3.0L High speed Diesel in a WDX?

[Jason Mills]

1)I just bumped up agains the idea of putting A 5 Cyl Mercedes diesel into my WDX....

2)The strong points are, It has about the same amount of power and a bit more Torque of the flat head.

3)It is about the same size, may be a little taller, and wider, yet only about an inch longer.

4)It will Run to 4900 RPM.

Now for the issues:

1)The stock clutch is 8.5 inches, so may be that is not big enough.

2, 3, and 4) this would be my first attempt at an engine swap, thus:

How to align up the crankshaft centerline with the transmission's centerline. (using the original Dodge bellhousing) will require an adaptor plate.

Would 3/4 inch steel be acceptable?

Where to learn more, so that I can anticipate the challanges, rather than be blindsided by them?

Thanks,
Jason

[mcinfantry]

google for searching.

i think which tranny to use is going to be the major pita of the swap

[Charles Talbert]

Better off

Have done many retrofits. If you choose an engine/trans. combo that can be accomplished without the use of an adapter plate, you are ahead of the game from square 1. Adapter plates are expensive & can be a challenge to get exactly correct. An 8.5" clutch is too small for a vehicle of this gross weight, can a large enough clutch be fitted on the flywheel? Peak torque range/RPM of the engine needs to coincide with the gearing of the rest of the drive train, getting out of sink here can make or break a good job in the end. You need to know at what RPM the torque will reach its peak, it should be a little above the half way point of the RPM max for everything to coincide at its best. A transmission with an over drive high gear really helps fuel economy as well as general drive train wear, the slower you can turn it & get the needed performance the better. To me performance & fuel economy are great big factors that I look at very close. Smaller high RPM engines sometimes don't work well in heavier vehicles, all these things must be considered as pulling power doesn't come from RPM, but from the correct torque at the right speed range. Being able to hold a lower RPM at cruise speed will have a drastic effect on fuel economy. How the transmission is geared on the lower end is a biggy also, you don't want a gear box so high that you loose good off-roadability. In these trucks, creeping in off road travel is necessary, as is a good speed range for on highway at the top end. I've never studied all this out in relation to the engine you are thinking of using, but from what you have said, it sounds like its design may be intended for relatively light vehicles used 100% on highway. Taking an engine into an environment for which it was not designed can easily be a disaster for the engine itself as well as the rest of the drive train. At any rate, know all the answers to the above questions before you start spending money, the trial & error method can really be costly & frustrating after the fact.

[Jason Mills]

Charles Talbert, Thanks for your imput. All good questions, of which I will set out to find answers to. I believe that the 5 Cyl 617 model diesel which I am toying with was used in some trucks Although I am not positive about that. I believe that they refit unimogs with these engines, across the pond...

It's peak torque is at about 2,400 RPM, Although it's torque rise is less than stellar below about 1800 or so. That may be a mood breaker right there. I dont want to spend all my time down shifting to keep it in the power band........

Off to do some some more studying.

[MoparNorm]

If you drive offroad....

...you want that torque band down at around 0-1500. My Cummins is happiest at 2100 and below, but ideally works at just off idle. The Merc diesels are OK, but heavy for their power output and a tad too high rpm for my useage, but excellent fuel economy.
Charles is right on, don't get a transplant motor without also getting the trans as part of the package, the adapters and flywheel/clutch/transmission search is not worth the trouble, just ask Paul in NY about how many NV4500 girations he went through before figuring it all out.
MN

[mcinfantry]

cabell garbee knows a few guys that have used cummins 6at's (3600rpm) and are NOT happy with off road performance vs the 4bt.

i say if it aint broke.........
id go cummins 4bt/nv4500

[Jason Mills]

I guess the idea is about dead, As the biggest clutch that would go on a stock flywheel would be limited to about 9 inches...

Thanks for entertaining my armchair delusions.
Jason