[Morts]

Need to replace rings on 3 cyl. Received pt.12499107 (0.005" O/S) ring set. New rings have almost twice the end gap of the old ones. New top ring .033,old top ring.017. Need to know what gives, any help would be appreciated.

[Nothing's Easy]

Not trying to be insulting but you're measuring the gap with the ring in the bore?

[Morts]

Nothings Easy

How am I suppose to measure it?

[techinspector1]

Morts, this is very confusing. Please start at zero and explain in detail. If the old rings were gapped at 0.017", why did you feel they needed replacement?

[Morts]

I didn't give you the whole story. The engine is new, we dynoed it.

Somewhere along the line it ingested a hard object which beat things up pretty good. Three intake valves, two exhaust and one piston. That's why I needed new rings.

I don't understand why the piston they sent is the proper dimensions, but the ring sets are to match are undersized. Part number says they are .005 over same as replacement piston, but when measured in the block, they have way to much end gap. I was wondering if there was more than one design or G.M. has made a mistake.

I really didn't want to tell you why. It hurts bad enough just thinking about it.

Thanks

P.S Ring gap was .o17 from factory.

[cobalt327]

The end gap is measured with the ring installed into the bore, squared to the deck- not as it appears outside of the bore- just so we're on the same page here.

Assuming you've measured the end gap inside the cylinder that is to receive it, it sounds as though the ring(s) sent to you are not necessarily the ring size that's printed on the packaging. I.e. wrong ring, right package.

I'd not install it, obviously. Send it back and get the correct ring for the engine.

You haven't said, but this rebuild is going to require honing the cylinder to match the piston. A 0.005" OS piston will not work in an unhoned std. bore- obviously.

And try not to beat yourself up too bad over the mishap- **** happens. It's what you do to recover that counts.

Good luck.

[Nothing's Easy]

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