83-87 GSX 750 Bottom End on GS 750 Top End??

[Green13]

I race in a division where only 2 valves per cylinder are allowed and 750CC Stock Parts must be used. I am one of 2 drivers that runs a Suzuki (rest Kaw GPZ, LTD ect.) We have been doing alot better but best we have been able to finish is 2nd (6 times in 06) I am looking for an edge and wondered in putting my heads on a late model motor is possible. I think the cylinder arrangement is the same but I don't know about the bolt pattern, oil ports ect. Any body know? Sure would like to get the Kaw's they don't like me running second, and would flip if I could win a couple. Its 2(Suz) against 23(Kaw) right now!

[kingofvenus]

I don't think it would be possible or would help any. Would be probably easier to fudge the rule book a little (Smokey Yunick comes to mind) with what you have, (do they do tear-downs?) or switch to a Kaw.

[brveagle]

Your best bet would be to get both gasket kits and then sit down and compare them. If these apear to line up somewhat, then you might try getting the parts and seeing how close they come to mating together.

[Nerobro]

what advantage are you hoping for by switching to the newer bottom end?

[Green13]

I am hoping to take advantage of the lighter bottom end. I have also noticed that the 83-87 models have higher redlines out of the box. The roller bearing design is tough but a little heavy. I read somewhere that the entire motor on 83-87 GSX750's is almost 30lbs lighter than my motor. What do you think??

[Green13]

brveagle thanks for the excellent idea will save me a bunch of time and money.

[Dan Ruddock]

You also have to worry about piston pin dia. and deck heights. If too tall you could have the cyl cut down or if too short have spacers made. Dan

[BadBillyB]

The reason you cant do this is because you have to use 2 valve pistons with a 2 valve head. The 4 valve 750 has a 2mm larger bore. Even if there was a 67mm (2V) Suzuki piston, you would be well over 750cc ......In my opinion you already have an advantage on the Kaw's....The longer stroke in the Suzuki should allow you to pull out of the corners harder than them. The Suzuki also has 2mm larger intake valves than the Kaw's from the Factory. I would recommend having your 2V cylinder head professionally ported. And also measure your deck height, there may be enough clearance to machine a little off the top of the block..This gives you the best squish area. Also take a little off the head to raise the compression slightly as the 750 only has a 8.7:1 compression ratio......BadBillyB