Cummins swap
- Thread starter MOAK
- Start date
x32792
Adventurer
I've flirted with the idea of putting a diesel in my TJ, researched several options and have decided against it.
For the TJ, the Cummins 4bt swap requires extensive bumper-to-bumper modifications involving the frame, suspension, cooling system, electrical harness, instrumentation, drive train, transmission, transfer case, etc, etc.
The final results depend greatly on the skills of the person(s) doing the swap and are often expensive unless you do the work yourself and get the parts for free.
The 4bt swap will produce more torque, more noise, more vibration and better milage. It will also require the services of master mechanic who understands how it was put together to keep it running or make repairs.
And then there's the issue of breaking down in the middle of Nowhere in a highly modified machine.
For the TJ, the Cummins 4bt swap requires extensive bumper-to-bumper modifications involving the frame, suspension, cooling system, electrical harness, instrumentation, drive train, transmission, transfer case, etc, etc.
The final results depend greatly on the skills of the person(s) doing the swap and are often expensive unless you do the work yourself and get the parts for free.
The 4bt swap will produce more torque, more noise, more vibration and better milage. It will also require the services of master mechanic who understands how it was put together to keep it running or make repairs.
And then there's the issue of breaking down in the middle of Nowhere in a highly modified machine.
jeepdreamer
Expedition Leader
All good and valid points. Since you already own a CRD LIB you are at least somewhat keyed in to the differences of Diesel vs Gas motors. The 4BT is a great engine. Potential for really good MPG numbers and drivable HP/Torque. But it is not an easy to live with choice. First, it will be expensive...VERY expensive. Depending on what your putting it in that is. Have an old J-truck or Wagoneer laying around.?. Good candidate. Wanna drop one in your TJ? Break out the check book and say goodbye to several things...
Like resale value.
Ability to get a title/plate/emissions...
Having a normal conversation with the top up and doors on.
Not trying to disuade you...if you want to build something...go for it! But as much as I like the 4BT I don't think it would make a very good candidate for a swap as a DD in a "nice" rig. Not saying it CAN'T be done...but the amount of dollars to make it there would make a solid axle swap in your LIB look like pocket change!
x32792
Adventurer
4bt in TJ
Here's what a 4bt in a TJ looks and sounds like:
[ame="http://www.youtube.com/watch?v=t9ULDv7vCKs"]YouTube- 2000 Jeep TJ 4BT Cummins 3.9L[/ame]
Done by Overland Diesel: www.overlanddiesel.com for more details.
Here's what a 4bt in a TJ looks and sounds like:
[ame="http://www.youtube.com/watch?v=t9ULDv7vCKs"]YouTube- 2000 Jeep TJ 4BT Cummins 3.9L[/ame]
Done by Overland Diesel: www.overlanddiesel.com for more details.
Warhead
Adventurer
I have been toying with the idea of putting a 4BT in my MJ, the major downside is the cost since everyone & their brother is looking for the cummins the prices have shot through the roof.
I can almost do a complete LSx swap(doing the work myself) with transmission/adapters/ECU reflash/ect. for just the cost of the 4BT.
I would think with a 5.3 LS in my MJ 20mpg+ should not be a problem and 350+HP won`t hurt either:victory:
5.3L in a XJ
PS I don`t know why this guy did not change the truck intake manifold to a car intake manifold, it would have made room for the hood to close.
I can almost do a complete LSx swap(doing the work myself) with transmission/adapters/ECU reflash/ect. for just the cost of the 4BT.
I would think with a 5.3 LS in my MJ 20mpg+ should not be a problem and 350+HP won`t hurt either:victory:
5.3L in a XJ
PS I don`t know why this guy did not change the truck intake manifold to a car intake manifold, it would have made room for the hood to close.
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KLAKEBRONCO
Adventurer
With some research the 4BT is without question going to be easier to service and keep running in top condition than the stock gasoline engine. The 4bt is stone simple, and that's part of their appeal.
I've looked into a diesel swap for my fullsize Bronco. To me, it just doesn't make sense. The stock powerplant makes plenty of power for me. And when all is said and done I'll be pushing 20mpg with 35's.
I might get 25mpg out of the diesel, but the cost to swap will be HUGE, especially considering with the gas engine I'll keep parts of the drivetrain that would need to be upgraded with the diesel.
Where I live diesel is currently 30 cents more per gallon and has been as high as a dollar more per gallon. The benefit to cost is WAY out of wack. LOL:Wow1:
Even the 4bt is VERY heavy, and probably close to two 4l I6 engines.
