Just finished a complete rebuild of my 2000 Cherokee Sport 4.0 engine. Had a cracked head, blown head gasket, badly holed #4 piston and scored cylinder wall. Got a TAPY head from a 2003 Grand Cherokee with low miles, a .060 oversize set of pistons and rings, all new standard size bearings and timing set. MLS Victor-Rienz Head gasket and all others were Felpro. Pre-lubed with a cordless drill and adapter. I have rebuilt MANY engines from Studebakers to Cadillac Northstars and many Mazda, Mitsubishi, Isuzu etc. modern V6 and 4-cylinders. This ole' style pushrod inline 6 was like a puttin' on your favorite pair of jeans. Nothing difficult or technically confusing,..just good old low-tech but well-built American engineering. One startling event did have me worried though. It was blowing a ton of smoke for the first 20 minutes upon startup. Virtually every rebuild I have ever done, I got nothing but maybe a minute or two of very light cylinder prelube burnoff smoke and never had piston ring seating issues. For piston-ring seating I did the 2000 rpm for a 2 minutes,..idle 2 minutes,..3000 rpm for 2 minutes,...idle 2 minutes and repeated this process a couple more times. It was still smoking so I then drove the jeep back and forth down a rural road up to 50mph with sharp accelerations. Finally after about 15 minutes of driving the smoke stopped,.WHEW! Runs excellent and smooth. Thanks to this website for the TON of great tips and information provided. Have a great day everyone!

 

I can't wait to build mine, nothing extreme, just a blue printing and a small over bore. I thought of doing the whole stroker thing, but I haven't made up my mind yet.

 

Probably wouldn't hurt to put an oil catch can on that bad boy

 

Got any pics? LOL. When I put mine in I got about five minutes of prelube burnoff then it settled in. Runs great, mines .30 over and was a crate motor so
I could get the warranty with it. Did you put a different cam in or just stock?