McRay

Will 1998 4.0 swap out with 2001 4.0
is the brackets on the head and block the same. Ignition, distributor is different will need swapped over. Does anyone know other problem I will run to.

5-90

The 2001 head (0331) will have the bosses drilled and tapped for mounting the coil rail - the 0630 (1998) will not. I believe accessory mounting holes are the same, but I've not yet had a chance to check.

The 1999-up intake is different, so you will likely have different accessory mounting (at least, with the power steering pump.) You can put the earlier manifolds on the later head, and the heads can swap back and forth on short blocks as well.

I take it you don't have the engines next to each other to compare?

McRay

Have bought 2001 jeep Cherokee Sport motor has bad engine knock. Have not removed engine from vehicle- found 1998 motor with low miles from a jeep Cherokee that been hit in rear for $450 motor looks that it is in good shape. Also thinking of putting a crank kit in if when engine is torn down that not to much damage to lower in.

I have 1996 jeep Cherokee by looking at the 2 engine side by side that ignition and the distributor, intake are different. But who knows what problems that you can run to.

5-90

Make it easy on yourself - just swap out the short block! If it's a bottom-end knock, there shouldn't be anything wrong with the head, and you'll just need to move the cam sync/oil pump drive over to the replacement short block in place of the distributor. Easy!

JeepCoMJ

ditch the 2001 head. they are prone to cracking and CAUSING top and bottom end issues.


everything else will bolt up...use all the 2001 engine's sensors, intake, and exhaust manifolds. you will need to make adapted brackets to mount the coil packs on...but no biggy. you will have a superior head and such.

5-90

Exactly what I was saying - swap out the short block (assembled engine block less cylinder head assembly) and you're good.

And, if you're anywhere near San Jose, CA, let me know. I need a 0331 head for analysis (it's not going on an engine, but it's eventually going to go through a bandsaw...)

JeepCoMJ

I have an 01 head...0331 I believe. it's bad.

-Pat

5-90

2001 used the 0331 head - all models.

Easiest replacement is to get an 0331 replacement from a 2002-up WJ/WK/TJ, as it's a direct swap and ChryCo revised the casting to fix whatever was causing the problem.

If we can sort it out, I still want a couple of 0331 heads to section and analyse - partly to figure out what was wrong, and partly to figure out a few other things (like an true "apples to apples" head flow comparo, for instance.)

JeepCoMJ

yeah I just posted that cause I figured you want it. I'm absolutely not interested on rebuilding the motor with an 0331 head. I'll be putting a head off of a 95 on the motor but with 2001 intake modified to fit the borla header.

-Pat

5-90

Where are ya?

JeepCoMJ

SE wisconsin...

I won't be home/able to get the head for a few weeks...out in PA for my main job right now and then I have to get the public pool set up for this summer's season and get my new staff trained

pm for more details

-Pat