What is so great about “Porting by Hand” verses CNC porting?
Either method can be effective. The bottom line is these motors are not high rpm units and the design limits the upper rpm limit. We need to exploit the torque they can produce and have effectively done that with “velocity” ports. These ports give the motor what it wants and needs based on the bore, stroke, and cam choice. Actually this efficient high velocity port goes a few steps better and raises volumetric efficiency by concentrating on emptying the full exhaust charge early in the cycle and optimizing Intake flow when the piston is at maximum draw also early in the intake cycle.
