tommypenguin

I purchased a set of new pistons from another forum member and received them and noticed a small ding in the ring land on the side of a valve relief. It looks minor but these are going in a boosted application am concerned im asking for trouble. Thoughts on whether I should return the pistons.

LLLosingit

iTrader: (4)

If you're talking about the little ding on the top edge of the piston ( I don't see a ding in a ring land) I would run it as is, If it really bothers you then just clean it up with some sand paper and it will be good to go. You only need to remove the sharpness of the edge not sand it out all the way.

ChopperDoc

That damage is negligible. Same as above, blend it out with some sand paper and run em. Those are some purdy pistons btw.

brandon6.0

iTrader: (32)

Ill take them off your hand if u dont want them haha

KCS

iTrader: (20)

At a machine shop I used to work for, we would grind that thin area away on all our big power added stuff. They were worried that thin area near the exhaust valve could be trouble, so we would just grind it down and make a nice blended in radius to the valve relief.

tommypenguin

I will likely suggest this when going to the machine shop. That is the thinnest part on the piston which is why I'm concerned about it. Here are pics of the set they are an 11 year old set of lunati pistons. 3.903 bore with -21cc dish. Only .8 gram variance from heaviest to lightest piston.

brandon6.0

iTrader: (32)

Nice pistons for there age.

A.R. Shale Targa

iTrader: (2)

Every single edge visible on the top of those pistons should be cartridge rool addressed and radiused to prevent hot spots/detonation
The dish edges, the valve relief pocket edges and the perimeter where your little mark is....those grooves are called attenuator grooves by Keith Black
Designed to lessen the shear heat insanity that the primary ring sees and if contact is made with the wall it will also minimize the galling or metal transfer