throttle, but then do a funny sort of misfiring thing. If I let it settle down for a moment, it would reve right up again a couple of times, then lose interest again. It has very good fuel flow to the [in this instance for some reason] Mikuni carburettor, so, all a bit odd. I might get a run on it in the next few days, to see what it is like before the cams and exhaust are changed.
 B.W.

[Adrian II]

Hitchcocks' early carb conversions for the EFI bikes replaced the alternator rotor and ECU with Electra-X items, so there was just the straightforward TCI function and no other bits of electronic trickery to worry about. Then they found a way of keeping the EFI ECU and rotor and fooling it into governing the spark advance only. Without seeing the instructions I wouldn't know which bits have to remain connected and which bits are turned off/bypassed!

A.

[Arschloch]

Even if I should put a carb on mine in the future I would still like the PCV in there even if only for adjustment of the timing. Very happy with the possibility to adjust the ignition at any given rev range and retard it to ignite after TDC below 1000rpm. No risk of broken legs while kicking.

The chainsaw like decompression working fine as well.

[Adrian II]

The decomp valve option is a neat feature of the ACE head, though on the production CGT heads there's only the one spark plug hole. I see that Indian home market 500 EFI heads were twin plugged from stock, don't know why they didn't offer that on the export EFIs, CGT included. That would have allowed owners the choice between twin sparks or decomp.

I can't remember all the details of your build, does it have solid lifters? I assume an alternative decompressor is needed once you start using custom cams on the EFI engines.

A.

[Arschloch]

There is enough space in the stock head to drill a second plug tap into it. The chainsaw like works well, just push and keep kicking. Took a bit of a search to find a vintage looking one with the brass button.

Lifters are still hydraulic, no issues at 6500rpm.

[Adrian II]

There is enough space in the stock head to drill a second plug tap into it.

I have done this with a couple of Electra-X cylinder heads, normal M14 x 1.25 thread, though the UCE/EFI heads have quite a lot less space between the rocker housings. I suspect it would be limited to a M10 thread by the lack of spanner room.

A.

[Arschloch]

True, there is no question about that, unfortunately.       There are a great many people who would prefer to drag down others to their level instead of trying to improve themselves. And in many countries that starts at an early age and is encouraged by both the media and politicians, as I am sure you are aware. 

OTOH...the companies and corpies that sell other peoples stuff earning rightfully hatered and shit storm. The people who built and created the stuff these accounts sell are not there anyway. Why are the accountants, administrators and self appointed leaders taking a pay check anyway if they are so selfless. Everyone else is "best" and a potential Hitler. No, it's only garbage left in those places.

[Bullet Whisperer]

In answer to the above, my troll revealed itself to some degree by 'coming out' on the Hitchcocks forum, with more unpleasant remarks there and even 'quoting' me with something I never said, in addition to quite a few rather spiteful comments on you tube, where videos I made about UCE and CGT stuff seemed to be the focal point. I think there was an element of 'Green eyed monster', as well as more than a slight dislike of Hitchcocks carburettor conversions for some reason. It will not put me off in the slightest, but it needn't ever ask me for any help, not that it is ever likely to, knowing so much more than me and everybody else in the first place 
 B.W.

[Arschloch]

Maybe it is just one of those soviet bots residing in swedish Oceania, always ahead of everyone.

[Arschloch]

It will not put me off in the slightest, but it needn't ever ask me for any help, not that it is ever likely to, knowing so much more than me and everybody else in the first place 
 B.W.

Regarding help, it's better to purchase the help that's needed anyway. Than you can return it atleast if it's not accordingly to spec.

[ace.cafe]

BW,
I have had some people treat me that way too. You have the right way of handling it.

[Arschloch]

Regarding help, it's better to purchase the help that's needed anyway. Than you can return it atleast if it's not accordingly to spec.

That said I have a spare GT535 crank with a totally worn out big end bearing. The Idea is to shorten the stroke on it and put a slightly longer Jawa Speedway conrod in there with a bearing of the best  quality money can buy. If you are interested you can have the job. I'm just putting the stuff together. The big end on those rods has got the same dimensions as a the stock UCE. I suspect that these Jawa conrods come directly from Carrillo.

[Softlysoftlycatcheemonkey]

   About a year ago I became interested in motorcycles again after having none since 1994 and waded into it to arrive at a new 2015 ( fresh frozen )yellow Royal Enfield Continental GT in March. During that initial itch I found Paul Henshaw's Youtube content and then this forum, and these probably sold me on this bike. I'll probably be improving the machine as it's a pleasure to just stand next to, but the "shortcomings" cause me to itch even more. I've wanted to ask questions and interject to the work I've seen done by you gentlemen during this year, but withheld out of inexperience and could only blurt out in defense of mourning. Your work is, though, is appreciated by the living.

