Stroker physics - where the differences are?

It is not nly relevant in strokers... it applies to any design. It means that when you look in a properly matched dynamic engine... To make sure those are defined well... by "matched" that I mean matched in parts and matched to the particular performance window it's built for and by "dynamic" I mean as it's running where it's supposed to be in terms of load and rpm... The right combo will exceed the performance it should be capable of on paper. The phyhics comes into play and things like pressure waves and wet flow characteristics of the head and chamber and flame propogation and that sort of stuff work together to develop more power than it should be able to. We see efficiencies in most drag racing engines in the 115-120% level at peak torque because of these unseen forces workign for us instead of against us. So, the better matched the parts are, the more the cam "will think it's bigger than it is" in terms of power output. The really short version is... poorer ports need more cam to keep the valve open longer when good ports will make the same power with less cam.