There's a trick I've used with two strokes to measure the clearance between the top of the piston and the top of the chamber.
Hold a length of solder down through the spark plug hole to where you want to measure, and turn the motor over. Remove the solder and measure the gap (how much it has squished).
I expect the same could be done with a four stroke to measure the gap between the top of the piston and the face of the valves.

 

Here in Finland there is a fuel called RE85. There are few bikes that are turboed and have a lot of compression which use this fuel. It just need fuel lines that don't brake from alcohol and bigger injectors then whit regular gas. It can hold up much more compression and boost pressure then normal gasoline. And maybe a thick custom head gasket from steel to get the compression little down.

 

Those springs look like Kibblewhites. Where does it says they have a valve springs for the 954?

 

yeah, there are some STIs here (Subaru Imprezas) making some serious HP on E85. And you're right as far as the gas lines are concerned. Our flex-fuel cars in the States - that's all that is different about them - different fuel lines and modified pumps/gaskets with different o-rings that can stand the alcohol. That's all. Of course, they don't tell you that - they make it sound like the entire car is different!

But, not everywhere here (in the USA) has E85 at the moment. It's funny - the EPA nuts were the ones that started all of the ethanol business - now even Al Gore admit's its worse overall for the environment. Not one gear head was happy when it first came out, but now some guys have learned to work with it (there's a turbo'd 750 gixxer that holds some speed record on E85) when the EPA is second guessing it. It's funny.

I don't know where an E85 pump is near me now. But there is a gas station in town that sells 103 or 108 octane race gas for $8/gal. There are now a few gas stations that advertise ethanol free gas. That's what I try to put in the Bronco whenever I can considering I don't drive it all that much and it has old school fuel lines (1988)

Also, I've heard of guys doing the thick head gasket to lower compression. However, on the 954, how would that affect the motor overall? I mean, physically. One motor mount is on the head, and the other on the case. A thicker one would affect that wouldn't it? Would it possibly warp the motor, or cause the gasket to seat improperly?

 

Maybe - But it'd require taking the head off to remove the valves, then putting it back on to measure, taking it back off again for re-assembly, then back on to make the motor run.

 

THREAD JACK - now complete (Sorry Mobbins!)

 

Here in Finland is one heavily modded na-tune GSX-R 1000 K7 which ran quorter mile last time 9.118 and goes 324 km/h (201,32 mph) standing mile. They're guessing it has about 190 rwhp. It uses very high compression and RE85.

And Motohorhos gixer that you posted at the interesting bikes uses about 13:1 Compression Pistons, RE85 and lot of boost. Hes named it Alcoholocaust

I know one turbo 929 that uses thicker head gasket to get compression little down. I actually sended you picture from it. It's a fighter allso. It has stock internals and max. boost pressure that he has used is 0.7 bars which is about 10 psi. And it has been running for several years.

 

Hey. Idc if its jacked as ling as the info is useful or otherwise interesting to grind the gears alittle. I would absolutly nooooooot run e85 in my 954. Ive watched quite a few shows that show how bad e85 damages your engine. The throttle bodies would deteriorate very quick. Along with a few other internals.

As far as I know you can go thicker on a head gasket without harming the engine. If you look at how the motor is attached all it would really do is give it more of an angle and stress in the frame but not so much the motor. This may not be a good idea for the sake of the frame though. Consndiering how week they are told to be.

 

Yeah, Motohorho's bikes are insane - but it looks like that motor blew up already. Last I saw on CF, he's putting a standard motor back into it. I loved his description of the bike though on FOTY. " Turn the boost down for a "girly" 350 hp or turn it up for an interesting 500+ hp" I can't imagine!

And that's sweet about the 929 (10psi is probably a nice little bit of HP). I was just wondering about the head possibly warping or what not because of the difference in geometry. But I started thinking about what you said Mobbins, and that has to be right. If anything, it'd affect the frame because there's what 16? head bolt/studs on a much more solid piece of aluminum than those motor mounts on the frame that I think are hollow aluminum? Even if they were solid - the frame is hollow. (phfff - who needs the frame to stay in one piece anyways?)

I kind of originally kept enough parts around to build a turbo motor for the 954 (lower compression) in case I blew up the 980 hi-comp motor, or maybe just in case I got bored. But since then, now I'm leaning towards building a stronger motor all around so I wouldn't ever need a second motor. Besides, I can't imagine how hard it's going to be to keep the front wheel down with the built motor(although my new triples weigh 30 lbs!). And I doubt there'd be any fun running the SSSA with a turbo - I'd almost have to go back to a DSSA with an extension if I ever really wanted to use it.



So - slightly back on topic. Mobbins, did you ever figure out an exhaust? Because you're still on OEM right? And did you do your dyno run at 107 degrees on the cams? I know you recently said that at 107 , it was possibly too much. But was it running better than at 99 - or OEM?

 

I went with the hindle headers i had. we made a custom mid pipe and used the gixxer 1k scorpion pipe that i painted black. it sounds pretty damn good compared to the devil i had. the only reason i thin 107 is to much is because it tends to take some throttle to start more like a track bike. which is fine with me but everyone else thinks its bad haha. they are used to their stock bikes kicking on first touch of the button. with the new dyno we only got 2 more hp but then again it was 35 degrees hotter outside haha.

i get alittle bit of hesitation between 5-6k rpms. which is actually why the exhaust valve is there. to help creat alittle back pressure. so im hoping to find some crimped headers sooner or later to help. the serpent exhaust from micron or a full akra. is what i reallly want. i would do a custom pipe like mv agusa if i get serpent headers though.