The Stovebolt Site Forums The Shop Area Engine Shop 235 Piston Rings

I recently acquired a used Chev 235 truck engine. It came with transmission, clutch, generator, starter and manifolds with carburetor, but all the 'accessories' were removed and in boxes. I was told it ran well when pulled. It's been sitting around for several years in a dry barn. At least all the openings were well sealed up and nothing was seized.

It took a while to get it assembled enough for a test run. It ran OK without any major internal engine noise. A compression test showed one cylinder had 75PSI, but the others were in the 135 range. Off came the head to identify a burnt exhaust valve in cylinder 1. The rest of the exhaust valves need a re-grind. The intakes looked perfect.

We pulled the oil pan off for a quick check. Bearings looked perfect. Maybe 0.040 undersize on the mains.

Then the surprises kept coming. Oil pump tube fittings were finger tight. Flywheel bolts were not tight. Camshaft gear was not pressed in tight and there was 1/8" endplay.
Pistons were 0.040" oversize. Some have some mild surface erosion due to pre-ignition? But the rings seemed to have about 0.050" end gap. We're guessing it has 0.030" oversize rings in a 0.040" oversize bore ?

So, it needs new rings and a valve job.

Lately it seems that parts are getting harder to find.

Any suggestions on brands or quality of Piston Rings and Valve seats and guides?

John.

Egge Machine

Never heard of Egge Machine - what is that ?

One of the largest engine parts retailers in the US. Google them.

Egge uses the Jesse James business model. The only difference is that Jesse had to use a gun to rob people. On any particular day on Ebay, I can buy a truckload of new 235 parts, at very reasonable, or downright cheap prices. That goes for pistons, rings, bearings, gaskets, valves, and even crankshafts, cams, and connecting rods. The resto-ripoff places like to claim that stovebolt stuff is scarce and gold plated- - - - -not so by a long shot! If you're not willing to do a little internet shopping, there's always Rock Auto- - - -good brand name parts at fairly reasonable prices! Now, for scarce, custom made stuff like GMC pistons, you might have to bite the bullet and pay Egge's prices, but not so for regular stovebolt rebuilding parts!

What's wrong with a .050" ring end gap? When the rings heat up to normal operating temperature and expand, the gap will be virtually zero, and at 2K RPM they're only having to seal compression and combustion pressure for 1/60 of a second at a time. Measure the pistons and/or the bore size with an accurate inside micrometer, and order the proper size rings to fit.
Jerry

Rock Auto. Nice new pistons rings, Sealed Power, $45.00

https://www.rockauto.com/en/catalog/chevrolet,1957,bel+air,3.8l+235cid+l6,1326147,engine,piston+ring,5640

I am with Jerry on this. I ordered a set of GMC 302 rod bearings from Egge a while back because they said they had them in stock. The bearings arrived and had been coated in a like black graphite coating. When I looked at the bearings closely, they were all the same size but from three different manufacturers and the bearings that came from similar manufacturers were from different lots. It was a put together set. I did not pay a premium for a put together set. I then proceded to wipe the bearings with lacquer thinner and low and behold, these were some messed up bearings with nicks, gouges, and corrosion that had been dressed with scotch brite and coated. What horse pucky. Worse, they would not take them back and refund my money. Never again.

Second ebay or Rock Auto. If must use a specialty supplier go with Terrill Machine out of DeLeon, Texas. as they just rob you rather than rob AND rape you like EGGE.

Hahaha! True.