Cummins swap discussion

[john adams]

I've seen a few people here suggest that when their Ecodiesel engine dies (or before), they might swap out for a Cummins. A few questions from someone who never swapped a diesel engine:

1) How possible is this? I mean, is this a realistic option to keep the vehicle going? OR is this going to create more problems since the Wrangler isn't built for that engine?
2) Someone suggested a total parts and labor cost of $15,000. Does that sound realistic?
3) Would that significantly prolong the life of the vehicle? I know the engine would be good after that, but would it be putting a 13 year old's heart in a meth addicts's body? Meaning, would this effort be worth it while the rest of the Jeep falls apart?

I like my 2023 and I'm already at 50K no-issues miles...but Jeep has a dubious reputation.

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[mwilk012]

If you have to ask, triple the price.

No, it’s totally unreasonable. It’s like suggesting a hellcat drop in replacement for a 3.6. It’s going to be very, very expensive, and lots of things are going to have to be modified or outright removed.

It has been said a 5.9 Cummins can technically fit, a 6.7 isn’t happening.

 

[Maverick909]

you should be capable to install a small 4 cyl Cummins in. we all have seen Fred Williams do it in a TJ. Now as for the cost who knows without tons and tons of research but it is possible. I am planning on installing a 5.7Hemi v8 into my JL when the 3.6 goes.

 

[mwilk012]

you should be capable to install a small 4 cyl Cummins in. we all have seen Fred Williams do it in a TJ. Now as for the cost who knows without tons and tons of research but it is possible. I am planning on installing a 5.7Hemi v8 into my JL when the 3.6 goes.

You have a lot of engine swap experience?

 

[Maverick909]

You have a lot of engine swap experience?

yup sure do, rebuild cars as a hobby. i also design and build aerospace furnaces for a living. Cars and trucks are easy

 

[mwilk012]

yup sure do, rebuild cars as a hobby.

Then you should know how unreasonable it is.

 

[Maverick909]

Then you should know how unreasonable it is.

i find you love to just argue with everyone. who cares. it can be done and has been done may times with the JK's and even LS swaps are being done with the JLU's everyone has their own take on what they want. its just money.

 

[Ratbert]

I've seen a few people here suggest that when their Ecodiesel engine dies (or before), they might swap out for a Cummins. A few questions from someone who never swapped a diesel engine:

1) How possible is this? I mean, is this a realistic option to keep the vehicle going? OR is this going to create more problems since the Wrangler isn't built for that engine?
2) Someone suggested a total parts and labor cost of $15,000. Does that sound realistic?
3) Would that significantly prolong the life of the vehicle? I know the engine would be good after that, but would it be putting a 13 year old's heart in a meth addicts's body? Meaning, would this effort be worth it while the rest of the Jeep falls apart?

I like my 2023 and I'm already at 50K no-issues miles...but Jeep has a dubious reputation.

You're in PA, so I'm pretty sure the emissions standards of the replacement engine have to meet or exceed those of the original. Your inspections might also become challenging.

 

[Ratbert]

i find you love to just argue with everyone.

You're rather observant.

 

[mwilk012]

i find you love to just argue with everyone. who cares. it can be done and has been done may times with the JK's and even LS swaps are being done with the JLU's everyone has their own take on what they want. its just money.

When the suggestions are to swap the entire powertrain instead of repairing/replacing the stock engine with comments like “it’s just money”, that isn’t helpful or reasonable.

I am under no obligation to agree with anyone unless they are objectively correct. Matters of opinion posted to a public forum are open for disagreement and you can feel about that whatever way you like.

 

[mwilk012]

You're rather observant.

Im not trying to be your Facebook friend.

 

[BuyHold]

If you are thinking about a used 4BT or something then maybe you can do this cheaper. Here is a R2.8 conversion kit for a TJ for reference. Includes the engine and all additional parts needed. Just shy of $20K for engine+parts.

https://www.axisindustriesusa.com/jeep-tj-r2-8-conversion-kit/

Also, I imagine there will be transmission mating problems given that JL auto transmissions are all computer controlled and need to be programmed to the engine to which it is mated.

 

[mwilk012]

If you are thinking about a used 4BT or something then maybe you can do this cheaper. Here is a R2.8 conversion kit for a TJ for reference. Includes the engine and all additional parts needed. Just shy of $20K for engine+parts.

https://www.axisindustriesusa.com/jeep-tj-r2-8-conversion-kit/

Also, I imagine there will be transmission mating problems given that JL auto transmissions are all computer controlled and need to be programmed to the engine to which it is mated.

The transmission would have to be replaced. Programming would be impossible for a DIY’er. You would almost certainly lose ABS functionality. In several states it would be illegal.

$15,000 isn’t happening, I’d estimate 35-40.

 

[jellis4148]

Not sure how hard the swap would be. I'm guessing a lot o front end upgrades would have to happen. If I remember correctly a 2nd gen 5.9 weighs around 1,000 pounds, and the ecodiesel only weighs around 500.

 

[grimmjeeper]

If you're thinking of swapping a Cummins from a 3/4 or 1 to Ram into a JL, you should reconsider. Just getting the engine to fit will require major surgery. It's a long engine that won't fit without a lot of cutting and welding. Dealing with the cooling stack on top of that is also a big challenge. There's no way you're going to have enough air flow to cool it without a significant redesign of the grill.

But if you really want to make it fit, it can be done with enough money.


A smaller diesel like the Cummins R2.8 is a lot easier to fit and has lower demands for cooling. Getting it to mate with the transmission and getting the computers to play nice with each other may be a significant challenge. Going with a different transmission and transfer case may be easier in the long run.

As has been mentioned, most of these swaps aren't exactly within emissions laws so depending on your location, they may not let you register the swapped vehicle.

Engine swaps can be a lot of fun. I've done a couple. Just be prepared to spend way more than you thought you would.

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