More HP with a cast crank? I am more prone to think that the lighter weight of the casting would put more HP out of the crank as you accelerate up in RPM's....IF you use lighter pistons and rods to match the lighter cast crank. I can't quite see where the casting not flexing as much (if indeed it does not flex as much) would make more HP....If the crank flexed a bit under the load from the rods, then that lost motion and energy would eventually come back into the crank output as the rod pressure dropped.
