Che70velle

iTrader: (6)

Looks better than a lot of pistons I’ve removed. The scuffs there are at the largest part of the piston, when measured at room temp. Running temps puts the dome diameter very close to the skirt diameter, making the piston uniform in the cylinder. I’m not the guy on here that tells folks to re-use their parts 99.9% of the time, and anyone here will agree with me there. However I’ve re-used pistons in an 80k mile LY6 and it runs great. It’s a pretty mild build, much like your doing. Click on my Chevelle build link in my sig, and go to post 35. It shows a pic of the scuffed LY6 piston before I cleaned it and a clean pic before install. Pretty much same shape as yours. It was a budget build. What I’m trying to say here is that I’d run those pistons…no problem. Your new shiney piston set will look the same in about 1000 miles, once they wear in. Not a bad idea to re-ring it however while your there.

TableLeg

Thanks alot for your opinion which I value greatly. Based on your comments I think I will reuse the pistons after cleaning but change the rings. My next question therefore is do I get another set of standard rings or something else? Will only the stock rings fit these pistons? If not, is there any benefit to using a different set of rings?
Plus, if i end up having to file the rings to fit where will I find the info to tell me at what size they should be?

TableLeg

I wonder if you also know the answer to this?
Can the stock rod bolts be reused? I don't know if the bolts themselves are Gen III or IV and I can't seem to find a stock GM number for them online (if they need replacing).

pdxmotorhead

There are some pretty competitively priced COATED pistons out there ,,, I don't like pulling engines so I tend to replace a few things..

good luck..

swathdiver

11570662 for Gen IV. They are single use.

https://www.gmpartsgiant.com/parts/g...tra2=&filter=()

TableLeg

Would mine be Gen IV bolts then do you know?
As I understand it the L33 is a bit of an odd ball so far as rods and pistons.

G Atsma

The L33, like most later Gen III LS engines, got the better rods and bolts.

Che70velle

iTrader: (6)

Stock ring sizing is fine for the power level your at. I’d gap top ring at .018 and second ring at .020-.022.

Che70velle

iTrader: (6)

Your rods are gen4 according to your pics. The rod bolts can be re-used. I’ve done this many times. Torque them to 47 ft. Lbs.

TableLeg

That's good to know👍🏻

Many thanks 😊

TableLeg

Thanks for clarifying 👍🏻

TableLeg

Excellent, just the sort of info I need 👍🏻

TableLeg

Any thoughts on the rings? Post#22

Che70velle

iTrader: (6)

The Oem rings are sized for reliability and are fine for the power level your at. As far as a recommendation on brand? Not really. Go to Summit and look around at 1.5 1.5 3.0 ring sets for your 3.78 bore size. Some will be gapless (pre-gapped) and others will require you to file-fit.
edit…shooting from the hip here on the sizing by memory. Double check me there. I’m at work…

TableLeg

Thanks again Che70velle,

I also wondered what your thoughts are on the bearings. I see you used King bearings but when I searched up LS King bearings there's several different ones. I'm only looking for comparable stock ones if they are indeed better than stock ones.

Che70velle

iTrader: (6)

Bearings are definitely one of those choice items. I do like King bearings. The sizing is extremely consistent. The issue at hand here is that simply ordering bearings via Summit will generally net you problems. Sometimes I can pull a standard size bearing out of the drawer, install it, torque the main cap…or rod cap, whichever…and after doing the math, it works perfect. But more often than not, I have to go through several different sizes to find the clearances I’m looking for, which is application specific of course. This is why I keep a lot of bearings in the shop, like a couple grand worth. A lot of times half-shelling is necessary also, meaning I’ll use a half-thou on the upper, and a standard…or even a full-thou…on the lower to find the number. It’s very common practice actually to do. Oddly enough here, I have mostly Clevite bearings in the shop to use for most builds, based solely on a cost standpoint. If I’m getting into a max-effort build, then I will get into coated stuff. I’ve sent bearings out before to be coated for builds. Sometimes I can find a size with King that I can’t get in a Clevite, etc. Lots of variables when setting up bearings. I’m picky and want it right, is my problem. My machinist that I use, stocks $20-$30k in bearings at all times. He’s been a huge asset at times when I need a really odd size…he will usually have it.