2016Husky

So, I’m putting the pistons into my 408 build and I had a silly thought as I was lovingly clocking every piston ring.

Did GM clock piston rings on these engines from the factory? Do you think they even bothered clocking rings in the high end motors (LSA, LS7, LS9)?

I suspect that either GM had a tool that automatically clocked said rings as they were installed on the pistons, or that clocking the rings isn’t actually as necessary as we’ve all been lead to believe and GM just sent it from the factory. (My gut seems to believe the second one)

Does anyone have any first or second hand knowledge of how they were built new?

grinder11

iTrader: (1)

Don't know for sure, but I suspect that you are correct on a production clocking setup....

Che70velle

iTrader: (6)

The engines are built by robots. Serious. Robots don’t clock rings. The handbuilt engines don’t get theirs clocked either. I’ve watched a few videos of friends doing the handbuilt ls7 deal, and there is no special attention given involving clocking the rings. Cylinder crosshatching causes the rings to turn until they seat anyway, so they are never where you set them at when you tear it down. Do I clock mine? Yes. Habit I suppose. I’ve built quite a few race engines with polished cylinders (no crosshatching) and the rings don’t move around at all.

grinder11

iTrader: (1)

We built piston ring machines where Iworked for 40+ years. The macines actually turned the the rings O.D. and I.D., but didnt clock them or install them on the pistons. We did Sealed Power, Perfect Circle, Speed Pro, a bunch of the major ring Mfgrs. They eventually sold that part of the business, and concentrated on transmission leak test machines. Robots probably did at least 70% of the work, and semi-automated special pneumatic tools did most of the rest. One interesting thing I worked on was a "station" that ran down, and tightened the valve body bolts, all of them in one operation. We used Atlas Copco equipment, like strain gauges, to set the proper torque on all the bolts. It was very interesting work, as each spindle, maybe 12-15+, depending on which valve body was being torqued down, had to be calibrated. I truly do miss the work and the guys I worked with....

RonSSNova

iTrader: (3)

You are supposed to line all the gaps up, even the oil ring rail gaps…..right?

grinder11

iTrader: (1)

When I build an engine with the 3 piece oil ring, (can you find a 1 piece oil ring anymore?) I try to clock each scraper 180° apart, iirc. As for the top 2 rings, most manuals I have seen recommend clocking them 120° apart. I'm sure everyone has their own method. Some guys won't install rings on a piston without a ring expander, others won't use an expander, preferring to "walk" the ring on one groove at a time.

RonSSNova

iTrader: (3)

I follow the ring suppliers guidelines.
I pay attention when I assemble, I never look when I take it apart.
I put them on with my thumbs. I don’t walk them on.

grinder11

iTrader: (1)

That's how I do it, too. I've tried ring expanders, and suppose they're OK if you've done a lot of installs with them. For me, it seems too easy to over expand the ring. I do know my thumbs get a bit sore when I get to the last couple of pistons, lol...

Metalchipper

that’s how an old timer show me.
And it works!
I wrap masking tape around the thumbs.