The main benefit of the 750 head is the raise in compression due to the smaller combustion chamber volume 22cc versus 26cc of the 1100 head. The intake runnners are slightly downdraught compared to the 1100 runners.
With slightly bigger runners and larger valves, for better velocity,...the head also works better on a larger displacement engine.....Mike
So I have the option of buying a 89 GSXR 750 head. Do the OEM ones require much porting? If so, who does quality porting (1277 motor, running high 8's hopefully) at a decent price?
A STOCK gsxr head with 350 cams on a 1277 flat top piston will run 8s or you have something else wrong.
<div></div><div>The valves in the 750J/K 88/89 heads although larger than the 750 longstroke heads are the same size as the valves in the 11/12 heads. I've just built an 1186cc Bandit motor using a 750J/K head, which gives a compression of around 13.2 to 1. with a squish of 0.95mm</div>Originally Posted by Suzuki,Mike
I have builta bunch ofGSXR & GS engines using the "dot" heads. I have found it to be a LOT more work to use a domed, high compression piston with the "dot" head & prefer to use it on engines that are using flat top or dished pistons. Also, the cam lift becomes an issue with the "dot" heads due to the valve depths in the head. For ANYTHING over 12 to 1 static compression, I prefer the 1100 heads to the "dot" heads. Ray.
Ok then. If you had a 1277 with Lectron 38's and were going go maybe .370 on the cams, and buy a head to have ported, which would be your first choice, second choice, etc..
Thanks for all the info, trying not to over think this thing
Like I said above, pistons with domes, 1100 heads. Pistons with flat tops or dishes, 750 "dot" heads. Ray.
Well, I have to buy new pistons. It appears I might buy the JE 83mm 15-1 part #132495
<DIV>Dont think the piston pictured on eBay is the ones I'll get, maybe you know the part better</DIV>
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