What does this mean?
 

LQ9 used factory pistons were brought to a machinist and he said Measured from the pin to the tip of the skirt of the piston the measurements vary from .003 to .005 to .007 off.

I am not sure what this is, but can someone school me on what this would do and how this affects a motor? I understand that if this was WAY off but the length of the skirt being that little off?

Thanks

The skirt just keeps the piston for rocking inside the bore. I wouldn't be concerned with that small amount of variance, especially on a stock piece. :) Now if he had said that those variances were from the crown or top of the piston, then I would be a little concerned. As that measurement would affect the deck height of the piston (piston to head clearance, and compression ratio measurements).

its kinda hard to understand if your not a machinist or not familiar with numbers like that but il put it this way .010 is the thickness of a piece of a notebook paper!! i wouldnt worry about it.

A piece of notebook paper is about .004". Maybe Two sheets. :)

GM's piston slap


what are you building? If you're boring it out, you can't use the factory pistons

My LQ9 6.0 is ready to go.... This is to do with a used set of LQ9 pistons I sold

I do not want any issues with the person buying them, but they are used, and I see no reason why they can't be used again.

they're good for a stock bore, and new rings

I don't think the piston being a few thousandths shorter would make piston slap. If it got more narrow at the bottom of the skirt I would say it might cause piston slap.

These are the updated 03+ pistons with the coating on the skirts to prevent piston slap

never mind, they'll work