Whatever happened to the MB diesel

[TK064]

conversion that was being done. I lost touch for a while and was looking for an update.

Thanks

[Jason Mills]

I am toying with the idea. Had a 183 Cid turbo diesel sitting in the barn. Now I am going to put that engine back in a car, and the flathead back in the 46yet most seem to think that it is not the best choice... as the flywheel is only a 9 inch unit, and they only put out about 170 lb/ft of torque... but it will turn 4500 rpm all day long, which was what got me thinking about doing it last summer.

[MoparNorm]

Hi Jason,
While a diesel can be a prefered choice for many reasons, such as fuel economy, torque, longevity and the ability to run on alternate fuels, the motor that you mention is not the correct one to use for a truck. Not enough torque and too much rpm to be used effectively. That motor is better suited for a ferd focus.....= ) At 4500 rpm you'd beat you and the truck to death when off-road.
A motor for a motors sake whether too small or too big will leave you cash poor and unhappy with the results.
If you are serious about the diesel, look at the VM 2.8 found in the Jeep Liberty, the Cummins 4bt, the Mercedes 3.0 and others with a weight of less than 700 lbs and a torque output in the 300's and up.
Adapters for a suitable trans and motor mounts wil be you biggest challenge, as well as clearing the front axle, since most small diesels tend to be very deep or tall when compared to the gas motor that was original equipment.
MN

[Jason Mills]

Moparnorm,
I realize that the 617 MB engine is limited in terms of torque rise. Yet it has a agricultural heritage, and a stout bottom end... and most diesels can be set up to produce a bit more torque than they come from the factory with. So I am not activly planning on doing a swap, just dreaming, and thinking "what if", out loud. I appreciate your perspective, and clear headed questions. they are questions that need to be considered, and answered with a delibrate manor.. I will use them to continue dreaming, while installing the 230 back in the truck.
J

[Jason Mills]

If you are serious about the diesel, look at the VM 2.8 found in the Jeep Liberty, the Cummins 4bt, the Mercedes 3.0 and others with a weight of less than 700 lbs and a torque output in the 300's and up.

MN

The 617 is the 3.0 MB 5 cylinder... the 3.0 MB 6 cylinder is a 603, and also what I consider a bit of a top end performer, I doubt it puts out enough torque on the bottom end.. But Isn't the WDX's stock transmission rating limited to about 230 LB/FT of torque? the day dream was to keep the original transmission, actually to try and keep the truck stock from the bell housing back... Yep just keep dreaming, as you can tell I dont have the experence to back up my day dreams.... Do people run into trouble with the axle shafts breaking with 300 lb/ft comming out of the engine room?

[CGarbee]

Well, as somebody who has 300lb-ft... No problem with breaking axles (let me pause to knock on some wood here...) as I just idle over stuff...

One thing that I have noticed talking to folks is that people with big blocks or diesels under the hoods tend to not break stuff as much as folks with small blocks or stock engines... Or at least, that is what it seems like from a very unscientific survey... I think that the folks with the bigger engines or diesels tend to be lighter on the "go pedal" and use the avaiable torque to not shock load the driveline while folks with the smaller engines and stock power have to wind up the engines a bit to get torque and have a greater tendency to shock load (especially when a spinner tire catches) and break things... Just my opinion FWIW.

I do cary a spare set of axles in my under bed toolbox... :)

As with anything, I think a good part of it is how you drive. A good part is the condition of the parts (how much wear (slop) in joints, abuse level in the past, general fatigue)....

[Jason Mills]

understood, you make a good point.. I will take it as unscientific fact..

[MoparNorm]

Nope, I'd take what he says as scientific fact...= )
The stock WDX trans is a NP420, the NP435 has nearly the same bolt pattern (most bells would accept both) and would live behind the 4bt. The 2.8 VM I mentioned earlier is mated to an all aluminum trans and does just fine. Cabell's point and my point is this, low rpm torque is useable torque, high rpm torque is not, at least off road. It's called rock crawling for a reason and the low gear ratios in the PW axles and a super low transfer case make for a perfect combination to conquer obstacles at low speed. It's the low speeds that save wear and tear on components and prevent damage.
I've been driving off road for nearly 50 years and my feeling now is the same as it was in 1958, driver skill, driver skill, driver skill. The driver is 90% of any equasion, I've seen people drive over incredible obstacles with stock vehicles and street tires and I've seen an overbuilt rig with 44" tires and 800 HP destoy itself because the loose nut was behind the wheel. You don't need HP or speed or high rpm's to travel off road, in fact that is probably the single biggest reason that many areas are now closed to our use, a few idiots have ruined it for the majority. Drive "elegantly" and slow and you'll conquer any obstacle and save your vehicle and the environment from damage. Find or design a rig around that premis and you can't go wrong.
MN

[Jason Mills]

I think where we are running into trouble here is with sematics... I don't in any way contest that peak torque is best found below 2000 rpm. Nor do I believe that abusing equipment is fun or exciting or worthy of any form of respect. But I also dont spend much time off road, in fact the amount of time I spend in all wheel drive mode is 10% at best, most if which has been pushing snow, where the shock load on the drive tran is minimal... and torque is still king.... WAY back when(last year), I was just wondering out loud if a mercedes diesel would be a 'bad' idea.. I made some innocent assumptions which have now been brought to light, and corrected... I do not wish to appear or be disrespectful of anyone or the experence they bring to this fourm. Nor do wish to end up with a butchered truck, thus the flat head will be reinstalled at least for a while...
Jason

[MoparNorm]

No disrespect assumed or taken, the problem with many of my posts are that you can't see the smile on my face when I type...unless I do this...= )

I think that Mercedes would be a great engine,...in a Sprinter transport bus...[see me smiling? = ) ]
The scary thing about the Mercedes was the 4500 rpm, especially when I think of cruising at 95 in my Cummins...at 3000....= )
Now they DO have a new 3.0 coming out in a few months, 45 state legal (**** california!) and it puts out real nice HP in the mid 200's and torque numbers in the mid 300's. It gets near 30 mpg and runs real quiet and real clean, it will be available in the Jeep Commander and Grand Cherokee [interesting secret fact, Mercedes has scrapped their SUV programs for the most part and the R-M and ML are now built on Jeep platforms...shhh they don't want the german buyers to know...= )]
MN