[gashousegorilla]

GHG, would a 10.3comp ratio be streetable on pump gas? Or would backing up the intake cam be better all-around for street use?

  10.3 in the Bullet UCE motor has been fine for me for YEARS  without concern of ping... no matter how I phase the Cams.  I do Use super though as a precaution... although it has not pinged on regular.    10. 3 for me .. in my findings with the bullet 500 motor has been the tipping point as far as power goes.   Lower compression, less power.... HIGHER compression, less power.   I think one reaches a point of diminishing returns as far as compression ratio goes.... Over coming TOO much cylinder pressure becomes counter productive me thinks..

  Also bare in mind , you kind of want to match your timing curve for the new compression ratio and Cams if you can.   I am at anywhere from 4-7 degrees ADVANCE in my curve , probably all in at around 2500 ? .... still no ping.    We don't really know for a 100 percent sure just what the stock timing curve looks like on a EFI UCE.  But I THINK, it's about 27-28 degrees full advance ?  So that puts me at about  33- 35 all in... I hope ! LOL ! 

 Re-phasing the Cams , or retarding the intake Cam, does different things depending on the Cam profile... but generally it moves the power band up 300-500 rpms .  Compression readings doing a static test will generally be lower .... however dynamic pressure may greatly increase because that valve is opening later as the piston is farther down the hole.... it opens when there is MORE suction being pulled in. 

 In our case retarding the STOCK intake Cam that one tooth... or about 4.7 degrees of crank rotation does WONDERS.  Mostly because of it's very conservative .. tractor like..  profile.     Cripes.. I don't think the intake valve opens until AFTER  TDC !    You may actually see a RISE in pressure doing a static test ... about 10 psi in my findings. But anyway... doing this on a stock cam worked quite nice I have found.   No loss in bottom end , and BETTER top end I felt..


 

You guys know, of course, that (insert place name you wish to defame here) is where they invented the tooth brush - anywhere else and it would have been called a teeth brush...

  Trenton ?

[dginfw]

  ...In our case retarding the STOCK intake Cam that one tooth... or about 4.7 degrees of crank rotation does WONDERS.  Mostly because of it's very conservative .. tractor like..  profile.     Cripes.. I don't think the intake valve opens until AFTER  TDC !    You may actually see a RISE in pressure doing a static test ... about 10 psi in my findings. But anyway... doing this on a stock cam worked quite nice I have found.   No loss in bottom end , and BETTER top end I felt..

Interesting.  I wonder how much a Continental GT with the "basics" already on it (intake, exhaust and PC-v) would gain from tweeking the barrel for proper squish AND changing the cam timing? Those 2 things can be done by a knowledgeable owner, and might be just the ticket for cheap performance gains

[gashousegorilla]

 QUITE a bit I would imagine.  Same part number on them GT Cams as on the Bullet .         And BTW... You guys are squish and zero decking crazy I personally I think.  But whatever     Increasing the compression ratio by doing it to a certain extent ain't a bad thing.   I run the stock deck height, and 36 hp and 38 ft lbs. at the wheel don't lie.   Squeezing shit down THAT much I actually lost power.   So, to each their own. 

  But... yup .  Very easy and cheap things to with intake, exhaust, and playing with the intake Cam.    You wanna get crazy ?... pull a section or two out of that head gasket to boost the compression ratio a bit .  You don't have to run your barrel off to a machinist.  Unless you want to get a bit more compression ?  Crazier still ? ... throw a flat top piston in there instead of that soup stock bowl piston ?    and etc and etc.    Pistons are MUCH cheaper and easier then combustion chamber redesigns.     And we have done both... just sayin' .  There are plenty of things hat can be done in steps or stages, and have fun doing it along the way.

[dginfw]

I have a new, in-box AVL piston in my garage just in case I get another C5....I'm  ready.  Got it  cheap on close-out lol

[gashousegorilla]

  There you go !  Wise move I think and it works very nicely.   Really don't know why they didn't put those flat tops in the UCE either ...  Emissions I guess  ?  Same damn piston except for the dish.    The UCE motor is a good damn motor... I've beatin' the piss out of mine.   WAY over built in a lot of ways compared to the earlier motors I think.    Gawd !... bikes with 50 k miles still putting out what they did at 1k miles.   Very little wear found inside inside and etc..    Sure we get an anomaly here or there  that we've seen ?   But I believe the motors are NOT the problem with these bikes.

[Bullet Whisperer]

I agree totally with what GHG says. Although I didn,t actually measure the C.R. of the CGT I tuned, I had to shorten the barrel by 1.5mm to get a 1mm squish clearance with a base and head gasket in place, so the C.R. has to be the other side of 9:1, at a guess. What I KNOW, is the C.I. motors in 350 and 500 forms really wake up when they hit 10:1 and I usually retard the inlet cams in these by a whole tooth [18 degrees] and get excellent results, although I fitted the Hitchcock cams to the CGT timed to the marks and it went well enough. Basic unleaded seems to work fine for me.
 The only downsides I have spotted with the UCE engines to date is their standard cams seem to have very short timings and the timings are not ideal. Also, there is no crankshaft 'timing pinion' - the gear teeth are cut into the mainshaft, so no 3 way pinions for these and if anything happens to damage those teeth, it will be a full engine strip and a crank job to put it right 
 B.W.

[Otto_Ing]

I've found the CR to be about 8.5 in the stock GT engine. Fixing the squish gave a CR of 9.0.

GHG: Maybe the deck hight is different on a 500 but on the 535 removing gaskets is just not enough. Could be another improvement RE did to that engine besides lightening the crank.

