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So theoretically the Cummins r2.8 turbo diesel will fit in our trucks, if the Cummins site is correct in their measurements that is, but surprisingly I havent seen any info on anyone that has done it with an MJ or XJ. Their crate engine kit comes with an entire harness, the ECM, a pedal, fuel pump, and a modular oil filter housing. It really seems like you wouldn't need much to swap it in other than drafting up and making some custom engine mounts but is it worth it? For an $8k price tag it certainly seems steep but if your 4.0 is already dead or on its way out and you want your MJ to last long enough for your grandkids to enjoy it is diesel a good choice? Compared to a 4bt swap which ive seen done a few times, it weighs about 350lbs less, and has a much smaller form factor. Its a 4 cyl with about 161hp but puts out a whopping 310lb ft of torque at 2000 rpms. To me that screams much better mpg and much better offroad capability. Ive seriously been considering saving up on the side for a swap like this but I'm curious to know everyone elses thoughts on it. Its also worth noting that my current trans/t-case (AX15 and NP231J) are both rated by cummins to be able to handle the engine so I wouldn't even need to hunt down something like an NV4500 like I would if I wanted to do a 4bt swap.

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If money were no object I'd already have one in one of my MJs. :D 

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Ya, I think it's the price tag on em right now...

I love my 3.3L Cummins swap. 85hp/215tq with an ax15.

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2 minutes ago, Pete M said:

If money were no object I'd already have one in one of my MJs. :D 

I hear that, have you done any research at all into how they would fit in our trucks? I know they need a charged cooling system thanks to that turbo so making it all fit would be the trickiest part. But hey if they can fit in things like CJ5's as ive seen before then it should most definitely fit in our trucks right? 

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Just now, krustyballer16 said:

Ya, I think it's the price tag on em right now...

I love my 3.3L Cummins swap. 85hp/215tq with an ax15.

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do you have a build page? Id love to see how that all came together :D

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Ya. Search 3.3L Cummins in the epic section. Some pics might be lost but I can send any if interested.

Or Facebook message with questions

Brandon Scarbrough

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12 minutes ago, krustyballer16 said:

Ya. Search 3.3L Cummins in the epic section. Some pics might be lost but I can send any if interested.

Or Facebook message with questions

Brandon Scarbrough

Sent from my SM-G973U using Tapatalk
 

that was a cool read, now how much for you to do it again with someone elses jeep haha 

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The engine, truck, tranny, $800for the tranny adapter, $1500 more for misc parts, and $1500 for labor and 4 months lol

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On 10/11/2019 at 3:19 PM, Pirate_Staz said:

I hear that, have you done any research at all into how they would fit in our trucks? I know they need a charged cooling system thanks to that turbo so making it all fit would be the trickiest part. But hey if they can fit in things like CJ5's as ive seen before then it should most definitely fit in our trucks right? 

 

You'd think this would be the case, but it's usually not.  CJ5's (and most wranglers) are narrow and tall in the engine bay...MJ/XJs are short and wide, which makes some things more complicated, sadly (at least if you want to keep the stock hood lines).

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15 hours ago, thecodemonk said:

 

You'd think this would be the case, but it's usually not.  CJ5's (and most wranglers) are narrow and tall in the engine bay...MJ/XJs are short and wide, which makes some things more complicated, sadly (at least if you want to keep the stock hood lines).

Hmm thats true, i know the 4bt is really tall but i think thr r2.8 isnt too tall of an engine, id definitely email cummins and see what they think about the install before hand just to ensure everything will fit with minimal cutting

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Hmm thats true, i know the 4bt is really tall but i think thr r2.8 isnt too tall of an engine, id definitely email cummins and see what they think about the install before hand just to ensure everything will fit with minimal cutting
Compare dimensions of the 2.8 to the 3.3...
If they're similar then it should fit with no cutting, since much 3.3 fit just fine.

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I've been looking at the R2.8 for a while.  I can't do it in my XJ because it's only smog legal through 1999 and my XJ is a 2001.  I had looked into it for my J10 pickup but with only just over 300 ft-lbs, it's not enough for what I'm going to do with it.  Being based on the ISF series engines, there is a 3.8 liter in the family that would be much better for my J10 as it would be over 400 ft-lbs where I want it.  But I haven't heard diddly about Cummins releasing an R3.8. :(

 

Axis Industries has a bunch of parts available to support the 2.8 swap, especially in Jeeps.  They have an adapter that makes it an AMC bolt pattern so your AX-15 or NV3550 will bolt right to it, complete with OEM flywheel (I think).  You can bolt an AW4 to it but you have to figure out a way to control it.  You have to figure out how to make the throttle by wire work with the mechanical throttle position cable that attaches to the transmission.  The CAN bus has all the data you need to control the shift solenoids but I'm not aware of anyone who has programmed a controller to do the work.  Yet.  They also have brackets to deal with narrow frames like you find in Jeeps and the impact that has on accessory placement.

 

The intercooler, to me, seems like one of the biggest hurdles for the swap.  With the wide and short grille on the XJ/MJ, routing the hoses is "difficult".  The air box and battery are both in the way.  One alternative is an air-to-water intercooler.  You can put the radiator out in front but still behind the grille and then run hoses to a heat exchanger under the hood, along with the pump to cycle the antifreeze.  With 2 fewer cylinders, you probably have room to fit it somewhere. 

 

I'm not sure about the inlet/outlet for the water pump but between the Jeep setup and the available Chevy swap radiators that switch sides, you're probably covered.  And you're likely going to work in dual electric fans, probably just have two stock fans side by side.  I believe the engine controller can run them just fine (with a relay).

 

I haven't ruled out a 2.8 swap in my MJ project but with all of the other things I want to do, I may just stick with a 4.0 until I have it out on the trails for a while.  Conservatively, I estimate that a 2.8 swap with all of the extra stuff you need can't be done for less than $15,000.  A $20,000 budget is probably more reasonable.  And that's if you keep your AX-15/NV3550.

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that is some heavy duty research derf, and it definitely helps point me in the right direction. I think youre probably right about the price as i estimated about $18,000 so its definitely an expensive build, one for when I start makin more than I am now (anyone looking for a mechanical/electrical drafter?) but if it ensures my MJ stays on the road for another 33 years with no issues then I see no problem sinking that kinda cash. Diesels are cool but my main goal is to keep my MJ as a daily for the rest of my life if possible lol. Sure a 4.0L replacement is much cheaper and easier when mine dies but  the added power off road and mpg improvements are enuf to convince me. New cars are too complex and boring anyways id rather put that money somewhere else like a cool swap.

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I see more r2.8 swaps come out of sponsored shop builds. It seems like a fun swap and would definitely be something I consider for my comanche. Only issue is price. ANY SHOP SPONSOR WANT TO BUILD MY COMANCHE??? :roflmao:

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I am looking to do the same, but as everyone else said, its the cost. On the other hand go over to https://www.naxja.org/forum/showthread.php?t=1150520 its a XJ site, and there is alot of useful info about the Cummins 2.8 and 4bt. but what caught my eye ( i don't think an MJ could handle it) but there is a 6bt swapped XJ. The owner redid the entire frame so that it could work. But let him do the talking.

 

This is a pic from his post.

 

29952002977_ea6d23e938_c.jpg

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