Doing a Rebuild?

Long Post Thanks for reading…

I am looking at a really Cheap Jeep (engine gone, still runs and idles good, but has rod Knock)

I am looking at what all I will need and the steps to rebuild the engine. I have a factory service manual for my ‘95 (not to much is different for a 99 is there?) but this is a '99 the body is supper clean with Very little rust only on the fenders and engine is quite clean.

So the items needed... I have a large array of tools (will need a ring expander and ring compressor but those are not expensive). But have all sizes in metric from 5mm to 18mm for wrench, and sockets (all 12 point) deep well and standard. And similar sizes for standard along with larger items needed for stuff like Tie rod work, ball joints, and axle shaft removal. I have a ½” torque wrench (about an 18” long arm). And lost of pliers, screwdrivers, Torque sockets, feeler gauge kit, and Alan wrenches (both standard and metric).

Are there special tools that I will need that I may not have? If so what? A set of calipers will be a good idea I am guessing…?

I am looking at the following Master Rebuild kit ( ROCK PRODUCTS Part # EK1123M from Rock Auto.) It has Full Gasket Set, Piston Rings, Pistons, Freeze Plugs, Main and Rod Bearings, Oil Pump, and Timing Kit/Belt.

With Rod Knock should I look at getting a new crank off the bat or see if a shop can balance the one I pull?

What other things should I look at getting for the rebuild? With having Rod Knock does that mean I should automatically assume a new crank shaft?

I will need to take the bock to a shop and have it de-glazed/honed for the new pistons. Is there anything else I should have them do (don’t have the funds to do a stroker....)

So have a shop Hone the block's cylinders, test for cracks?, Balance Crank shaft?

The rebuild should be fairly strait forward.
Drain fluids, un-mount transmission, remove electrical connections, remove engine mounts and pull engine. Start removing parts until all removed, clean engine, replace parts that need replacing and build in reverse order making sure I use right shims and tolerances on all parts. Once everything is done will I need to re-brake in the engine (using brake in oil and using the RPM’s for certain lengths of times... with cool down cycles?) or will that only need to be done if I do work on the cam shaft?

did you determine the engine has rod knocking or is that what the seller said? I ask because I have had 3 of many 4.0 develop "piston slap" which sometimes confuses an amateur into thinking it's "rod knock". I drove 100,000 miles on a motor with a slapping piston. you may not need to rebuild, unless you just want to

Well it has been identified (so the seller says) to have rod knock by a few mechanics. I have not asked where she took it as when I went to look at it, it was not even able to start (bad battery and the seller had really crapy jumper cables.)

How do you determine between rod knock and piston slap? I have been informed that if I pull the plug on each cylinder one at a time and I find one that the knock goes away or lessons thats the cylinder with it. Any further pre-diagonosis with out having to take the egnine apart would be helpfull but dont think there are to many other ways.

Edit: after reading more on Piston Slap I feel like it would not be piston slap. The knock only comes when its warm. and my light reading said its most likely to be more evident at first start up or cold. I guess a pressure test would be a good test to do on it to see if a cylinder has lower pressure which it seams piston slap would allow...

DON'T.

You are getting over your head and going to find out that all the other labor you have to pay for is going to run the price WAY up.

Pick up a low-mileage used 4.0 and swap it in.

Just determined that out... and actually looking at something like this...

http://www.rebuiltautoengines.com/jeep-L6_4_242-amc_242lb_4-engine.html

http://www.rebuilt-jeep-engines.com/

http://www.quadratec.com/Showcases/jeep_replacement_engines/

http://www.hiperformer.com/engines/jeep-cherokee-rebuilt_engines-amc_242lb_4.html

http://market.autopartsfair.com/jeep-car_engines/cherokee-1999-rebuilt_engines-amc_242lb_4.html

Any of these I should avoide or go with?

These are already built, and come with a warranty (more so then a used 4.0 from a JY) I know someone close by that has a motor out of a 2000 (1999 to 2001 are all inerchage able right? no new computer needed?)

If I do this I might keep the other engine and take a hit on the core charge and do a stroker build for my '95. a long term build.

You should post up for opinions on a few more Jeep forums so you end up with a wide view on those builders.

EDIT: a cursory review of those engine build sites and two I noticed list the "331" head--if those are original 0331 head castings then avoid those engines like they had the plague.

Aww those are the ones that always crack right? So if they are a revision or a recast but still are marked 331 are they good?

And or to add to the list if any one knows of a builder that sells blocks that are trust worthy would be a help.

Thanks!

being a jeep technician heres what i would do. go talk to your local TRUSTED machine shop. they are the best way to go. you dont have to pay truck freight shipping or core charges. you send it to them as a long block and they give it back to you as a complete rebuilt long block. they also will be able to warranty it faster if it blows up compared to one of the catalog companies. the last 4.0 litre bill i saw from the machine shop was around 1000 dollars. and you should always break in an engine but you dont have to do the cam break in (hold it at 2000 rpm right when it starts for 30 min) unless the cam is replaced.