Went on Nippon Power's website and found these two thinkess for Cometic headgasket:

.025 inches
.030 inches

How do they compare (thinkess) to stock?

Is the .030 like stock on the .025 a little lower? How much lower is the .025 from stock? How many pts would that bump up the compression?

Adam

 

On my B16A2, I measured the gasket to be .026", but that was after it came out of the car. I think they compress just a tiny bit after torqued down. I think a new OEM gasket is around .030". Every .010" reduction in gasket thickness yields about a .3 point increase in compression with a stock bore B16/B17/B18.

Sonny

 

http://www.c-speedracing.com/howto/c.../compcalc.html