I've looked into a diesel swap for my fullsize Bronco. To me, it just doesn't make sense. The stock powerplant makes plenty of power for me. And when all is said and done I'll be pushing 20mpg with 35's.
I might get 25mpg out of the diesel, but the cost to swap will be HUGE, especially considering with the gas engine I'll keep parts of the drivetrain that would need to be upgraded with the diesel.
Where I live diesel is currently 30 cents more per gallon and has been as high as a dollar more per gallon. The benefit to cost is WAY out of wack. LOL:Wow1:
Even the 4bt is VERY heavy, and probably close to two 4l I6 engines.
Warhead
Adventurer
the 4BT is a tall engine and in an XJ/MJ will require at least 4" of lift for oil pan clearence(I would think it would be the same in a YJ/TJ/JK)
The LSx motors are actually a good bit smaller(length) then a I6(4.0L) and an aluminum block motor is lighter too. The 4.0L is about 525lbs & the LSx is about 490lbs.
Novak now makes just about anything you would need to put a LSx in any Jeep.
another XJ, this one with a car intake
the only thing I would change is the air filter location(I would make some type of air box to keep out water)
max adams
Observer
http://www.jeepkings.ca/forums/showthread.php?108747-Lifted-2000-Jeep-TJ-2500-must-go-asap
The actual TJ in the youtube vid is for sale, has been for a while. Now he's parting it out.
The actual TJ in the youtube vid is for sale, has been for a while. Now he's parting it out.
jesusgatos
Explorer
I considered putting a 4BT in my old CJ7 a long time ago, but ended up with a fuel-injected 300hp MOPAR 360 crate engine instead. Like others have already pointed-out, the cost/benefit makes it hard to justify unless you're planning on putting a LOT of miles on your truck, or just plain down care about the expense. Weight was the other thing that made me think twice about that swap. In a SWB rig, I just didn't want to deal with the front/rear weight balance being that far off. Love the idea though, and I can think of several projects that I would choose to use that engine in.
x32792
Adventurer
4BT in Hummer HI
http://www.youtube.com/user/jamieavant
H1 Hummer with 4BT Cummins from Diesel Depot
Another custom 4BT Cummins powered H1 Hummer conversion from Diesel Depot. This 1992 H1 originally came with a 6.2L GM diesel and a th400 non-overdrive automatic transmission. Now it has a 4BT 3.9L Cummins with an HY-35 Holet turbo, high-flow injectors, and a 3200 RPM governor spring, and ceramic coated pistons. Also, we installed an overdrive 4L80E transmission with a full manual shift valve body.
http://www.youtube.com/user/jamieavant
H1 Hummer with 4BT Cummins from Diesel Depot
Another custom 4BT Cummins powered H1 Hummer conversion from Diesel Depot. This 1992 H1 originally came with a 6.2L GM diesel and a th400 non-overdrive automatic transmission. Now it has a 4BT 3.9L Cummins with an HY-35 Holet turbo, high-flow injectors, and a 3200 RPM governor spring, and ceramic coated pistons. Also, we installed an overdrive 4L80E transmission with a full manual shift valve body.
cruiseroutfit
Well-known member
Looks no further than 4BTswaps.com, its the one and only source you'll need for information on the 4BT swap. Literally hundreds of them in Jeeps, Land Cruisers, cars, you name it. Furthermore its run by ExPo member dieselcruiserhead whom has done a few 4BT swaps himself.
I don't know where you are in PA, but Jeff Daniels Jeep in Harleysville (http://jeffdanielsjeeps.com/) has done several 4BT conversions. I talked to them a bit at the York All Breeds show and they were talking about the possibility of a kit soon. I've also been considering a diesel in my LJ one day ...
MOAK
Adventurer
thanks all;; yes, I've spoken to the folks at Jeff Daniels, and wow, I am a diesel head, no doubt, but, just way too many mods to get there, and it drives the price way out of line, I love the idea of lots of torque @ 1600 rpms, but jeeze 3.07's replacing the 4.11's,, still means peak torque @ 60 mph, everything after that is diesel out the stack. On paper it all looks real good, practical,, ooops!! Long range expeditions means I want to travel @ 65 to 70mph on highway, and with the 4bt an ideal operating rpm would be around 1400rpms @ 65 mpr, unattainable without swapping in much taller gears everywhere. Then look out, the beauty of the low gearing of the rubi would be lost. I'll just be patient, and hopefull a bolt in kit will someday be available for the 2.8l Motori CRD. A much easier matchup to my driveline! Thanks all for your input.
