cav101

iTrader: (10)

Doing a rebuild on an L76 for my 02 firebird. Stock rods, pistons, crank, with some ARP hardware. The car does a Procharger on it. I cannot figure out which rings would be best for this motor, given its not a race car, and does get driven fairly regularly during the summer. The goal is only 700hp'ish.

Che70velle

iTrader: (6)

Are you doing a .005 hone for ring seal, or just throwing it back together with same pistons?

cav101

iTrader: (10)

Light hone to get a cross hatch, stock pistons and new rings was the plan.

Che70velle

iTrader: (6)

If your not interested in a file to fit set, just go back with a GM set or even a Sealed Power replacement set.

cav101

iTrader: (10)

I’m having a hard time determining which is the correct set. Do they have a 2.5mm or 3mm oil ring? Any particular material better then the other? I have no issue with a file to fit set, just want to do it right.

Che70velle

iTrader: (6)

2.5 mm oil ring. Here’s a link to help you decide....

https://www.enginelabs.com/engine-te...d-environment/

cav101

iTrader: (10)

Awesome, so they must use the smaller top ring as well?

Che70velle

iTrader: (6)

Well...you’ll have to measure. There were some differences depending on year (?) and supplier. I’ve read some had 1.5-1.5-2.5. I’ve also read some had 1.2-1.5-2.5. And also some had 1.5-1.5-3.0. If your sticking with Oem slugs, you’ll have to measure your old rings with a caliper. You can do a search and find ooodles of confusing threads on this very subject here on Tech, as well as other forums. Lots of folks just say fooey and toss the old ones for new pistons, just for this very reason.
Personally, my 6 liter builds have had 2.5mm oil rings when I tore them down.

cav101

iTrader: (10)

unfortunately they were tossed during tear down....lesson learned.

88bruce

Post a side view of the ring lands. Using the 2nd land as reference, 1.2mm is a 20% reduction from 1.5mm,
and 3.0mm is a 100% increase. These differences should be detectable by eye.

cav101

iTrader: (10)

Im not sure why I didn't think of this on my own. 1.2mm top, 1.5mm second and 2.5mm oil ring. Thanks for all the help.