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Old 03-22-2005, 07:20 PM
Excaliber Excaliber is offline
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Default Advance you retards!

I have a 427 S.O., high rise heads and was faced with the same problem. WHAT cam and how to decide?

Interesting comment concering lift being a ratio of valve size, I never heard that before. Cam profiles are EXTREMELY complex, a worthy goal to research deeper into it.

I based my basic cam profile on: Typical cruising rpm because I wanted primarily a "street" application. I wanted a nice torque curve in that rpm band and was willing to give up so high rpm performance. My rear gear at 3:31, top loader, 60-65mph, 2800 rpm or so. Then I looked at specs that fit that profile. Like 1800 to 6200 rpm range kind of thing. Then I checked with George at Gessford and told him the range I was looking for. We talked about what I USED to have, how it worked and what I was looking for now, my heads, compression, etc. HE then picked my cam based on his experience with MANY side oilers in Cobras.

I THOUGHT my old solid roller would be a high lift cam, NOT SO! Rollers tend to have a LONG duration over a high lift. This stuff is complex man!

ADVANCE the cam and move the torque curve down, more torque at lower rpm. RETARD vice versa. I degreed my cam "just to make sure" it was what it was supposed to be. I set it "straight up", but here's the kicker. My Comp Cam paperwork says the cam is ground with a 4 degree advance built into it. If it's GROUND that way all ready HOW can it be considered 4 degrees advanced? Advanced from WHAT?

I'm thinking they use the same basic lift and duration for several cam "part numbers" and what they "alter" is the amount of advance or retard ground into the SAME cam when they make it. Thus the "torquey model" is really the "high rpm" model with a different "degreed centerline"? Of course lift/duration would probably change (or would it?) with a new centerline, making it impossible to know if it's really the same cam profile or not!!! There so sneaky those cam guys!

Last edited by Excaliber; 03-22-2005 at 07:38 PM..
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