[Aaron Quinton]

Thanks. I finished mine by hand as well. The CNC path left .005-.006" deep grooves in the rough chambers which I also removed. I would have that a 2x difference in surface area of the chamber would matter at running temps.

Originally Posted by john marcella

The finish on my whole head is a cutter finish done by hand not cnc. IMO polishing is just a waste of time.

[john marcella]

Originally Posted by Aaron Quinton

Thanks. I finished mine by hand as well. The CNC path left .005-.006" deep grooves in the rough chambers which I also removed. I would have that a 2x difference in surface area of the chamber would matter at running temps.

Mine were finished by hand cuz I made many changes to everything after I made the motor a 521. So basically they are a hand ported set of heads at this point.

It had nothing to do with removing tool path step over. Waste of time. But if it gives you a warn fuzzy feeling, go at it.