RE: Questions about engine rebuild and machine shop work

Chris King wrote:
"Flat top pistons will give you a theoretical 9:1 compression ratio. I
have heard that you can go up to 9.75:1 and still use pump gas."

That's cutting it fine... I have close to 10:1 compression in my Twin Cam
engine, and that was supposed to be fine for pump gas. It is not. Now do
keep in mind here in CA the best pump gas is 91 octane, and the formulation
is such I suspect gas in other states is actually better... and cheaper?

I would personally not go over 9:1 compression for a street engine running
on pump gas.

JLC