I wish to increase compression in my 1991 B18A1 automatic. Can I put B17A1 pistons in it from a GSR?? and what would be the compression ratio when I do? Also, what about balancing, will the new pistons affect that? thanks

 

Trust me the B17a pistons are not worth it. They only a have 9.7:1 compression in a b17 so in a b18 you would gain next to nothing in compression. The cheapest and easiest way to go is use B16a2 pistons that should bump your compression to the mid 10s.

 

yeah man you would be at around 9 flat with the pistons wich would be good for a turbo. but for na would suck.

 

well how much compression is too much for a 100% not raced street driven AUTOMATIC car? I was thinking mid to low 10's. Also I need to stick with OEM pistons as they are around 140$ for all 4, as opposed to 450+ for aftermarket.

 

also, according to the c-speedracing compression calculator, pr3 USDM B16 pistons give 11.1:1 C/R and the P61 B17 pistons give 9.92:1...This is with stock 3 layer head gasket and stock bore, head, etc. also, what do you guys think about Fel-Pro head gaskets??