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Best Diesel swap options

109K views 20 replies 14 participants last post by  goincommando 
#1 ·
Howdy folks,
I have pretty much decided to go ahead with a diesel swap to replace my 2.5L and AX-5. So, I am trying to get a list of diesel engine options to choose from. I have seen a few various write-ups but information is less than consistant regarding these swaps. So far, 4BT paired with an nv4500 seems the best choice, but I really dont know what benefits the other diesel swaps may have. A lot of the guys say the 4BT is too heavy, while at the same time I've seen a few writeups on 6BT swaps even.
The main advntages I'm looking for is the huge increase in torque followed by way improved fuel economy. I don't want to sacrifice all off-road capability for 40 mpg by any means (for instance the small merc engines), so I'm looking for a nice compromize. 6BT seems pointless to me since its so heavy and I dont ever do much of any towing.
I appreciate any input y'all may have, thanks in advance.
 
#2 ·
A 4BT is great, a little heavy but great. A Cummins 3.3 a smaller lighter 4cyl is another popular swap in Jeeps. I think you can get a brand new 3.3 for under $4000. I am in the middle of a Mercedes 5cyl turbo diesel swap. Not as much power but for me it was priced right at $100.
 
#16 ·
Sofim 2.5l direct injection turbo



We have available a complete diesel conversion ( 4cyl diesel direct injection turbo) kit for the wrangler Yj 6 cyl manual ax15 only because the stronger gearbox,bigger radiator and air filter and clutch.
The kit was made in Italy by IVeco.
I'ts a Military version with close distribution.
Electric fan,all supports,hoses etc.. and a special front subframe are included in the kit.
Price 3400€
 
#3 ·
It's not the engine that cost so much as the parts that are added to get everything to work. :laugh:
 
#4 ·
For me I bought a whole Mercedes 300sd for $100. From the engine back is all jeep making parts easy and cheaper to find. I bought a bellhousing/flywheel adapter for $350. An AX-15 and T-case to swap out my BA-10 and T-case for $250. So for an almost rust free 88 YJ and a swapped turbo diesel, I have less than $1500 total including the YJ.

Most similar swaps will be the same. An adapter plate and if there are clearance maybe a 4" lift. If you beat on it then maybe a NV4500 and an Atlas 2. It can get very expensive if you are extreme and beat on everything.
 
#6 ·
The Isuzu 4BD1T is also an option. Essentially a japanese version of the 4BT.

It is a smidge heavier than the 4BT but puts out very comparable numbers. It seems to be a little easier to find for a decent price (at least in my area). They were used in the Isuzu box trucks up through '99 I believe. After that, they used another 4 cyl diesel but it got much heavier and had electronics for the fuel delivery.

Hope that helps a little. Do us all a favor and put together a good write up when you get going on this.
 
#7 ·
Another note.

The NV4500 is a great transmission but it is also ridiculously long (~19") compared to the AX15 (16.5"). This can start to create drivetrain nightmares very quickly.

If a rear stretch is in your plans, then don't fret but just make sure that you take all of this into account.

Some will call for my crucifixion for this but here goes; you don't need to have an overdrive transmission for all applications.

Yes, diesels don't have a huge rpm range but combined with proper gearing and larger tires, a really tough 4 speed transmission like the SM420 or the SM465 can be used. The SM420 actually has a larger gearing range than the NV4500 as well. They are lighter, shorter (~12") and considerably cheaper than the NV4500 as well.

If your plans don't include gearing and tire changes, please disregard this post :D
 
#10 ·
One of my friends is dropping a om617 mated to a 700r4 in his yj right now. probably the biggest issue is the oil pan that sits right in front. He's going to stretch the wheelbase to help it out. Here's a pic.

