Originally Posted by
CBRTRX
Good right up Hurst, but im thinking at least half of your gains from the porting was from shaving the heads the .027
Possibly some of it,. but also remember,.. I ground out the swirl fins and beveled the edges of the combustion chamber around the intake ports. This opened up the combustion chambers a few CC reducing the compression ratio some compared to how it was stock. The .027cc decking was done mainly to clean up the head surface for better sealing and then to combat any compression I might lose from the combustion chamber porting.
Hurst