http://www.jepistons.com/pdf/2...a.pdf

If I would put an B18C1 9.8:1 piston in an B18C5 engine I will get out an CR of 8.6:1, is that correct?!

But the quench area would get a bit more, right?

 

check out c-speedracing.com and calculate your compression

 

nice programm, but when I insert all the specs for B18C5 engine at http://www.jepistons.com I get out 8.46:1 cr and not 9:1 cr?!

 

werid it should be correct i know it works fine for the stock pistons..

 

yeah, I tried with stock pistons too, it is correct, but when changing to another Piston Dome Displacement (cc per piston) from the aftermarket piston homepages ...the numbes are way off from Wiseco or JE homepage.

 

Everything else being equal, a piston that yields 9.8:1 in a b18c1 will net you about 9.6:1 in a b18c5 due do the larger combustion chamber volume. They both use the same bore and stroke so that's not different.