i know you can put b16 pistons in an ls to up the compresion ratio in an ls vtec. will that also work with a stock ls motor. only asking because i have b16 pistons. so it would be a cheap upgrade if they will work. let me know what you guys think. thank in advance for any replys.

 

the bore is the same, so the pistons will fit, I can't forsee a valve interference problem, as vtec heads on ls blocks with b16 pistons are ok.

 

Yeah, it's been done before and works fine. You may want to use a higher octane gas after the swap, however, as the higher CR will be more detination-prone then the low CR stock pistons.

 

Yeah, dropping in USDM B16A pistons into your LS/VTEC will up your compression to ~11.3:1 if you have a B16A head. If you have a B18C1/5 head your c/r will drop slightly to ~11.1:1. Hope that helps.

 

Are you sure it's not the other way around? B18C (P72 series) GS-R heads yeild higher compression (via smaller combustion chamber) then B16/17/18C specR (PR3 series) heads.

 

this is true

 

Blah... Man, I need to stop posting at such early hours in the morning. I calculated wrong. Acutually...it'll be ~11.3263:1 with a B16/B18C5 head and it'll be about 11.5886:1 with the B18C1 head.

Thanks guys. I don't want to give the wrong numbers.