Compression Question

[75bird]

I have recently aquired some 64cc combustion chamber heads, which on my car (sbc) will boost the compression to 12:1 is this too high for pump gas? I think it is but have any of u ran this compression on pump gas? My father told me it would ping and backfire but i wasnt sure!

[Vegas]

Man My B20 vtec ran 93 octane at 12.5:1 commpression with no detonation or spark knock. Im sticking the B20 back in my car at 13:1, and I am about to see if I can tune it to run on 93 so I can drive it to Little Rock.

[TRedlineCRX]

My bike is like 13.7 and runs on 93

[specvmike]

with tuning, 12:1 shouldn't be too much of a prob on pump gas

[StreetLethalCamaro]

Your dad is right about the pinging. 12:1 is too much, if you plan to run it on pump gas. If you just plan to putt around town and fill it up with race fuel on race day, that could work, but you'll have to retard your timing and go easy on it when running the pump gas.

btw, i'm assuming you are running a carb?

I'd say that 10:1 is a good street compression ratio for a SBC. It's a nice middle ground. my .02