Quote:
Originally Posted by sendler
Power band and over lap is not just a matter of cam timing. Cam duration is the same regardless of where you time the cams and could only be optimized for a lower rpm with a re grind. Changing the timing could help though.
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Sure, but the fact is that the lift and closing points appear to be much more important than the overlap or else car engines wouldn't be making much power. Scavenging helps but the closing point is matched to the intake harmonics which has a bigger influence on volumetric efficiency.
By moving the cam the idea is obviously not to optimize it for a lower rpm, it's to reduce the negative effects for efficiency and combustion stability at lower rpm of having large overlap (which possibly further trades off more low end torque), and possibly increase top end power (would depend on specs).