Roger,
like I said before, this is your area of expertise not mine.
I think your incorrect that any of the other things I suggested on this thread wont work or set the world on fire, just most of them:). IMO you have to sometimes put things out their to stimulate ones thought process.;)

I still feel that increasing the compression with the right combination could be a viable route rather than increasing displacement. The combination is the key to this. But in the greater scheme of things its the doing that fun.
jeff

Jeff

I'm covering the bases with a 1200c crank & block and HC pistons and then balance it. Top end .....larger valves and flowed head and lighten valve train and a med grind cam.

FYI.....the 1100 and 1200 rods are the same length......but a longer throw on the 1200 crank should make more power with the slightly longer time the piston will be at TDC and added CC's it all adds up a little here and a little there.



1100 rod & piston on right

http://forums.pelicanparts.com/uploa...1127614951.jpg http://forums.pelicanparts.com/uploa...1127615058.jpg

Moybin, clearly the compression is to high for a turbo, but if we are putting in aftermarket pistons, it wouldnt be much more effort to put some dish into the pistons.


Joe, I believe you are mistaken there. With the rods being the same length and the stroke being longer (i assume it is longer, no?) then there will be less dwell time on the 1200 vs 1100 engines. When you increase rod length without changing the stroke you then are increasing the dwell time.

Bigred455

You are correct I mistook crank throw for rod length......how high can you move the pin up it's almost in the rings now?

Bigred455

Just taking things as stated. If you are going for custom pistons why not have someone create custom billet aluminum rods?

I'm just going back to my early years with engines. The R1100S arrangement is not a Chevy 283 or Ford 289 with gobs of potential for modification and improvement. This is an engine that has been through no one knows how many iterations on a computer.

There is room for improvement, but I would go looking at such things as the CF wheels, mounted with custom titanium brake rotors, ditching the cast & welded aluminum engine frame with something of titanium or chrome-moly steel. That's the money-is-no-object route.

I doubt that 100 pounds could be removed from the gross weight of the vehicle as delivered to the dealer, but no one has actually tried. After all, there are a lot cheaper ways to get horsepower; mainly by buying a different brand/model of bike.

And I agree that the building and tinkering can be a lot more fun than the actual finished product.

Joe,
I am not sure how far up into the ringland you can put the pin w/o causeing to much decrease in reliability... I would have to ask some more knowledgeable sources.

An aluminum rod might be the trick, but I don't know how much warm up time would be needed on an oil cooled bike to keep the longevity of an alumin rod alive.

On a similiar note..... does anyone know the stroke, crank rod journal and rod pin sizes?

Coupla comments.

The turbo is still a viable option, even with the stock pistons and CR. The goal is not to make 300HP here just a nice little increase. 5 PSI will do that giving about a real world 20% increase in both torque and HP. Bob Behns expertise in turbo sizing will yield and installation that would have almost no turbo lag, 120 or so HP and probably 82 to 85 lb/ft of torque. That would be a really nice combo and no real weight penalty.

You could get within range of that by bumping the compression and going with some cams that were designed for the increase. A little help in re port matching and a good, extracter style, exhaust. The caveat is fuel availability but, that applies to the turbo as well. As the price of lunch is the same for both, not free.

JonyRR's comments in re the clutch bear some thinking as well. My experience with my turbo K100 tells me that the stock clutch won't put up with a 20% increase in power.

> I think your incorrect that any of the other things I suggested on this thread wont work or set the world on fire

I dont' recall saying that they wouldn't work. Depends what you mean by work, I suppose. But it remains a fact that none of the things you mentioned will set the world on fire.

It also remains a fact that apples-to-apples, compression alone will do less than compression and displacement together. Not a difficult concept, really. And remember, people that have done most every one of these tricks (intake, filter, portwork, exhaust, dualplugs, FI work, hi-comp etc ALL Together have netted about 15hp/20%. That's a nice bump, but even collectively, hardly incendiary. Individually, no one mod does much to these.

All that having been said, I'll probably be doing the hi-comp piston route myself. The rationale is I'm more worried about reducing vibes than bumping power, and the small, stock-displacment/hi-comp pistons are lighter than stock or oversized aftermarket pistons. I'm making it smoother, and if I get 1-2hp extra, cool.

jeff~
if you follow the engine mod route, remember that the biggest key to success is to accommodate as many components on down the line (clutch, crank, this, that) as possible. right from the beginning.

a bigger fist requires a stronger wrist, which needs a better elbow that relies on a beefier shoulder, etc...

(and sometimes the whole thing ends up being just a giant pain in the neck and you wanna cut the hand off after all).

i had a russ collins built big-bore suzuki (1153cc? somethin' like that). it was supposed to be an endurance road race bike, but was actual a ground missle in disguise.

as the monster motor kept eating things (motor mounts, swingarm bearings, overheating, boiling carbs, etc), we kept chasing it and beefing up the parts.
we finally had to admit defeat when the rear sprocket became the weakest (strongest?) link. even with big, fatty hand-rolled spokes, the sprocket kept tearing out spokes.
it was the pre-cast wheel days and there was no good solution we could find.
we parked it permanently and started over with a slightly smaller hammer.

once you pick pistons, super-size all the other big parts that help make it go.
once you're convinced you have everything beefed up, hold up two fingers. that's usually how many surprises will pop up.

why not just ask Eron what he's done, and do that. AFIK he's done as much, if not more to his S than anyone that i can recall.
L

I believe ezrider out of portland, or, had done pretty much everything jeff is contemplating; last I read he went the 1136CC cylinder route, with BBpower 12.5:1 pistons and the matching cams. Haven't heard much from im lately but I hope he didn't grenade it. I'm of the opinion the weak link after some modding is the clutch (as brad explained, once you yard some mo 'powah out, you will start chasing the newest 'weakest link'). I'd say it's in the realm of practicality to do the 1136 cylinders and more compression with BBpower pistons, or spec the pistons and have ross or venolia (two of the best custom piston makers in the world) do some one-offs...then I could call 'em up and buy the same things you paid the tooling and setup price on, jeff *grin*.
have the SJ dudes do some portwork on the heads (or that guy that bobby w. knows in georgia).....then figure a power commander of techlusion to get the 'jetting' right.
I still say the RB turbo setup is the best bang fore the buck, and with his specced injectors and aux. ECU it should be as 'turnkey' as any project like this can be.
I've molested any number of perfectly good mechanical devices in my day and they all, every single one of them, took more time, effort and money than I figured on going into it (that's part of the bizarre appeal).
shovel said it best...'spit-shining a turd', but still a rewarding experience if you like to tinker. I'm leaving mine alone until I get a more robust clutch setup in it.
I recommend matching the intake boots to the cylinderhead; there's a huge discrepancy there (at least on mine there was) and perhaps gently blending the exhaust ports toward the step in the pipe (you have ground out the welds and added he SJ velocity enhancers, right) and perhaps having RC engineering test and if possible flow-match the injectors. ro replace them with hi-po units.
There will be no HUGE gains here, but an accumulation of small gains sometimes adds up to something worthwhile.
Really, spend the money on a PCIII and dyno time to get it dialled in to a gnat's azz; I'll bet lunch there's HP in there you haven't gotten yet without changing any mechanical bits...