[Arschloch]

   About a year ago I became interested in motorcycles again after having none since 1994 and waded into it to arrive at a new 2015 ( fresh frozen )yellow Royal Enfield Continental GT in March. During that initial itch I found Paul Henshaw's Youtube content and then this forum, and these probably sold me on this bike. I'll probably be improving the machine as it's a pleasure to just stand next to, but the "shortcomings" cause me to itch even more. I've wanted to ask questions and interject to the work I've seen done by you gentlemen during this year, but withheld out of inexperience and could only blurt out in defense of mourning. Your work is, though, is appreciated by the living.

The shortcomings of this machines are what makes them interesting. The other aspect is, the tech you will ever need to heal them is within of anyone's reach. Furthermore anything you do to it, you can do under your own autocratic command, maybe the most interesting aspect, the result is yours if you are happy with it than that's all that matters. Nobody has all the answers though, sometimes you have to find it yourself nevertheless anyone asking questions has found good help on the pages of this forum.

Good luck!

[Bullet Whisperer]

BW,
I have had some people treat me that way too. You have the right way of handling it.

Thanks Ace!
 B.W.

[Bullet Whisperer]

That said I have a spare GT535 crank with a totally worn out big end bearing. The Idea is to shorten the stroke on it and put a slightly longer Jawa Speedway conrod in there with a bearing of the best  quality money can buy. If you are interested you can have the job. I'm just putting the stuff together. The big end on those rods has got the same dimensions as a the stock UCE. I suspect that these Jawa conrods come directly from Carrillo.

Thanks, Otto.
 To be honest, altering the stroke of a crank would be beyond what I can do here, but I am always happy to share what I have done and how I did it [most of the time!], should anything ever be of interest.
 B.W.

[Bullet Whisperer]

   About a year ago I became interested in motorcycles again after having none since 1994 and waded into it to arrive at a new 2015 ( fresh frozen )yellow Royal Enfield Continental GT in March. During that initial itch I found Paul Henshaw's Youtube content and then this forum, and these probably sold me on this bike. I'll probably be improving the machine as it's a pleasure to just stand next to, but the "shortcomings" cause me to itch even more. I've wanted to ask questions and interject to the work I've seen done by you gentlemen during this year, but withheld out of inexperience and could only blurt out in defense of mourning. Your work is, though, is appreciated by the living.

Thanks - it is nice to know I may have played some small part in your choice of machine! Never be afraid to ask questions, however silly you might think them to be - nobody knows everything and most people on these forums share a common interest and are well behaved with each other and don't mind sharing information and helping each other out.
 B.W.

[ace.cafe]

That said I have a spare GT535 crank with a totally worn out big end bearing. The Idea is to shorten the stroke on it and put a slightly longer Jawa Speedway conrod in there with a bearing of the best  quality money can buy. If you are interested you can have the job. I'm just putting the stuff together. The big end on those rods has got the same dimensions as a the stock UCE. I suspect that these Jawa conrods come directly from Carrillo.

Otto,
You could probably get the machining done locally, if you instruct the machinist on what to do.
The flywheel eyes could be welded up with a plug of something like 4140 filling each eye. Then just mark your new centers for the new crankpin eyes on the flywheels, at half the amount of your stroke change, and align-bore some new holes. Finish grind to a .002" interference fit on the crankpin and press in and true. Do a basic static balance to about 65%.
An automotive machine shop with some racing engine experience could do it, if you explain it to him.

[Arschloch]

Thanks Tom, yeah the boring and grinding of the new eyes will take some expensive equipment I don't have. Will see if I find a shop, the other option since those rods are available in 160 and 163 (this would give a stroke of 84mm and exact 500cc) is to use the shorter one and stick with 90mm stroke. With a good bearing especially the quality of the cage it should still give some advantages compared to the stock crank.

[Adrian II]

Custom Billet flywheels?

A.

[Arschloch]

Custom Billet flywheels?

A.

It could well be the case that making new flywheels turns out to be the better option. 

[ace.cafe]

It could well be the case that making new flywheels turns out to be the better option. 

It can be done, but be sure to retain the standard outside diameter of the flywheels because that serves as the oil slosh pump for the gearbox.

