Engine swap worth it?

[Swampy]

Hey people,

As some of you way know of my build thread "Wendy". Well I have a 1988 Comanche with a 2.5l inline 4 (tbi) and a 1988 Cherokee with a renix 4.0l/aw4/np242 drivetrain. I tried to start the Cherokee but it was just cranking (not turning over) sounded like it had a rod knock and some smoke was coming out of the dipstick 

 

https://www.youtube.com/watch?v=keTuB2oHwsY    (wasn't sure how to make the video thumbnail appear)

 

But I'm not 100% sure what it is. It sounds like knocking. Because of this, ​ was ​going to keep the 2.5l in the Comanche, and just make the best of it. 

My real question is, would I be able to "fix" the 4.0l for around or less than $700? Because if it is more than that I might as well swap in an ax5 behind the 2.5 and just save for the time being

[mnkyboy]

4.0ls are pocket change,you could pick up a good one for cheap.

 

Or be different and build the 2.5l.

[omega_rugal]

yep that 4.0 is damaged, you can get a good one cheap... but keep that one it begs for a rebuilt

[Jeep Driver]

Allow me to open your can of worms.

 

I don't want to be accused of giving bad advice, everyone has to take their own path. 

 

You asked me about my 2.5, I would not encourage you to do what I did, you'll be disappointed. 

 

Knowing what I know now, I would never do a 4.0 swap. Too much work, time, effort, money for the return. 

 

And no, I promise you you will not fix nor rebuild your current 4.0 for anywhere near $700. Machine work alone will chew that up. 

 

You've already stated that you don't have the tools.....and I'm assuming space.......

 

I would encourage you to rethink what you want to accomplish and come up with a plan.

[Swampy]

Thanks for the info guys. I wanted a second opinion about the motor, if it would have been a cheap I probably would have considered the swap. The plan is to keep the 2.5 I going to stay 4cly. May try to find the parts to swap to mpi.

 

But parts for sure getting

An intertia ring

Regearing the axles

Probably getting a cam and boring the 2.5

And new wires, distributor etc

[Pete M]

to add to your upgrade musings, I recently found out that the Liberty rear axle can be found as an 8.25 with disks and is a couple inches wider than stock.  (the 35 was also available).  I always thought they were the same width as an XJ, but I measured my '06 Libby.  neat :D

 

don't forget to swap out your mech fan for an electrical.  :thumbsup:

[Swampy]

to add to your upgrade musings, I recently found out that the Liberty rear axle can be found as an 8.25 with disks and is a couple inches wider than stock.  (the 35 was also available).  I always thought they were the same width as an XJ, but I measured my '06 Libby.  neat :D

 

don't forget to swap out your mech fan for an electrical.  :thumbsup:

 

Oh that's awesome any year liberty? or a specific range?

 

And yes an electric fan is definitely going to be a nice upgrade as well

[Swampy]

Does anyone know anything about stroker kits for the 2.5l? I have done some research and this company called 505 performance

[Pete M]

mine is an 06.  I'd imagine they are all the same width.  car-part.com can help you find one in a junkyard.  

[HOrnbrod]

Does anyone know anything about stroker kits for the 2.5l? I have done some research and this company called 505 performance

 

  I don't think stroking a 2.5 would do much good. You would get more bang for the buck with a supercharger. Check out mnkyboy's build thread if you haven't already. He's done some nice work with his. 

 

http://comancheclub.com/topic/16226-mnkyboys-89-comanche-project/page-28

[Pete M]

gears are your best bang for your buck.  choose them wisely :D

[HOrnbrod]

:agree:  Gearing is very important too, but I was referring to engine performance mods.

[Pete M]

gears + boost =   :banana:

[Swampy]

 

Does anyone know anything about stroker kits for the 2.5l? I have done some research and this company called 505 performance

 

  I don't think stroking a 2.5 would do much good. You would get more bang for the buck with a supercharger. Check out mnkyboy's build thread if you haven't already. He's done some nice work with his. 

 

http://comancheclub.com/topic/16226-mnkyboys-89-comanche-project/page-28

 

 

 

gears are your best bang for your buck.  choose them wisely :D

 

 

gears + boost =   :banana:

 

I checked out his thread and that supercharger set up is crazy haha. I would first have to swap my tbi to mpi before I can think about supercharging my motor. That's why I was thinking of stroking it, I know its beating a dead horse  :yes:  now my I'm considering boost lol

I was planning on going with 5.13 gears with a 5sp and 35s. I was going to go 4.88s but I was afraid they would not be enough

[SBpunk]

 

 

Does anyone know anything about stroker kits for the 2.5l? I have done some research and this company called 505 performance

 

  I don't think stroking a 2.5 would do much good. You would get more bang for the buck with a supercharger. Check out mnkyboy's build thread if you haven't already. He's done some nice work with his. 

 

http://comancheclub.com/topic/16226-mnkyboys-89-comanche-project/page-28

 

 

 

gears are your best bang for your buck.  choose them wisely :D

 

 

gears + boost =   :banana:

 

I checked out his thread and that supercharger set up is crazy haha. I would first have to swap my tbi to mpi before I can think about supercharging my motor. That's why I was thinking of stroking it, I know its beating a dead horse  :yes:  now my I'm considering boost lol

I was planning on going with 5.13 gears with a 5sp and 35s. I was going to go 4.88s but I was afraid they would not be enough

 

5.13 you'll need a new front axle since D30 only allows up to 4.88. Even with 4.88 you're running a very small pinion. On 35s an 8.8 or 9 inch would probably be a safer bet. As for the front you'll have to ask around.

[mnkyboy]

Revolution gear makes 5.13s for the D30.

 

I had 4.88s with the TBI 2.5l and 33s, it worked pretty good especially since i had been running stock 3.55s with 33s before,it was a huge difference.

 

When i built the MPI engine i went to 5.38s and 37s,it pulled good even before the supercharger.

[Swampy]

Revolution gear makes 5.13s for the D30.

 

I had 4.88s with the TBI 2.5l and 33s, it worked pretty good especially since i had been running stock 3.55s with 33s before,it was a huge difference.

 

When i built the MPI engine i went to 5.38s and 37s,it pulled good even before the supercharger.

 

I think there is a few companies that make 5.13 gears for the d30.  A few guys over on pirate have been running 5.13 gears locked and haven't had an issue. 

[mnkyboy]

There have been 5.13s for the JK D30 for a while but they are different.

 

Revolution gear is the only company as far as i know that is making them for the older D30.

[Swampy]

I don't know how put the d30 I have is a high pinion non vacuum ( it doesn't have the disconnect on the passenger side axle tube) out of an 88 Cherokee wouldn't be the same as all the other xj front axles? 

[mnkyboy]

All XJs with a full time transfer case got the non disconnect D30.

The disconnect D30 was used in 84-91 XJs with a part time case.

 

Both versions were high pinion, yours is probably from an XJ that had a 242 transfer case.

[Swampy]

All XJs with a full time transfer case got the non disconnect D30.

The disconnect D30 was used in 84-91 XJs with a part time case.

 

Both versions were high pinion, yours is probably from an XJ that had a 242 transfer case.

 

Yeah the xj has a 242 case and that is going in the Comanche as well. So the front axle is the non disconnect version?

[mnkyboy]

It will be a non disconnect but unless it has ABS it will have the smaller Spicer 5-260X joints.

 

It's not a big deal though as the larger 5-297X/5-760X joint shafts will drop right in.