[hurryinhoosier62]

I’ll go with what Ken Crocie says: one point higher than what an engine with iron heads can run without detonating. Example: if you are running 6X-4 heads milled to 85cc on a 455 with a 9.5 to 1 c/r and a cam that allows for cylinder pressures not to peak above 180psi you can safely run a 10.5 to 1 c/r with 85 cc E-heads. The “421” I’m in the process of building for my ‘64 Catalina will have a static c/r of 9.98 to 1. I may give up a bit of top end power, but engine longevity is worth it in a street engine.

[torqjunki]

That was to hgerhardt.

[Steve C.]

Calculate Over Lap and Lobe Separation Angle

http://www.wallaceracing.com/calc-cam.php



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[65 Lamnas]

Originally Posted by hurryinhoosier62

I’ll go with what Ken Crocie says: one point higher than what an engine with iron heads can run without detonating. Example: if you are running 6X-4 heads milled to 85cc on a 455 with a 9.5 to 1 c/r and a cam that allows for cylinder pressures not to peak above 180psi you can safely run a 10.5 to 1 c/r with 85 cc E-heads. The “421” I’m in the process of building for my ‘64 Catalina will have a static c/r of 9.98 to 1. I may give up a bit of top end power, but engine longevity is worth it in a street engine.

Depending on which chamber you use…