[serialk11r]

A note on the cams, the reason low end torque drops off with a high rpm optimized cam is because of 2 reasons, the first being lower volumetric efficiency (duration is too long, charge gets pushed back out), and the second being poorer combustion efficiency from higher lift and a lower intake speed. If the second is not a problem, then the high rpm cams should improve fuel efficiency when puttering around town because they will reduce pumping loss.

Usually race cams have higher lift than stock, but I've always wondered what a "medium lift" + long duration cam would do. Higher lift definitely affects charge motion and thus fuel mixing and stuff, but I think the actual flow doesn't really increase after some point because the port itself becomes the main restriction.