Topic: Diesel Conversions

[Jeffy]

A Cummins 4BT may seem a bit underpowered if you leave it stock - but they build up like a 6BT and you can easily make more power than a stock Jeep's driveline can handle. At around 800 lbs, they are a bit hefty on a little Jeep's front end.  Toss in some decent injectors, a bigger turbo, turn up the IP - and you can twist up the axles and shred the differentials like they were made of play doh. 

A GM 6.2/6.5 might be a good candidate - they are lighter than the 4BT and put out gobs of torque.  The engine mounts and the transmission bolt pattern are the same as a SBC, so the swap should not be that difficult.  Army surplus 6.2's are often available and relatively inexpensive.  A J-code 6.2 puts out ~ 150 hp and ~250 lb-ft, that should scoot a Jeep around pretty nicely even without a turbo.  This one would be my choice, but I do have 2 of these engines in my shop.

The venerable Benz 3.0 liter 5 cylinder turbodiesel OM617 is a tough one to beat.  They put out adequate power that can be enhanced to pretty serious levels (Check out some of the YouTube videos of fast diesel Benzes).  There are adapters available to help with the swap.  Fuel economy is good, the engines are well known for their durability and there are a lot of them out there.  I picked up a rusty 300SD just for the engine, the rest of the vehicle will be scrapped and in between I'll part out as much of it as I can.  The net cost of the driveline should be zero.

Save the little VW TDI's for the Suzuki/Geo crowd.  It's a bit small for a Jeep.  They can be turned up, but to make adequate power it will cost.

Sorry if these options aren't available in California - it's gotta suck to live in that state!  At least rust isn't the issue it is up north.  It should be possible to find a nice CJ7 and drop a Benz engine into it of the right vintage...

6BT is a huge engine and too big for most Jeeps.

The GM 6.2L was a decent engine buy really lacked power.  Drive around an 80's Chevy even a K5 and it's slow.

Diesel swaps aren't a big issue with older Jeeps.  Older the better.  There has even been a legal 4BT swap done.  There's a shop in CA that does Merc Diesel swaps in LC's.  It would be a good choice if you can legally do the install.  It's cost prohibited to to a later 90's swap as those Mercs are few and far not to mention expensive.

I wouldn't use a VW TDI for a 39" buggy but for a Expo rig or a light weight crawler on 33's or even 35's it would be fine.

[DieselJeeper]

6BT is a huge engine and too big for most Jeeps.

The GM 6.2L was a decent engine buy really lacked power.  Drive around an 80's Chevy even a K5 and it's slow.

Diesel swaps aren't a big issue with older Jeeps.  Older the better.  There has even been a legal 4BT swap done.  There's a shop in CA that does Merc Diesel swaps in LC's.  It would be a good choice if you can legally do the install.  It's cost prohibited to to a later 90's swap as those Mercs are few and far not to mention expensive.

I wouldn't use a VW TDI for a 39" buggy but for a Expo rig or a light weight crawler on 33's or even 35's it would be fine.

I concur on the 6BT, it's almost 1/2 the weight of a Jeep by itself!  The 4BT can use the same injectors, the IP mods that work on the 6BT all work on the 4BT and the bigger turbo will make it go well enough.  You can build them to an unusable amount of power, it's really overkill for a Jeep.

The 6.2 was good enough for the Humvee, you want a J-code model with a slightly turned up IP.  It'll move a Jeep better than a 4.2 will and give you more torque to do it with.  Toss in the turbo off a 6.5 (or a Banks kit) and you'll have more than enough go power.  But - how can you belittle "slow" on a 4 cylinder Jeep forum?   

The OM617 is a particularly good engine - it's quite economical and is more durable than almost any other engine.  500k miles is common and many of them last much longer.  Usually the rest of the vehicle  wears out before the engine does.  Late Benz diesels had some issues (check out the "Rod Bender") and the computer controls always complicate things.  The OM617 was all mechanical.

[stan98tj]

Lets talk cost of swapping in a diesel. I think i may start looking to do this when i get home in october. Id like to get an idea of all the parts ill need to complete the swap.
lets assume ill go with the 1.9 or the 4bt.
Aside from the engine, ill need a new tranny, transfer case, fuel pump and fuel lines. I dont even know what kind of a tranny would bolt up to the 1.9VW. Would i pull the fuel pump from the VW? what if i want A/C. My jeep doesnt have A/C now, but if i were to do this swap i wouldnt mind having it. Lastly, what about the axles? I will absolutely be getting rid of my d35 when i get home, im keeping the d30. Ill most likely gear to 4.56. With a diesel, i dont think my ratios will work anymore. The d44 will hold up im sure to the torque put out by even a tuned 1.9, but what about the d30?
Any of you think this swap can be done for under $10k ?

