GS1100 Engine Specs Needed

[Guest]

I bought an engine and a rear swing arm assembly, including the drive shaft shocks, wheel and tire, fender and tail light. The engine has real good compression and from what I'm told, the bike had low miles on it. The upper part of the bike caught fire so the coils and ignition wires are fried, but it doesn't look like the fire got any further down. The guy I bought it from cut the bike up for a trike project then changed gears, so I got all that for $100. I have a picture of the VIN from the head tube, and I've got the numbers from the engine. So I've decoded it to be a 1984 GS1100, shaft drive.
I'm going to put a turbo on it, so I need to know the compression ratio to decide if I need to shim the head or not. I've seen 9.5 to 1 and 8.8 to 1 for this engine, but I can't narrow it down further.

Does anyone know what the actual CR is?
And as a bonus, does anyone know if this engine will take 15psi of boost with no internal modification? I will use an intercooler because I don't want any more heat being pumped in that absolutely necessary.
The engine is going on an all wheel drive 2 passenger reverse trike, so I'd love to get 200 reliable horsepower out of it, but if that's too ambitious, I can live with less.

Thanks

[Rich82GS750TZ]

I have no answers for you, but this sounds like an ambitions project that will be a lot of fun to follow. I hope you post pictures along the way.

Oh, and welcome to the forum.

[rphillips]

Looks like the 8 valve 1000's were 9.2 & when they went up to1100, in "82" dropped to 8.8. I know Suzuki started welding the crankshafts on the 16 valve 9.5 compression 1100 eng.'s, in I think "83". I don't remember Suzuki welding the crankshafts on the 8 valve engines, they may have, but I don't remember it. Please check, 15lb. boost without a welded crank would not be a good idea. Just my opinion.

[Nessism]

The secondary drive gears on the 1100G engine is a weak point. I doubt they would survive 15 psi for long.

[Rijko]

Are you sure you have the right engine for what you want ?

does anyone know if this engine will take 15psi of boost with no internal modification?

I would not try that .. it will blow up.

I'd love to get 200 reliable horsepower out of it

Just by adding a turbo ?
No .. this kind of engine can take some extra horses, but nowhere near that without expensive modifications. Welded crank may be in there, but i would guess on
clutch and gear modification, oil pump upgrade, cylinder studs, new pistons, flowed head, etc etc.
Find the right turbo and setup and hope you don't need another set of
pistons while getting there. Again, real expensive option trying to get that
engine so powerful and reliable, too.

I think if you're looking for that kind of power, it's way cheaper and simpler
to go with the tried and tested GSXR engine.

[WisdomWarlord]

This trike project is a razor thin budget, so it's probably not the engine I want, but at $100, it's the one I've got. The upside to how this thing will be built is that I can change engines to something different with not too much headache, as long as I stick to air and oil cooled engines. Liquid cooled adds more complication and weight that I care to deal with. If I'm stuck with close to stock, I may skip the turbo and just enjoy the 90-ish hp it's got stock. In an 800lb machine, that's still a lot of fun! Maybe I need to look into a smaller lighter gsxr engine for future engines. Right now, I don't know enough about what options are available to speak intelligently. I know I want reliability and 150-200hp in some to that doesn't need constant repairs. And I can afford! Lol

[Rijko]

On a thin budget, i think stock is the best option.
As you say, that will be fun.
That engine is sturdy and has a lot of grunt.

[Steve]

I am most curious about the "all wheel drive 2 passenger reverse trike".

Some people consider that the driveshaft arrangement for the single rear wheel robs enough power, I'm curious about the transfer case that will direct power to the front, then the differential that will split it between the front wheels.

And to keep all THAT under 800 pounds? Even with an unlimited budget, that would be rather ambitious.

.

[gs11ezrydr]

A turbo on a shaft bike Might be a bad combination, Consider there is approx. 10% power loss going through the output shaft gears..And a lot of load..

[Grimly]

Another thing to consider is that Suzuki seemed to be reluctant to power any of their shafties with any more than 120-ish horses, so the shaft system obviously has its limits. I don't see the gearbox being fragile, but I could be wrong on that.

[GregT]

It's not the gearbox that's fragile, it's the output gear pair. Keep it stock - and even then those gears are the weak link.

Boost....Our roadrace GS1000 has a welded crank in it which came from a guys turbo project, It had a terminal meltdown at 17,000miles on one of the occasions he dialled up the boost.
I believe he usually ran it at about 7lb - quite reliably. Took it to the drags a couple of times and wound up the boost.....

In a trike, I'd use the 750 oil pump gears and fit an oil cooler.