VP race fuels

[J Kuchel]

Ok does the static comp. and the cranking comp. make that much difference? The static is 9.69 to 1 but it has alot of cranking comp. due to the camshaft profile.

[Dave Cook]

Originally Posted by J Kuchel

Ok does the static comp. and the cranking comp. make that much difference? The static is 9.69 to 1 but it has alot of cranking comp. due to the camshaft profile.

If you spin it many RPM's, your octane requirement does go up, but I agree, you are probably wasting $$ and performance potential by running more octane than you need. Octane is, in simple terms, the measure of the resistance to ignition....if you are running race fuel in a low compression engine, you have to advance the timing to recover the performance you may get with lower octane and less ignition lead.

B.T.W., my engine is 15.01:1 static, with a fairly long duration flat tappet cam. I run any generic "110" leaded fuel that is available, but never spin it over 6500 RPM's, run it cool, (130 at the line) and run it fat on the carb jetting.