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The cams have changed a lot since then. It seemed the old cams were 292-296 duration and 106 LSA and the newer cams are in the high 270-low 280 duration and wider LSAs like 110-112 (as far as I know). This gives a lot less overlap for the intake charge to blow out the exhaust. This might be several years old by now.
You calculate overlap by adding the intake duration and the exhaust duration, dividing that by two and then subtracting twice the lobe separation angle. For example, a comp cams 317SSR-8 grind solid roller, for a hemi has duration of 294, 285 with LSA of 108. This gives an overlap of 73.5 degrees.
Last edited by bwdst6; 02/11/11 09:00 AM.
