I have a boosted GSR block with Si head. I originally had Endyn RW pistons in my Si block. When I switched to the GSR block I just used those pistons. So here is the deal, what kinda compression numbers should I be seeing with this setup: Stock Honda head Gasket, Stock Si head, Gsr block with Si 81.5mm Endyn Rw pistons supposedly rated at between 8.06-8.40:1, turbo kit. I did a compression check with the motor hot and cold and here are the results:

Cylinder 1: 155
Cylinder 2: 125
Cylinder 3: 150
Cylinder 4: 155

 

So, umm, are asking if they are off?

 

Im getting around 165-170 across on a built b18c1. Yours is not too low especially since you have lower compression than me. You could just have a leaky valve seal or valve that needs adjusting.