So this is an interesting motor to say the least. We got it all torn down tonight and I'm trying to get stuff cleaned up. While it's been suggested that this motor was previously rebuilt I can squash that now. The crank and rod bearings as well as the pistons are original. The bearings have AMC stamped in them. It's also evident that there are some miles on the bottom end. The buildup on the pistons are pretty good examples of that. The oil rings, however, need replacing.
So here's where I get confused. How can the bottom end be so "used" yet the intake valley be so clean? Head gasket job maybe? Ok, so how is it that the block looks like it was cleaned and all the coolant passages are super clean and the freeze plugs look fairly new-ish? And why is there no paint on the block?
Weird.
So what did I discover so far. The crank and rod bearings look good. Cool.
The cam bearings however... Not so much.
Thankfully the instructor for the performance class is in the same building and is happy to help me change them out.
We pulled some measurements on the cylinder bores for taper but I haven't had a chance to look the results up and compare it to specs. Here's the numbers if you can read them and have any idea?
I also took a couple pics of one cylinder bore. It's not as nice as I'd hope but maybe it can be honed and work ok??
Last thing I got for tonight is the timing set. I can only guess it's the original since it's so sloppy. But I took pics so I can compare it with an aftermarket option. I don't see any wear on the gears so I'm wondering if I can get by with just a chain? Anyone have a recommendation for that or a reason not to?
I plan to go in tomorrow very early. I'm going to hit the morning class about half way through when they should be out in the shop. Hopefully I can get left alone and get to scrubbing the nasty off the parts and start some stuff going through the big dishwasher machine. More to come...