To Ring or Not to Ring

Discussion topics on Willys Overland M series vehicles
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Silverback2w2
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To Ring or Not to Ring

Post by Silverback2w2 »

My 1955 M38A1 sat in a dry dry new mexico back yard for 27 years. I'm bring her back to life and I'm going through the engine to inspect and replace all the seals and gaskets. The clock says 55K miles. The engine looks great inside so far.

I have the crank out of the case, should I go ahead and re-ring the pistons?

The cylinder walls look ok and there was not a whole lot of carbon in the combustion chambers.
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wesk
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Post by wesk »

Eyeballing is not the best way to determine if you need rings.

An inside dial indicator or bore taper mic is what you need. Borrow one or haul the block and the four pistons with rings to your local engine machine shop and have them mic the bores, the pistons, and gap check the rings in the bores and gauge the piston ring land wear. Only then can you make a valid determination on what is needed.

Are you also eyeballing rod and main bearing needs?
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
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53a1
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Post by 53a1 »

Had a similar situation with an engine I bought for cheap. Seller said it was rebuilt by his dad 20 years ago.

Took it appart anyway and had a VERY GOOD machine shop measure and advise. Found it was 90% done right but the rings were too tight and valves seats were ground wrong. Had the machine shop hone, grind valves and pressure clean. They ordered all the parts for me and helped offered help as I put it back together myself for fun.

So lesson here is I spent 200 total and have a solid RUNNING engine but I could have been lazy and ended up with a frozen engine and who knows what other problems.
'53 M38A1 X2
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BullRun
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Post by BullRun »

In my own experience I have found the F-Head M38A1 engine to be a nearly unbeatable engine for durability... with a unique characteristic of still being able to run long after a rebuild would be advisable.
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