[Bullet Whisperer]

Just a point to bear in mind, if having flywheels made and using standard mainshafts. About 4 years ago, I was involved in building what was to be a long stroke UCE engine. The factory big end had failed and the owner had found someone to make a one off crank. The crankcases were also required by whoever was making the crank and when returned to me, the cases [minus gearbox etc] were held together by one bolt and the crank was inside, in the main bearings. I had to split the cases, obviously, to fit all the other internal parts, but that was when I found terrible runout on the mainshafts.
 As I understand it - and you may wish to check up on this - the cranks were assembled in the factory and trued to 'near as', when the slightly oversized mainshafts were ground down to final size, so they would run perfectly true.
 All well and good, until you have a well machined set of new, special flywheels and fit the mainshafts from the old crank ...
 I have a video in my private collection, which shows truly dreadful runout, with this crank making the crankcase halves 'walk' against each other in an alarming manner and, needless to say, if the cases were bolted up, the crank could not be turned.
 I put a video demonstrating this on Youtube, so I could send a link to the owner, who sent it to his crank people, who demanded the video was removed, if he wanted any sort of refund. He got his money back and the engine was never built.
 True story!

[Adrian II]

Bummer.

It's still do-able, but given the above you'd also have to have the original mainshafts out for truing up properly with a bit of corrective machining BEFORE getting the flywheels made. I think there was someone in the UK manufacturing replica JAP vee twin engines a few years ago, their method was that each mainshaft was machined as part of the flywheel rather than being turned-up separately and pressed in, or whatever fitment the originals used. Assuming their machining was spot-on, that'd be one less piece of possible mis-alignment to worry about.

A.

[ace.cafe]

Same problem with AVL cranks. Been warning about that since the AVL came to the US, and the UCE is done with the same method.

At least with the iron barrel models, crank problems were more easily corrected.

[Arschloch]

It would need to be done the other way round maybe. After pressing in the shaft use the race as the reference for grinding they eye as well as finishing the flywheel so it's concentric to the shaft too. 

[jez]

 Hi Paul
I hope for your sake that Mikuni is pretty close on the jetting. Mind you  you've probably got access to a rolling road..... as a last resort.
Covid got in the way of my bringing 24 in for the cam retard. It's put away for winter now so I'll book it in in the spring. I'm really interested to see how much gain you get but as mine has the 32 Amal  I'd expect to have to change carbs to match any head work  on the inlet tract. Is the 34 Mikuni physically smaller than a 34 Mk2? Does it use the standard airbox?

[Bullet Whisperer]

Hi Paul
I hope for your sake that Mikuni is pretty close on the jetting. Mind you  you've probably got access to a rolling road..... as a last resort.
Covid got in the way of my bringing 24 in for the cam retard. It's put away for winter now so I'll book it in in the spring. I'm really interested to see how much gain you get but as mine has the 32 Amal  I'd expect to have to change carbs to match any head work  on the inlet tract. Is the 34 Mikuni physically smaller than a 34 Mk2? Does it use the standard airbox?

Hi Jez, this will be the first time I will have fitted a Mikuni to any kind of RE, although I have experienced RE and other makes with them fitted. I honestly don't know why so many people seem to think they are the default answer to everything - they are good carbs, but no better than Amals and various others, so far as I can see. Maybe it is all down to what you are used to, and personally, I usually know the jet sizes and settings I want for any Amal carb, for pretty much every application I have encountered to date.
 This Mikuni came with two alternative main jets [in Amal bags would you believe], so I just fitted the biggest one, to play safe, the numbers on them not really meaning much to me.
 I haven't asked, but perhaps Hitchcocks are supplying Mikunis due to the apparent lack of Amal MK 2's at present, although the previous pair of 535 GT's I tuned received Amal MK 1's in their carburettor kits, these never having been my favourite Amal, it has to be said.
 As for rolling roads / dynos, it is a long time since we used one and with the Covid situation, it may be a long time before we do so again, but I know the default settings for my builds now, in any case.
 Maybe see you some time, if / when things improve!
 B.W.

[Adrian II]

H's used to sell free-standing Mikuni kits for the older Bullets, VM30, 32 and 34, I suspect the jets supplied would have been similar to those in the Sudco kits sold in the USA, if not identical, so they're likely to be pretty close as a starting point.

Comparing jet sizes like for like between different makes of carb doesn't take other differences in the carbs into account, as I found out. For example, you kindly shared with me your 36mm Amal Mk2 settings for that Electra-X your tuned for H's, though not being able to find a 36mm Mk2 at the time I bought the equivalent size (140) main jet for the Dell'Orto PHF36 I was running, only to find it was a bit lean.

Amal needs to be convinced that there's a worthwhile demand for their 2000 series carbs before they invest in restarting production, but maybe it's too much of a niche market now?

A.

[ace.cafe]

The Mikuni VM series began under license from AMAL.
Same basic heritage.

The things I didn't like about AMAL were the ones with a fixed pilot jet, and the rapid wear out issue, and the easily distorted mounting flange.
Oh, and the high price.

For performance, I expect they are the equal of a VM series Mikuni.

[jez]

Cycle magazine did flow tests back in the day on all the available round slide carbs. Came to the conclusion that it was down to jetting as the rates were much of a muchness