I have a 90 jeep Cherokee 4dr lifted on 31s and I bought a 87 Cherokee 2dr a while back for parts. After pulling the engine from the 2dr and pulling the head (it had a blown head gasket) I found out the cylinders were bored .40 the engine from my 87 was also made by amc but the engine in my 90 was mfg by mopar And it has .50 cyl. I was going to drop the 87 engine into my jeep until I found that the block and head were warped.. My 90 only needed rings so I pulled the rings shaved them just a hair so they would fit in my cyl correctly but after putting them together and putting the cyl back in it feels like there is a drag. I'm hoping it won't be too much when the head is put back on... I'm really tight with money right now and the only way for me to get rings is to order them from the mainland ( I live in Hawaii) any suggestions or ideas on the matter would be appreciated. This is my only vehicle and I have a fam to take care of so I have to make SURE this is going to work before I put it all back together..

 

I never did it on a liquid cooled engine, but did on air cooled motorcycle engines. Using a ring .010" over the piston size and filing the end gaps to proper clearance worked fine. Honing the cylinders to remove the glaze is a good idea if you want them to seal.

 

Well that makes me feel A LOT better cuz I was jus checking this one last time before I put the head on... An yea I honed them pretty good but I think I'm gonna hone one more time to get good crosshatching...

 

I came out of a Hot Rod shop once upon a time. That said Sailboat engines, gas and diesel generators, irrigation pumps driven on propane.....not at all unusual. It will work just fine measure, measure, measure and then measure again. Often times we could not get the "correct" parts. To the catalogs we would go for oversizes, about the right size. After finding something that was close you started filing.

My engine was a 4 bolt main, 327 bored 40 over with a 5 under crank. Block and heads wound up decked so that I had a 10.3 to 1 compression ratio. Put an honest 300 horses to the ground, was smog legal and got 15 mpg.
Ask 99% of the engine builders out there, they will tell you I'm a liar. Ask the 1 that knows, he will smile and say "yep". THAT'S the guy you want to ask for help!

Ron