Originally Posted by iregret

From Hot Rod:
Our guinea pig was a 5.3L truck motor, while the punishers were a pair of 76mm turbos from CXRacing plumbed into a homemade twin-turbo system. When we got it, the engine was a grimy core from a junkyard. We took it apart and found a pretty significant rust spot in the No. 8 bore that a ball hone wouldn't remove, but it was halfway down the bore so we thought, What the hell, we're trying to kill this thing anyway. It won't matter. The motor was reassembled using the original crank, rods, flat-top pistons, rings (a little rusty but they cleaned up OK), and bearings.
****The sole modification to the short-block (at the advice of Jerry Stetler from Ace Machine) was to increase the gap of the top rings from 0.015 inch to 0.028-0.030 inch (we reused the original rings). The second (factory gapped at 0.028 inch) and oil rings were left untouched.****

Stock GM LS Engine - Big Bang Theory - Hot Rod Magazine

Originally Posted by AKlowriderZ71

I'm trying to find out what works, and what doesn't. It's an L33, 9.95:1 CR, 799 heads, trucker cam, MP112 at 10-11 psi, likely to see 14-15 psi eventually. There's also a possibility of some nitrous later on, but probably with 10-11 psi.

Anyways, for stock pistons, and stock rings, on a stock bore diameter, what's a good ring gap? Mine are currently at .020", and here's the aftermath.

On a good note, everything else is in great shape!

Originally Posted by Jablowme

1 new piston is gona be a bandaid fix and not for long as the rest of your pistons have alot of detonation pits on them

Originally Posted by DeathByNissan55

Waking from 3 year slumber, but the fact that they used the flat top pistons as opposed to the dished won't affect that preferred ring gap for turbo 5.3L application?

One thing people didn't mention (at least I didnt see it) is ring thickness and how much of the ring land that top ring filled, this could be an issue too due to expansion when heated. If ring was too thick and ring land got narrower, that could cause it to break the top of upper ring land, right?

Originally Posted by DeathByNissan55

Also, I thought different material piston rings altogether along with some extreme ring gaps is recommended for nitrous.
I dont think there is an end all product thats good for all setups, its either you build for nitrous plus other mods or just the other mods.

Input would be appreciated.

Originally Posted by AKlowriderZ71

Back from the dead!!

My band aid fix made a bunch of 11.6 passes at 14 psi, tons of daily driving street abuse, and then I swapped it into my wife's Yukon. She drives it every day.

Originally Posted by AKlowriderZ71

I'm not sure what your question is?