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Hey Guys,
I have a new engine for a street car that's sporting 11.25:1 compression. It's a iron headed 440 with stock intake and exhaust manifolds, running a pure stock cheater cam and 800 avs edelbrock carb. Stock reproduction coil and factory dual point converted with pertronix ignition kit. Total timing set at 38.
On initial break-in we mixed 110 octane with 93 so it wouldn't ping. I was wondering if any of you guys have had experience mixing race gas with premium. Someone told me the stock coil doesn't put out enough voltage to properly burn the race gas and I should try and run it on 93 if possible, stating that with alcohol added it is more like 96 octane. I'm not up on that stuff, so not sure what is a old myth or real. I would appreciate any input from guys that have experience mixing this stuff.
I don't mind adding race fuel if needed for it not to ping. I want to understand better how they act when mixed and if the stock coil is a limiting factor.
Thanks !
If you mix 50 /50 of 110 and 93 you will end up with 102 and that should keep you out of detonation - even at 38 degrees timing. If you have a fuel seperation issue, you got water in the fuel, which will cause the ethanol to fall out of suspension. I have raced with that blend in a 11.52:1 motor ( 195 cranking compression ) with no problems. I might add I was running a pretty tight quench though ( .038").
Last edited by Crizila; 11/17/11 12:23 AM.
