Originally Posted by Sniper
Not sure what you mean by the valve crossover pocket but the stock combustion chamber is poorly designed for efficient combustion


I know thats for sure.

An OLD flat head racer told me the area over the valve in the head was the Valve Pocket and Valve crossover passage is the portion going over to the piston. The old flat head racer said to never grind out the area above the piston, only in the valve pocket and crossover. He also polished the whole chamber.

Knowing how hard it is to make compression with most of it trying to fill that valve pocket, thats why I think 10 PSI boost would help. 10 PSI should give 25 HP from this 218 CI

Retired, US ARMY 1973-1994
ASE mechanic, Electrical 1994-1997
Retired GTE/VERIZON/FRONTIER 1997-2015


Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.

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