[sharpxmen]

talking vw
for a/c: get a motor that has the compressor on it so you don't have to figure out mounts, idler pulleys and serpentine belt. use the rest of the system from TJ salvage parts.

transmission: best bet is to get the AX15/NV3550 adapted to the engine, otherwise would be a challenge to find something that will bolt-on to the 1.9 vw and work in the Jeep. only big problem here is to get the clutch working (you might end up with a frankensteined one to match the diameter of the vw clutch), the adapter plate can be done at a machine shop but i have no idea how extensive the machining will be and how complicated or not the adapter will be - can be done and probably most importan step in the whole process.

you will also need the full harness with the fuel injection computer and accessories/sensors.

d30 will be fine imo, of course a stronger axle will always be a plus

as far as pricing goes that depends mostly on how much you spend on the engine with harness and ECU and how much the adapter will take you, i would think $10k will be enough, can't think of costing more and to be honest it's steep at that price. A rolled over, totalled vw would probably be best if there was no big front impact or the engine didn't suffer a big hit to be more specific (so no broken parts or bent crankshaft).

[stan98tj]

talking vw
for a/c: get a motor that has the compressor on it so you don't have to figure out mounts, idler pulleys and serpentine belt. use the rest of the system from TJ salvage parts.

transmission: best bet is to get the AX15/NV3550 adapted to the engine, otherwise would be a challenge to find something that will bolt-on to the 1.9 vw and work in the Jeep. only big problem here is to get the clutch working (you might end up with a frankensteined one to match the diameter of the vw clutch), the adapter plate can be done at a machine shop but i have no idea how extensive the machining will be and how complicated or not the adapter will be - can be done and probably most importan step in the whole process.

you will also need the full harness with the fuel injection computer and accessories/sensors.

d30 will be fine imo, of course a stronger axle will always be a plus

as far as pricing goes that depends mostly on how much you spend on the engine with harness and ECU and how much the adapter will take you, i would think $10k will be enough, can't think of costing more and to be honest it's steep at that price. A rolled over, totalled vw would probably be best if there was no big front impact or the engine didn't suffer a big hit to be more specific (so no broken parts or bent crankshaft).

this is becoming tempting. i think i might wanna keep it an auto. less modification i would think. id have to find an auto that would hold up.

[stan98tj]

anyone know if theres an auto tranny that would work with the 1.9 VW, or an auto that would work with the 4bt?

[Jeffy]

anyone know if theres an auto tranny that would work with the 1.9 VW, or an auto that would work with the 4bt?

Kinda going to the two extremes with the diesel idea aren't you?  I would suspect you could make an adapter plate if you really wanted to.  As for an off the shelf option, I don't think so.  You'll want to check out Toyota sites and see what they use.

The 4BT on the other hand uses a GM 90* bolt pattern which is why you can bolt a TH400 to it.

[stan98tj]

Kinda going to the two extremes with the diesel idea aren't you? 

ive been into the idea for as long as ive had the jeep. now that it seems financially feasible, im trying to gather all the info i can so that i can appreciate the depth of the project. Id like to keep it an auto if i can (i like wheeling that way, a bit easier for me) but if i have to switch to manual i suppose i would.

[grumpygy]

Just saw this www.dieselbruiser.com   They are doing a conversion to a 4bt in JK's.  Saw this in 4wheel & Off-road.

[stan98tj]

I'm leaning towards a VW TDI swap this summer.

[andpgud]

I'm leaning towards a VW TDI swap this summer.

Any nows on that?
I am thinking the same thing.
Would like to run 33" and some trailer. The VW TDI should handle that, right?
Its the MPG I am seeking .Anyone know where I could read about this how would it be best to tackle?

[RNandKT]

There is actually a company that makes a kit to put the VW TDI 1.9 into a Jeep. It makes about the same HP as our 2.5 stock, but about 50% more torque. And you can increase boost and other things.

Downside is I hear because of the increased stress the Jeep places on the engine you pretty much have to change your timing belt like every 30K miles to prevent it from snapping and destroying valves.

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

Also after the cost of the kit and the VW motor, it would probably just be cheaper to own a TDI jetta to drive around half the time. But certainly not as cool.

[grumpygy]

New Magazine just came out Diesel Swaps.

They list several companies



http://www.anvilandco.com/

http://www.bruiserconversions.com/



This one list conversion kits for jeep 76-2013.

http://jdjeeps.com/