Hi, With all the usual talk regarding compression, I was wondering. As an average, what compression can you go up to and still run low test, 87 octane? What's what I run now with my post 73 (I'm not entirely sure what year it is.) How high can you go. I believe that the compression ratio now is 8.5:1
Trevor, There's more to it than that. Generally you can run static compression ratios from 9.5:1-10:1 on pump gas. Your choice of cam figures into this. A large duration cam with lots of overlap will bleed off cylinder pressure, lowering the octane requirement. If you polish the combustion chambers, and top of the pistons thereby eliminating potential hot spots, this goes a long way in reducing the tendency for a motor to experience detonation. Aluminum heads will dissapate heat faster enabling you to run up to 11:1.