 
#12 ·
Hi all

I've done a lot of research on this type of swap over the years and the consensus of that research is as follows:

1.) 6BT-Way too heavy unless one wants to reinforce the frame, drop 3/4 ton axles on their rig. The weight of the engine alone is plus 1000 pounds

2.) 4BT-The little brother to the 6BT; found in bread trucks and generators all the type. Fits much better than 6BT but shakes likes a demon unless mounted on fluid mounts and is a noisy little sucker. Weighs around 750 lbs

3.) GM 6.2 or 6.5 V8 Diesels-Tons of them out there for good or bad. Not that difficult a swap as they utilize GM mounts and conversions. They run hot though so a radiator swap will be needed. Here is a fellow who threw one in his Wrangler

http://www.thedieselpage.com/readers/fleming.htm

4.) As some here have already mentioned the Mercedes OM617 swap is gaining popularity due to size and weight. In fact, I've recently come across a fellow making the motor mounts and adapters to throw this in a YJ plus a lot of the technical info. Check him out here:

http://mercedesdiesel4x4.com/default.aspx
 
#13 ·
1) It has been done but in my opinion it's too big and heavy!
2) Love a shaking 3.9 4BT but gaining popularity and the prices are going through the roof!
3) Is a great idea. Most think the (Detroit Diesel designed) 6.2 and 6.5 are slow boat anchors but I like them. They have some power, are cheap and easy to find, parts are cheap and bolt up to any Chevy bellhousing.:D
4) Is what I'm doing. I got the whole running 300sd for $100. :wave::cheers2:
5) A Cummins 3.3 It is also expensive unless you are lucky to find a used on. It is lighter and still has power and can be tuned. It's mainly an industrial engine

This is where I got my adapter. You don't have to stretch the frame it's an I5 and the 4.0 is a I6 so the I5 is shorter.

4.) As some here have already mentioned the Mercedes OM617 swap is gaining popularity due to size and weight. In fact, I've recently come across a fellow making the motor mounts and adapters to throw this in a YJ plus a lot of the technical info. Check him out here:

http://mercedesdiesel4x4.com/default.aspx[/QUOTE]
 
#14 ·
one thing if you wanna make this build easier is not to go with an electronic deisel engine that has common rail injection or heui (hydraulic electronic unit injection) go with something that an inline multiple pump or unit injection because then you don't have to worry about spending more on a brain, wiring harness and all the sensors. good luck on all your guys' builds ! ROLL SOME COAL! xD
 
#15 ·
Got one more for ya....especially if you've got the cash and want to go Electronic diesel

Check this out

http://www.hpamotorsport.com/tdijeep.htm

Crazy expensive put the parts are everywhere for this thing......

Other than that, I totally agree with SuperDuty59 and rebelsonjeep on choices.

I really think more and more the way to go is the OM617 or GM 6.2

ON the OM617 only issue being the cost to mod the IP for more fuel. It can be done but its tricky for fuel upgrades which boots power big time.

The 6.2/6.5 biggest issue is heat...and lots of it....
 
#18 ·
I'm not overly familiar with automotive diesels, but have some experience with marine diesels.

Out of curiousity, has anyone done or looked at something like the old GM 3-53 engines or maybe Yanmar, Volvo, or MAN? Way back in my early USCG career we had 30 footers with the 3-53 and as I remember it was pretty compact and nice and responsive to throttle inputs when manuevering in close quarters.
 
#20 · (Edited)
CJ with Isuzu NKR Diesel engine

Hello Jeepers

Writing from Costa Rica

I'm getting involved with a swap on my Jeep Wrangler TJ 1999 with a Nissan Terrano 2.7 diesel engine known as TD2.7 a friend of mine years ago swap the engine in a YJ Wrangler the engine came from a Nissan Terrano TD 2.7 with the complete transmission, this swap is very particular since the differentials and transmission are well align and there is not much work involved.

Here in Costa Rica Swaps are known in some competition vehicles

There is a CJ7 with a Isuzu NKR 4 cylinder engine who was champion for a few years on a race called "El desafio" here in Costa Rica

This is a couple of video of the guys riding

Video in the one of the races



This is the CJ7 sound CJ7 with NKR Diesel Engine

 
#21 ·
I'm currently putting an om617a turbo diesel into my 89 yj, 85 mercedes 300d puts out 125hp and about 180 tq, you can bump it up a lil, but no major gains. My prob was firewall clearance but a healthy stress work out later and she's in, going to run electric fan, and figure out how to snorkel it but its looking better every day...om617 with mercedes4x4labs adapter to ax15/np231 and 3.73or4.10's 3"body lift to mount motor high and 3" suspension to completely clear front diff

Weight of mercedes is a few lbs more than 4.2
 
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