gearwhore

I am new here and new to jeeps, not new to custom vehicles though. I have recently become a very rapidly growing jeep fan and I want to get my first one. I have my heart set on a 4 door XJ and I need some advice from guys who have been there, done that.
- Question 1: I plan on using the rig for family camping trips and the occasional Moab run, it will hopefully be a DD if all goes according to plan. That being said, I am a pretty big diesel fan also and want to do a diesel conversion once the oem motor dies. What year model would be most complimentary to this customization?
- Question 2: If I do swap out the motor to diesel, would that mean that regular lift kits and springs would no longer be applicable to my rig? I understand that certain diesel engines weigh more than others but I would like to still be able to stick with as close to bolt on kits as possible so my time does not completely get eaten up by the project end instead of driving it. What types of diesel motors would fit the engine bay and weight around the same as the available oem engines?

Thanks ahead of time!

mjcxking

The 4bt cummins will fit your engine bay, it requires you to have a 3 inch leveling kit for it, I was going to do it but then I realized that it was going to cost me 7 grand including the engine and tranny, with a custom drive shaft and cross members, but they get pretty good gas mileage and are meant for torque

mjcxking

But if you did do the 4bt swap then you'll have and ultimate trail jeep and the engine will last longer then most of the stuff on your jeep, but yes you would be able to keep the bolt ons that aren't on your gas engine, you'll have to find a special shop that will do it for you, they will answer all your questions

gearwhore

I would love to do a 4BT swap, my main concern is the weight differences in the stock engine/tranny to the 4BT/(possible) 4L60E. I would love to be able to run 37's and get as much articulation as possible. While still maintaining DD mileage! Will bolt on kits like iron rock and TnT hold he weight difference without longterm consequences. I want to make sure I do it right the first time.

jburr94xj

They make Cherokees with diesels already in them. Just find one and lift it

cruiser54

mjcxking

The 4bt engine weighs around 725 and the 4.0l weighs around 450 pounds, so if that tells you anything and keeping the same upgrades it depends on how much you coil springs or leafs springs maximum load is

mjcxking

From what I saw is they have a wrangler with a 4bt in it and it costs 22 grand

jburr94xj

Cherokee comes factory with a 2.1L diesel

cruiser54

Only diesel XJ or MJ in the USA was around 1985 and had a Renault 2.1 in it. Yuk.

mjcxking

Ewwwww

gearwhore

From the research I've done the potential fuel milage after lift and decent sized tires was not much more promising than the gassers.

mjcxking

Everyone has there own opinions I know people with 6bts that say they get 18-20 and the 4bt has two less cylinders

gearwhore

What size tires usually? With what gearing? If its anything like what I have planned, I really like my odds!

salad

What kind of engine you want in there? Are we talking a Kubota ETVCS or an EMD 12-710G3B?

Cummins 4BT is a very popular swap with a ton of power, and as a result pretty good mileage in our little Jeeps. If you're just looking for something that rattles and takes juice from your deep fryer take a gander at the Mercedes OM617. Both have distinct strengths and weaknesses. Either one is a pain in the *** to get to work with an automatic because they're mechanical. If you have a standalone TCU for that transmission you can probably figure out a custom kickdown/TV cable and TPS. The OM617 is a front-sump design and warrants 3" lift to clear the pan with a 4WD XJ. I think the 4BT was available with front or rear. Not sure where the oil pump sits with the 4BT. There is a huge difference in torque between the two engines so your fab skills will be an important deciding factor. The OM617 is as close to 'bolt on' as you can get being as it's smaller and lighter, won't twist the uniframe to ****, and adapters are available to bolt right up to a factory AX-15.

Regarding years, diesel swaps are generally better in anything with an older dash IMHO. XJs newer than 1997 get dash info over the CCD bus from the PCM. Older ones you can probably rig up a tach much more easily.

The other thing to consider is emissions. In my area a practical diesel repower in a 2000+ is basically a no-go as the engine must be newer than the vehicle. However on my 1999 I just need to make sure "all factory emissions equipment is in place" and pass a smoke opacity test.

Take a look at www.4btswaps.com, there are a lot of Jeep projects over there. Here a "diesel swap" thread comes up every few months and then nothing happens lol. There are more blown XJs on here than oil burners.