A few odd things I found on my new to f134

I bought a used F134 and have found a few odd things...
Leak down showed 10, 28, 24, 28%.

2 and 4 were leaking past the exhaust valves . Excessive play in the crank.
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We have 3 identical pistons and 1 a little different. 3 had what looked like castle nuts and 1 had the traditional and lock nuts. The 3 looked like they had a 3rd compression ring but thinner. What is the 3rd groove for? Are they aftermarket? Can we get rings with a 3rd compression ring?

The crank had a drive yoke on it rather than a traditional nut. Has anyone seen this or know how to remove? The pulley is moving independently.

I can see the crank walk back and forth. Bearings seem fine. I will mic the crank, pistons, bores and bearings.Where do I get the shims and a thrust washer?

I found a ~1"L x 1/4"H x 1/2" tall piece of machined metal. 5 sides are flat and the final long face is curved. Anyone know where this would have come from?

thanks

rich

 

Drive yoke? Do you mean for a PTO shaft?
Some front mount winches, pumps etc ran off the crank. But I imagine in use it would be solidly connected to the pulley/pulley nut.

Jeep pistons have one open groove, the top one, without a ring - as a heat barrier.

 

The #4 piston does not have the top narrow groove and is the oddball. It also has ~1.25" diameter at the center of the piston maybe .010 dished lower than the rest of the piston top. What else used these style pistons? I wonder if the PO replaced only the 4th? #1 measured 1.54 with a digital veneer caliper. I know it is not the most exact but it was what was handy.

The yoke was the nut. I was able to use a pipe wrench to remove it and get the pulley off. It has ~1/8" groove from the key rocking back and forth. I will check my parts engine and hope it is good.

 

Was the PO named Bubba?

 

Drive yoke like for using a hand crank like you see on Model T Fords?

 

I had to make my own set of thrust washers out of shim stock that go on the crank behind the front pulley.

post up some pics.

 

A friend of mine who runs a restoration shop and works on a lot of cars from the 60s and 70s tells stories about the old days when he worked for (dealership service) when factory representatives would head out to dealers to fix vehicles under warranty. Applicable problems were fixed by milling just the one cylinder wall and replacing the one piston. When these cars come in now for out of the garage or barn restorations he finds what you found. Blocks with one oddball piston. Could be your story?

 

You don't need matched pistons for the engine to run... You can imagine somebody had to repair this engine on a really short budget, and took one used piston to repair the single bad cylinder. Fitting a single used piston to fix an engine is not unheard of.

A proper fix would require measuring all the bores and fitting 4 identical (new) pistons and rings, with matching rods. Pistons are the most expensive part of a rebuild, typically. I would not consider trying to put new rings on mismatched pistons.

 

Timgr, guilty as charged. Put one piston, rod and cylinder out of a 1200 cc VW engine we used for parts, into a 1300 cc just to sell it. Was worried about balance, but didn't seem to matter.

 

Don't feel too bad.

I heard about a guy who bought a used car, and after a short while it began to burn a lot of oil. It had one piston made of wood.