Originally Posted by
sherwood
no, i can have a 4cyl that runs at 2k on the highway, power output and rpm range have more to do with cam profiles than anything else.
Sorry, you are off there. Power is a key factor, but a large displacement motor does not need to spin as many RPMs to do the same work that a small displacement one does. The motor spins the same regardless of the cams, only where in the RPM band the power is and to a small extent how much peak HP will be made, is determined by the cams. Cams are along for the ride, they do not affect the engine RPM. This is fact, not theory.
the reason a 4 cyl USUALLY has shorter gearing is becuase of them making the bulk of their power up in the high range, but that has to dow ith alot of things, including rotating mass, air restriction, you name it
This is right and reinforces
my point - you NEED more RPMs to achieve the power because there is less torque to do the work.