Advice: Engine replacement or rebuild?

[WhiteKnight2]

Well i guess its time to do some much needed engine work. I have been wheeling the Sh!t outta Optimus (my 95' xj) but it seems like he's finally tired of the abuse. Its been over heating religiously and i have oil in the radiator and coolant in the oil pan. I figure i have a blown head gasket possibly a cracked head and maybe, but lets hope not, a cracked block. I recently purchased a 98' xj as a parts jeep for $800, a great investment in my opinion due to the fact that it has a good running engine 5 speed which i dont need (if anyone does its 4 sale) axles are good body is good except floorboards, same color interior as mine and the glass is all good. So now to the nitty of the gritty. Do i replace the engine in Optimus with the 98' or just rebuild and use what parts i need? I would like to get it together as soon as possible because i love to wheel in the snow and its here. Im not sure how easy the swap is because the pulleys on the front are diffrent which leads me to believe their are more diffrences, and i have no idea what else i will need. I also dont know what kind of abuse the other engine has been through and if i tear it down to check i might as well just rebuild the one in Optimus.
Advice on this would be helpful. If i can just swap engines quick and easy i will, that will give me time to really work on the other engine (4.7 stroker if i have time). :D

What do you guys think? Swap or Rebuild?

Also in the works are both front wheel bearings, axle joints, and a lock right locker for the rear.

[Mudderoy]

Well i guess its time to do some much needed engine work. I have been wheeling the Sh!t outta Optimus (my 95' xj) but it seems like he's finally tired of the abuse. Its been over heating religiously and i have oil in the radiator and coolant in the oil pan. I figure i have a blown head gasket possibly a cracked head and maybe, but lets hope not, a cracked block. I recently purchased a 98' xj as a parts jeep for $800, a great investment in my opinion due to the fact that it has a good running engine 5 speed which i dont need (if anyone does its 4 sale) axles are good body is good except floorboards, same color interior as mine and the glass is all good. So now to the nitty of the gritty. Do i replace the engine in Optimus with the 98' or just rebuild and use what parts i need? I would like to get it together as soon as possible because i love to wheel in the snow and its here. Im not sure how easy the swap is because the pulleys on the front are diffrent which leads me to believe their are more diffrences, and i have no idea what else i will need. I also dont know what kind of abuse the other engine has been through and if i tear it down to check i might as well just rebuild the one in Optimus.
Advice on this would be helpful. If i can just swap engines quick and easy i will, that will give me time to really work on the other engine (4.7 stroker if i have time). :D

What do you guys think? Swap or Rebuild?

Also in the works are both front wheel bearings, axle joints, and a lock right locker for the rear.

I just had my AW4 rebuilt in my 98, so I thought it might be a good time to rebuild my engine. I didn't want it down for weeks while I did it, so I called a local shop for prices and time frame. They used to do strokers, but they 4.2 cranks have got really hard to find, but they offer a 250 - 270 HP 4.0 HO. Plus he said it was a PITA working with the ECM where the higher horse power 4.0 didn't have this issue. I mean stroker sounds cool, but what I wanted was more horsepower and torque.

They said it would take about 3 weeks. 2 to build the engine and 1 to swap it out/in my Jeep. So I'm looking at a month anyway. I'm checking in to how I get 250 hp out of a 4.0.

[4.3LXJ]

To me the quickest thing would be to take the head off the 98 and send it in to be rebuilt and put it on the 95. Solves any dilemmas about cracks and such. Then you can work on a short block at your leisure. That way you only have a day of work in it and reap the benefits of a new head you can use later.

[LizardRunner]

Gotta agree with steve on the best, fastest cheepest way to go on this one. btw, how much for the 5 speed? mine seems to have a bent fork.

[denverd1]

Not sure how tough these blocks are compared to others, but I'd bet its the head gasket and not the block. Although if its overheating regularly you may have warped something, but not likely. swap those heads out get out in the snow! good luck with it.

[Cheromaniac]

Well i guess its time to do some much needed engine work. I have been wheeling the Sh!t outta Optimus (my 95' xj) but it seems like he's finally tired of the abuse. Its been over heating religiously and i have oil in the radiator and coolant in the oil pan. I figure i have a blown head gasket possibly a cracked head and maybe, but lets hope not, a cracked block. I recently purchased a 98' xj as a parts jeep for $800, a great investment in my opinion due to the fact that it has a good running engine

So now to the nitty of the gritty. Do i replace the engine in Optimus with the 98' or just rebuild and use what parts i need? I would like to get it together as soon as possible because i love to wheel in the snow and its here.

I suggest you pull out the 4.0 long block from the '98 (minus the '98 accessories) and swap it into your '95 XJ so that you have a good running engine for your daily needs. Then you can tear down and rebuild your old '95 engine into a 4.6L stroker at your leisure.

[bluedragon436]

^^ I would do this too if it were me!!... And he knows what he's talking about with the 4.6L build..

[BlueXJ]

A 4.6L stroker woulg get you the HP and Torque that you seek and I would go find a low mileage JY motor and build it so that you have a 1-2 day downtime while you do the swap.

[Cheromaniac]

A 4.6L stroker woulg get you the HP and Torque that you seek and I would go find a low mileage JY motor and build it so that you have a 1-2 day downtime while you do the swap.

He already has two engines so he just needs to rebuild one of them. Once it's finished it's just a weekend's work to remove the old engine and swap the new one in. It's also a good opportunity to detail the engine bay, replace old/broken rubber/plastic hoses, and tidy up the wiring.

[saar]

I would put the 98 one in the 95.
(verify it fits before)
if it is "bolt on" I wouldn't start messing with the old one, maybe just for fun :)
Saar