So it's been four years, two D1's, and a whole lot of dreaming (and a very patient wife who's probably listened me talk about diesel engines more than some freightliner techs) and we're finally in the home stretch towards owning an oil burning Discovery. And by home stretch I mean I've got an engine and will be installing it at some point "soon".

I feel like I've scoured every corner of the internet trying to gather info on this swap, and I thought I should create a thread to document it as best as I can for anyone who's interested in this sort of thing!


The plan is such:

'98 Disco 1, currently riding on 4" HD springs, I did the head gaskets last year and runs great, but accessories are dying a slow death (been through everything but the a/c compressor this year).

'89 Detroit 6.2L Diesel V8, J-code "Industrial" (same as the military humvees). Dimensionally very similar to the Rover V8. Much heavier (see the HD springs above). HP/revs are a decent match to the LR motor. torque comes in at ~900 rpm and just keeps going. Did I mention it's diesel? Also sips gas, burns anything, and parts are in stock everywhere.

GM bellhousing mated to an easy to machine aluminum adaptor plate, aluminum centering bushings, welded LR to GM "flex plate sandwich". If I can machine these items, YOU CAN TO!

Cutting, measuring, and welding motor mounts is going to be a bit of a pain. Still researching that - I've seen SBC adaptors for land rovers before, If I can get solid measurements making an adaptor would be preferable to fabbing entirely new mounts. Or buy the SBC ones, but they cost more than the engine!

I'll keep posting updates as they happen. For now, here's the donor engine, out of a GMC tow truck with 100k:

 

Sips GAS?
What about transmission?

 

If your talking Humvee I believe that engine is horrible on fuel economy iirc

If you are talking the olds diesel from the ccuv chevy blazer/ pickup then yes decent on fuel pretty sure 2 different engines

 

The diesel engines on our humvees get about 8mpg.

-US Marine-

 

iirc either way they are very heavy engines, you may need to consider more then just HD springs, there are the swivel pins, steering, pan hard bar and bushings to probly take into consideration with this much weight jump

I know guys have done Chevy 350 conversions but think this is heavier, either way very interesting and I am curious how it will work out

 

Haha, sips fuel.
Tranny will remain stock. Looking into a possible torque converter mod, but there ain't much info out there...
The olds diesel and the Detroit diesel are two very different engines, the olds was only around for a few years and was a terrible engine, apparently it actually contributed to the American consumer's distaste for diesel in the 70's. That's how awful it was. The Detroit was built from the get go as an economical alternative to the 350. All ccuv's, blazers, basically anything GM diesel from early 80's to late 90's was the Detroit diesel I'm using.
Humvees also weigh a ton more and use a 3 speed tranny. Frmr. CA Guard.
There are a bunch of discos and rrc's in the wild sporting this engine, some with fancy driveline swaps and some with stock zf tranny. In fact, a D1 just went up on craigslist in my area with almost the exact same specs as I plan for mine. So it's a proven swap, the actual task just isn't very well documented!

 

Here's a D1 with a 6.2: My new-to-me 6.2L Disco - Expedition Portal Here's a guide for swapping one into a Classic: GMC 6.2 Diesel V8 engine conversion in Range Rover Here's one in a Landy overseas: 6.2 power into a Land Rover Discovery - TheDieselPage.com Forums
And here's some info on 6.2 rebuilds: GM 6.2L Buildup - Diesel Power Magazine
I have some experience with these engines. We had one in a 1982 shop truck we used to haul boats with and it was pretty gutless but it did keep running. When I was in graduate school, we acquired one in a 1 1/4 ton Chevy surplus pickup. It came with the glowplug system torn apart. I picked up a controller from a later model along with the appropriate glowplugs and it started awesome. The later model electronic controller is a one-piece unit that senses the initial current when you turn the key then takes it from there, power up the plugs, lighting the dash indicator and then shutting off when the plugs are hot. I would try to integrate that. I don't have the best opinion of these engines, but that is because for their size and weight they don't make much power. But I'm beginning to realize that in a Discovery, they are plenty powerful enough, they fit and they are cheap!

 

I'm also very interested in this swap, I Love my 4.2, but I've always wanted a diesel. I think ill wait till I get enough time to swap a 6.6 D-Max and really open a can of worms.

Are you keeping your stock tranny?
Good luck with the project, Ill be following!!

 

Thanks for those links, I've seen the landyzone one (it was a big help when I was planning this) but the others are going to help a lot too! I agree, they have a so-so reputation in the full-size trucks. Since being designed for economy instead of power they definitely don't compare favorably with the International or Cummins engines. But like you said they're cheap and plentiful (I got mine in great condition with low-ish miles for $200!), parts are easy to find, and are a great match for our lighter trucks!

Also an IH or Cummins would break our stock drivetrain almost immediately and weigh more. Except the 4bt, but those cost more than I paid for my truck!

I think a Dmax would be a huge undertaking, but that sure would be an awesome setup! For the costs associated a 4bt might be a better choice and have less fitment issues.

For this I will keep the stock ZF auto tranny. I've been looking on bmw forums to see if there's a better torque converter I can use. The 4.0 as I understand stalls around 2000 rpm, which is high for the diesel's torque curve. I might have to have a custom one made. Of the rig's I've seen they kept the stock rover converter, so maybe it's a non-issue. Down the line I'd like to install a 700R4 or NV4500, but there's a lot more fab work involved in either of those, and right now I just want to drive it!

In an ideal world I could find a t-case from an early 3speed RRC and use the hi range gear set from that, which I believe is around 1.003 vs the D1 1.211. Ashcroft's calculator puts me in a pretty economical highway rev's with that setup, thus no need to swap transmissions. *ought* to be good for ~ 25mpg...

 

Should be a fun ride when you're done. Hummers got horrible fuel economy because of their weight, box-like aerodynamics, and of course their gear-reduction hubs designed for low speed crawling, not highway travel. I think the DD will be a great match for a Disco. BTW I have a 7.3 IH turbo diesel in my pickup (not a Powerstroke, an older IDI), and the dressed weight of that motor is in excess of 1000 lbs. I'm sure it would be fun to stuff into a LR once one replaced the entire front end. Can't imagine fitting a large enough radiator to handle that much motor, I don't think there's enough surface area on the front of a Disco. But the fuel economy would be impressive: my 6500+ lb. truck gets an average of 17.5 MPG, and even towing over 6k gets 14, just a little worse than our D1 averages. I would think that DD would easily get in the mid to high 20's. Good luck!