the piston looks bad, but really bothers me is the condition of that rod bearing! that thing is junk. i would assume that all of the rod bearings look the same...
That picture is why I asked for another one. That cylinder looks like a mirror in there, compared to what I can see of the other ones. I'm just wondering if the crosshatch is gone, which it looks like it is. If Bill O. could take a pic with the camera as close to the engine as possible, and then point it at the cylinder wall, it might show us something. My concern is if the cylinders were ever properly honed, or did someone use a really fine honing stone with chrome or cast rings. Also (to Bill O.), can you move the rings at all in the oil groove? They look to have a lot of crud in them.
I would recommend that if you ring and bearing this thing, that you take the rods in and have them checked to see if the bearing bore is round. If the engine is supposed to have low miles since its rebuild, then based on the bearing condition, I would suspect an out of round rod bore.
I took the rings off the cylinder but I could not move the oil ring around at will. Should this ring float freely?
Also, I do not see the cross-hatch pattern that you are speaking of.
See the piston without rings:
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The big question in all of this is do I want to continue to invest in this engine. I found a 79 year 4.2L engine that has just been rebuilt that is selling for 50.00 to 100.00. The problem is I can't contact the rebuilder and confirm the bore or work that was done. The seller bought a package which included the frame, engine, and tranny and he doesn't know alot about jeep engines, mostly chevys. He didn't need the engine and that's why he's selling. He looked inside the valve cover and he said it looks fantastic. Clean like a rebuild. Definately not like a 79 year should. He's suppose to be sending me pics tonight. The problem is it's in Utah which I could go borrow a truck and pick it up then get someone to install it. Also, don't know what's inside.
It's a hugh gamble as I might be buying a 50.00 to 100.00 anchor.
The plan would be to have it delivered to a machine shop/engine rebuilder to have him check it out, put the 4.0L head on it and put it in the jeep.
My Opinion, from looking at all of your picctures and you're description of the removal is that there are multiple problems here. That cyl wall is extremely glazed and no evidence of a crosshatch, which is very unusual given that there's so little wear in the cyl evidenced by the absence of a ridge at the top. It also sounded like the piston came out too easy, no tension left on the rings for some reason. The rod bearing, as you've found out is toast. Definately a contributing factor in the oil situation. Normally I would suspect the engine to have been run hot with these symptoms. The puzzle is why is the #2 cyl so apparently worse than the rest. What does the bearing surface of the crank feel like. Run your finger nail across the journal and feel for grooves or ridges. If it's not near perfectly smooth don't waste anymore time with it, it's a boat anchor. If the crank looks good, pull the rest of the pistons and take a look. Pull a main bearing cap farthest from the oil pump and see what it looks like. If the crank looks good you'll need a micrometer to measure it. If it measures up okay, re-ring all pistons and replace all bearings, main and rods. Steve
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