Shot a piston out the side of my block last spring and finally am finding the motivation to buy a core engine block and rebuilding it. Its a 2000 and since I also bent some pushrods and collapsed a rocker arm I'm also looking into rebuilding the head. I started researching rebuild kits but they seem to usually carry pretty ****ty parts and nothing really for rebuilding a head, I am also wanting to put head studs, a high end gasket kit and a slightly bigger cam in it.
Summit sells mostly mopar replacement parts which are way too expensive for what they are, where are you guys buying engine rebuild parts? anyone have a good spec sheet where I can find parts that are interchangeable?
Thanks

 

In for results, just bought a second XJ with a ton of parts on it but the engine is blown ( haven't pulled it yet but it's pissing coolant everywhere and there's a knock when I turn it over, I knew about the engine got it for cheap considering what's on it ).

I also felt the rebuild kits out there left a lot to be desired. So many differing opinions on reman engines from my research. Still trying to find a shop locally to see what they'd charge to build a 4.0 since I don't have the tools to do it myself.

 

Falcon Global on eBay is the best I've used.

 

For my Comanche I took the block and head to the machine shop and had them bore, clean, check the flatness and do a valve job and all that. Swapped in LS valve springs, comp cam and went through them to source a rebuild kit. Just used felpro gaskets and new head bolts.

For my Cherokee I took the block and head to the machine shop and had them check it and all that. New valve springs, but just stock rate. Went with a cleggs engine stroker kit and a stage 1 cam from them. Used felpro gaskets and stuck an mls headgasket from the later model 4.0s in with new head bolts.

 

Yeah, take the head and replacement block to the machine shop. Defintely get re-done.

I would encourage you to look at short or long blocks assembled. Rebuilding an engine takes a lot of work. Seems to be 3x more than when yer looking at it from the front end -- I've rebuilt several. There are a lot of replacement engines out there fairly inexpensive nowadays. Even if you end up rebuilding yourself, why not price some out. It'll put you back on the road faster.

But, hey, I get it, it's also very fun and rewarding to rebuild an engine.

 

I've always had a second vehicle to drive when rebuilding an engine so I haven't really worried too much about build time. The stroker I got back on a Wednesday put it together and then had it running and drove to the car wash thursday night. The time is in the machine shop really. Everything else is just popping it all together.

 

I have also rebuilt several and honestly I am at the point where I only trust my own work on something like an engine rebuild especially when I am trusting this rig to bring me home from deep in the wilderness. I also have a dd and a backup truck and a gambler so build time is unimportant and I will be spending a few months working on this one. Getting the head surfaced along with the new block decked, bored and everything inspected is on the list along with grinding the valves, balancing the rotating assembly (so I don't have to use a harmonic balancer) and port matching the head. I am looking into installing a bigger cam but probably wont because I don't want to run into vacuum issues, Jeeps already leak and throwing a big *** cam in one is just asking for problems.
the main point of the build it to gain reliability since I have never had any issues with power over the years I have been messing with Jeeps. If I wanted to gain power I would do a conversion to a 351W or something similar.
If the head does have a serious problem I would switch to an older style head with a distributor instead of coil packs, will an older computer plug directly into my 2000? Do I have to run a different computer if I switched heads?

 

Yes and no. Putting an engine together "right" isn't always matter of popping it all together if ya want it to last a long time. But I get your point. I'd probably do the same thing. Sounds like you're on top of things. For a lot of guys who don't do it as much or don't have the tools/patience, they might be better off farming out the detaily stuff to a builder.

 

Checking the tolerances and such takes a little bit of time, but after that it's just assembly lube and a torque wrench.

 

I agree. After the rings are cut and put on the pistons and all the clearances are checked, I can throw a 4.0L together in less than 2 hours. But it takes me 4 hours to do all the prep work....

To the OP - get a Tupy or Clearwater head. Dont mess with trying to throw on an older head as it's more work, time and money then it's worth. As for the cam, throw one in! Just dont go with the biggest one you can find. Satiricalhen has a nice one in his MJ. I'm sure he has the part number somewhere and more info on the modifications needed to fit different valve springs.