You are just not understanding the engine dynamics of how rod length affects the characteristics of an engine. Longer rods slow down piston velocity at many spots thru its travel up and down in the cylinders, thus reducing the torque, especially at lower RPM where it is more noticable.
Hi Ronald . . . panic doesn't come around here much more any more - but his victory tech paper on the effects of rod-ratio is quite instructive:
Rod-Raitos
