just wonder how i would go about calculating the compression ratio of an engine with stock head. im trying to figure what size piston would be best suited for a turbo or blower applications. i did a search and found some genral background of pistons. just would like to know how exactly could i calculate the aprox. ratio. i know i want to get pistons <~-10 and id like the cr to be around 8.5:1. also what does compression hieght mean? any input would help.

 

With -10cc pistons with a .040" compressed gasket you will be around 9.3 CR. This is with the piston-deck height .002". If you went up to say a .050" it would drop it to about 9.1 CR. A -15cc piston will give you about 8.4 CR with the same piston-deck height and a gasket thickness of .040".

 

just a quick note. with this kit:
http://www.lethalperformance.com/pag...mpression.html

the pistons are -28.50 but the compression ratio is still about 9:1. is this because the rods are not stock so it changes?

 

http://www.rbracing-rsr.com/compstaticcalc.html

 

ahhhhhh just what i was looking for...thank you