3.9L 4bt cummins diesel swap

[ktmrider63]

Instead of originally swapping out my 2.5l 4 cyl for a v8 350, i'm getting more curious (and more excited, i LOVE diesels for some reason) about swapping in a 3.9l 4bt cummins engine in my 98 TJ.

I've looked around for other people that have done this, and there's quite a few, but nothing that's detailed enough to get a glimpse on what's required.

Does anyone know of any good sites that have any info on this type of swap?

 

[freedomfly]

I dont know of one but keep us posted. That would be sweet.

EDIT: After a quick google search I came up with this http://forums.dieselpowermag.com/70...swaps/39l-cummins-in-jeep-wrangler/index.html

 

[ktmrider63]

I found this rebuild:

Garrett's "Marshtackie" - My Jeep Club

And this website which has a lot of decent info, just haven't looked through all of it yet:

http://www.4btswaps.com/forum/index.php


And also, if I do swap in an older diesel into a 98 wrangler, won't that fail in an emissions test?

 

[Crazy4diesels]

The 4B is an awsome engine but... You'll need to do some pretty substantial mods to contain the torque. The rest of the TJ driveline is kinda weak for it - especially the Dana35 rear. Sure, you can drive around with it but if you boot it in a tough spot you'll likely have scrap metal coming out from under the poor Jeep. I have always wanted to do a diesel Jeep and had thought about swapping in the drive line from a early 80s Toyota diesel pickup. I don't know how well it would line up but it would probably perform pretty well. I can't say anything bad about the 4B, though - it's an awsome power plant!! One other thing... Check your local emission laws. A diesel TJ would be illegal here in Mass. Best of luck - John

 

[ktmrider63]

Yeah, i'd either be putting in a top notch dana 44 or a dana 60. I'm here in washington and I couldn't really find anything about diesel swaps for emissions. Though we do have about the same standards as california.

 

[jps4jeep]

there are also a number of people on Pirate 4x4 that have done this swap.. If you post over there, hold on to your nutz, cause they'll kick em in.

 

[Crazy4diesels]

If WA is like CA and MA for emissions I'm thinking a TJ won't pass as diesel. This is because there were no "light duty" diesel trucks allowed in those states at the time the TJ was produced. YJs and earlier are a different story. In CA I heard that they are converting YJs to diesel to keep them on the road. The early YJs are tough to pass emissions as gassers BUT if you convert them to diesel they fit in a different category (light duty diesel trucks) and will now pass. There is a website out there called Jeeps2diesel that has some info on the swap. Most of the guys used Volvo or Mercedes engines, I think. Japanese engines might turn backwards so watch out for those (You'd need the rest of the driveline). The Japanese engines are good, though, and I think they are worth looking into. In the Philippines they use the Isuzu 4BA1 engine in many of their Jeepneys. These are well built engines and stand up to constant use and abuse all day (and that's after they've been used in a truck for years - they are all used when they go into the Jeepneys). I had considered the 4BA1 for a swap in an M37 (but never did it - yet). Now the 4BT is readily available in junk yards - they used to be really hard to find. So, I'll probably drop a 4BT into the M37 some day. Best of luck - John

 

[jps4jeep]

Yes and No.. In regards to ma.. because I know absolutely nothing about california and because your probably next door to me, light duty diesels were allowed in mass and sold as such, they were not, Prior to 2008 sold in a "light duty car" application. you could purchse a light duty truck in the diesel configuration. The liberty is the most recent example I can think of.

I recall back in the 80's I had a relative that purchased a VW rabbit pickup and it had a diesel, because it qualified as a light duty truck, it was available for purchase in mass. In that time, you could still register a new diesel car in ma, and there were stipulations for the inspection of emissions regarding them, but it had to be purchased in an ajoining state like NH.

I could be wrong, I am not a diesel owner... YET but I do know for a definate fact that we purchased the VW in ma from a ma dealer.

 

[Crazy4diesels]

Hi Johnny,

Yeah, the time frame you could buy diesels in MA was roughly this way, I think (going from my failing memory so things might be a little off)...

Up to the early 90's you could buy light duty diesel trucks (less than 3/4 ton) and diesel cars. You could buy medium and heavy diesel trucks without catalytic converters.

Around 94 light duty trucks were banned (not exectly sure about the date) - the last ones I recall were Blazers (24 MPG). Also Catalytic converters came out on medium duty trucks in early year 94. You could still get diesel cars without computer control.

Diesel cars were available up to 2004 or so with computer control required starting in 96. They were then banned in the 5 communist states (MA, CA, NY, and I don't remember the rest).

A couple of years ago (the 2008 model year) light duty diesel trucks and cars were again available in MA as long as they had a highly complex and expensive pollution control system which used special fuel (ultra low sulpher), particulate traps, special catalysts, urea injection, and/or even more crazy things. They're not all the same but they're all expensive and complex. So we can now buy a Jetta TDI in MA again.

Yeah, those VW Rabbit pickups sure were great - they got like 45-50 MPG and lasted for 300,000 miles. My wife has a 2001 VW Jetta TDI (diesel) which gets 48 MPG. We were so bummed when we heard they had been banned. Once you get the diesel fever you can't be cured. You just gotta hear that sound... Best of luck - John