Originally Posted by Twin-shocker
Does the crankcase volume not affect the primary compression ratio then? Not sure whether or not the transfer port velocity might be affected if the ratio was overly high?
not sure if you're referring to it's effect on modern motors or on buls?
on a modern motor with a powervalve, it's not so much an issue. the cranks are stuffed, so the crankcase volume changes become less an issue.. also the gg is shorter stroke...
on the buls, no power valve or reed, i'm sure the primary compression ratio has an effect on the port velocity...