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Cummins 5.9

B

bullardsbarbarian

NAXJA Forum User
Location
Dobbins, ca
I've been thinking about putting a Cummins in my xj for a long time now, and was wondering if any one has ever tried it before. I know that the whole motor package with inter cooler and radiator is longer than will fit in my engine bay, but I'm not afraid to do some serious uniframe/body work to make it fit, be roadworthy and still look stock to the untrained eye. I'd also use the rest of the drive train from a dodge truck (severely modified to fit of course). I think the only problem that I have any reason to worry about is I'm in California. That means some pretty strict rules on engine swaps. This is very hypothetical and probably a few years off, but I want to look into it. Any suggestions/ideas?
 
5.9l 12v, 24v or 3rd Gen HPCR?

Any way you look at it, you're looking at over 1,200 lbs. over your front axle. It's long, and it's tall.
 
ChiXJeff said:
5.9l 12v, 24v or 3rd Gen HPCR?

Any way you look at it, you're looking at over 1,200 lbs. over your front axle. It's long, and it's tall.
Click to expand...

4Bts have trouble fitting in the engine bay, I cant imagine the work to fit a 5.9 in there.

You will need serious unibody work, perhaps even lengthen the hood area. Maybe a cowl hood as well. Its just a huge engine.

Then you will need some suspension work to make it support the extra weight you threw in the front.
 
CherBear said:
4Bts have trouble fitting in the engine bay, I cant imagine the work to fit a 5.9 in there.

You will need serious unibody work, perhaps even lengthen the hood area. Maybe a cowl hood as well. Its just a huge engine.

Then you will need some suspension work to make it support the extra weight you threw in the front.
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How much weight are we really talkin' here? The 4.0 is a fairly heavy engine to start with. I know that the Cummins is heavier, but suspension work is not a big deal to me. As far as the length is concerned, I was planing on cutting the fenders and hood to add some sheet metal anyway. And IF this happens, I'll be building a custom frame(or hacking up a truck frame AND my xj) to make this all work. I'm not sure about the hight though. I'll take measurements on my work truck tomorrow to see the difference. Thanks very much for the info.:thumbup:
 
4BT definitely possible, but I would just go with an LSx motor.
 
i say move the firewall back and get a cowl hood, but before you even start, get a cage and some frame stiffys, unless you really like twizzlers. you oughta leave the dana 35 in there until it breaks, just as an experiment, though...:D you'll also hafta remake your transmission hump, and as said above, you'll need some really stiff springs, or it'll be riding on bumpstops fulltime.
 
4bt all the way. the 6 is just too huge to go into an XJ and it still look remotely stock. Sounds cool but I bet that engine has a couple hundred pounds on the already heavy 4.0!
 
bullardsbarbarian said:
How much weight are we really talkin' here? The 4.0 is a fairly heavy engine to start with. I know that the Cummins is heavier, but suspension work is not a big deal to me. As far as the length is concerned, I was planing on cutting the fenders and hood to add some sheet metal anyway. And IF this happens, I'll be building a custom frame(or hacking up a truck frame AND my xj) to make this all work. I'm not sure about the hight though. I'll take measurements on my work truck tomorrow to see the difference. Thanks very much for the info.:thumbup:
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The block alone on a 5.9l ISB weighs over 800 lbs.
 
I don't think the unibody could handle the weight/torque from a 6bt. A local shop to me has put a 4bt in at least one Xj, along with Cj'c,YJ's, and TJ's. The shop is Jeff Daniels Jeep Customizing in Harleysville, PA. Wrong side of the country but it couldn't hurt to contact them. http://www.jeffdanielsjeeps.com/
 
If your XJ is going to be street driven, there is no way (if I'm interpreting the law correctly) to put a 5.9 Cummins in one and still be able to register it as a Cherokee. The emissions mandate requires that the donor and recipient must be of the same class of vehicle. I know it's possible to get away with engines avilable in 1/2 ton trucks, but the Cummins only comes in HDs, 3/4-1 ton trucks. I think they might have a problem with that.

Not to mention how the heck you expect to fit that beast under the hood and still have room to get in. The 4.0 Takes up all available length, and required modification to the chassis to fit under the hood. A 4.0 won't fit in a stock 84-86. There was someone on here who did it and he had to swap most of the donor vehicle's front end over to fit the 4.0.
 
Try a liberty 2.8CRD that'll fit.
 
Although more money, a CRD would be a better option. Maybe find a wrecked newer GC with a CRD and swap it over?
 
The 5.9 is 1010 lbs, the 4.0 is around 550 lbs. So thats nearly a 500lb increase in weight.
I would go with a 4bt if you really want a diesel, the 6bt swap would just be nearly impossible, much less emission legal.

Really, the only feasible way I can imagine is you getting a dodge frame with the 6bt, then start by shortening it to fit the wheelbase of the XJ. Then its just a matter of body work, LOTS of body work.
 
CherBear said:
The 5.9 is 1010 lbs, the 4.0 is around 550 lbs. So thats nearly a 500lb increase in weight.
I would go with a 4bt if you really want a diesel, the 6bt swap would just be nearly impossible, much less emission legal.

Really, the only feasible way I can imagine is you getting a dodge frame with the 6bt, then start by shortening it to fit the wheelbase of the XJ. Then its just a matter of body work, LOTS of body work.
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Yes, but putting an XJ on a frame never turns out good!
 
FlexdXJ said:
Yes, but putting an XJ on a frame never turns out good!
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No it doesn't. It CAN be done, but never seems to work out. That is why I recommend the 4bt swap.

You can still get huge amounts of power from that engine, I mean they put those engines into 1 ton delivery vehicles. Im sure it will give you plenty of power, not to mention they are torque monsters.

You will still need suspension work as well. The 4bts are at about 800lbs.
 
CherBear said:
No it doesn't. It CAN be done, but never seems to work out. That is why I recommend the 4bt swap.

You can still get huge amounts of power from that engine, I mean they put those engines into 1 ton delivery vehicles. Im sure it will give you plenty of power, not to mention they are torque monsters.

You will still need suspension work as well. The 4bts are at about 800lbs.
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If I do a 4bt, I am getting a CJ to put it in. My cousin is planning on swapping a 4bt into a TJ as well!
 
Flex have you seen the Brown CJ with the 4bt running around town. It is sitting on 1 tons and sits up where Gene works.
Cardboard
 
cardboard said:
Flex have you seen the Brown CJ with the 4bt running around town. It is sitting on 1 tons and sits up where Gene works.
Cardboard
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Yeah that thing is amazing. I think his name is Steve. I think he graduated a year before me. I was confused when I saw it up close. I didn't see a T-case lever but its got a t-case and driveshafts attached to the 60's under it! Thats what made me want a 4bt in a CJ! So thats where Gene's shop is, I was wondering where it was!
 
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it is pointless to put a 5.9 cummins in it, it is way to much work and way to heavy, a 4bt is a much better option and all most all of its parts are interchangeable with the 5.9 i have a 5.9 p-pumped 24v cummins in my truck. my plan has always been to swap in a 4bta with the p pump on it into my xj. they make great power there is a guy with a ranger that has a 4bt that is making 800 hp on fuel im big into diesels glad to see more interest go to WWW.4btswaps.com
 
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