i was wondering about the diffrence from your typical casted piston surface, and the forged polished surface of a piston. I would image the polished, ultra smooth surface would help control detonation.. but what else.. better blast.. what....

 

 

i'll post a picture, maybe that will help.

 

I am no piston guru, but from what I read, the top of the piston should be as smooth as possible. It should be free of burrs, and any sharp edges should be sanded down. Also, I read that polishing the tops of the piston helps. Anything to keep hot spots down (sanding sharp edges) and keep carbon and other risiduals from bonding to the piston top (polishing), helps to prevent detonation.

 

Even some new forged pistons can go through the sanding and polishing