[dginfw]

Maybe some cost-cutter at RE made the decision:  "we can bore the barrels out to 535, or we can set a good spigot height...BUT WE AIN'T DOING BOTH"   
Lol

[gashousegorilla]

I've found the CR to be about 8.5 in the stock GT engine. Fixing the squish gave a CR of 9.0.

GHG: Maybe the deck hight is different on a 500 but on the 535 removing gaskets is just not enough. Could be another improvement RE did to that engine besides lightening the crank.

  I have found generally from different 500 motors that I measured, the compression ratio is in the 7.75- 1  area. Unlike their advertised  8.5-1 , where I assume all they are factoring in is cylinder volume and combustion chamber volume.  Discounting deck height, dish volume, gasket thickness and etc.

 I does sound like the deck height IS different in the GT's ... you guys have been inside them.  And certainly not the only bike or motor out there with a piston outside of the " optimal hot rod Chevy 450 four barrel squish band".     The 500's are generally a little south or north of 1 Mil down in the hole , BEFORE the stock head gasket and head goes on.  Removing a section or two of head gasket may not be "enough" on the GT.... If "ALL" your concerned about is getting a higher compression ratio and tightening up that squish band.   Discounting or giving up things like chamber volume and flow and etc.   You just want... In my humble opinion, and without over thinking it.... an area small enough to force out the trapped reactive mix at high speed which is caught under and in between the head and the edge of the piston... And that's it.    I err on the side of a little "loose" in that regard, over a little tight in that regard.    A little too "Tight" , and instead of that reactive mix being forced out from under things... It may crack off and burn under there instead.   I and I really don't think there is any ONE fixed measurement that works for ALL  motors and all combustion chamber designs.    All things have to be factored in I believe.   Your piston crown is going to effect the burn.. your chamber shape is going to effect the burn and etc.   

  Correct me if I'm wrong... I think I remember in your case ?  You adjusted your deck height at the barrel ?.. increasing your compression ratio by doing so.   AND you also un-shrouded your valves, increasing flow AND increasing chamber Volume .   Is that correct ?  If so, that's pretty damn good thinking.     And I think you got about 25 at the wheel  with the customary intake and exhaust mods ?   That's pretty good over a stock bike But If so, that is but ONE way to do it I think...

I agree totally with what GHG says. Although I didn,t actually measure the C.R. of the CGT I tuned, I had to shorten the barrel by 1.5mm to get a 1mm squish clearance with a base and head gasket in place, so the C.R. has to be the other side of 9:1, at a guess. What I KNOW, is the C.I. motors in 350 and 500 forms really wake up when they hit 10:1 and I usually retard the inlet cams in these by a whole tooth [18 degrees] and get excellent results, although I fitted the Hitchcock cams to the CGT timed to the marks and it went well enough. Basic unleaded seems to work fine for me.
 The only downsides I have spotted with the UCE engines to date is their standard cams seem to have very short timings and the timings are not ideal. Also, there is no crankshaft 'timing pinion' - the gear teeth are cut into the mainshaft, so no 3 way pinions for these and if anything happens to damage those teeth, it will be a full engine strip and a crank job to put it right 
 B.W.

    Good stuff !!  Getting your hands dirty, tools and bikes all over the garage, trial and error and getting it out on the road and beating it !     A little sacrificial lamb thing going on with that idler gear aye ?    Maybe that is why they decided to go with the eccentric spindles and one less gear to avoid any losses with the extra gear ?   OR, they were just being cheap !  LOL !    I'll tell ya... I always set that cam lash slightly loose.   SCREW any noise that may arise !    I set those Cams so there is nice and easy, sliding  them in and out between all the gears teeth, AND in ALL positions.   With JUST a little perceptible... slightest of noise when grabbing the gears trying to shake them.

[Otto_Ing]

IMHO when setting the lash what many people miss is to check it all 360deg round. A slight concentricity issue between the bush and gears and it gets jammed.

Fixing the squish, airbox, exhaust and unshrouded intake valve gave 26rwhp SAE corrected. The squish of course was most beneficial to the burn with a cleaner combustion, low rpms benefitted.

[dginfw]

Just an update.... Hitchcocks was kind enough to sell him some replacement cam spindles at a reduced price, and someone from RE USA will be on hand to assist the local dealer (who did not do the initial install) to install the replacement parts.  Hopefully everything will go smoothly, and no damage was done to the case when the cam spindle spun in its seat.
After hearing the dealer's side of the story I'm pretty sure the small independent shop that did the install did not set lash correctly.  Moral of the story- just because a technician is familiar with Japanese bikes or American v-twins, they can still mess up something as simple as an Enfield motor if they don't know what they're doing.

[mcraigor]

I'm unfamiliar with engine modifications so this may end up being a silly question.  Do you install the performance valves with the performance cams?  Can the cams be installed but leave the stock valves installed?

[Otto_Ing]

I'm unfamiliar with engine modifications so this may end up being a silly question.  Do you install the performance valves with the performance cams?  Can the cams be installed but leave the stock valves installed?

The stock valves might work but the springs will sure need upgrading so that the valve gear can safely follow the more agressive cam profile.

[Narada]

It is encouraging that someone from RENA will oversee the repair. I hope that means an experienced hands-on mechanic.

Are the spindles being replaced? I would be interested in learning thier process for that!

Maybe a report could be posted?

Things are looking up. That was one scary meltdown! And a scary mechanic who caused it. 

[dginfw]

I'm unfamiliar with engine modifications so this may end up being a silly question.  Do you install the performance valves with the performance cams?  Can the cams be installed but leave the stock valves installed?

On this bike, the owner had already upgraded the valves,  but I have heard of others that did not and just did the cams.  The stock cams are pretty mild on these bikes