Engine Replacement or Rebuild?

pdXDisco97

Well-known member
Dec 6, 2011
277
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Oregon
Pretty sure it's time to do some major work on my XD's engine. I'm hearing a low-end knock. I've got approx 150k on the engine, and am prepping for a trip in a few years to Alaska, so I want it to be in the best condition possible. I'm ready to shut it down for a year or two if needed. I plan to take it in to a local shop soon for some testing and diagnosis on the sound, but am starting to consider the different options. I'd love to get opinions about how to approach this.

Option 1; rebuild the current engine. I like that it stays original, but gives it new life, and hopefully a little more power on the hills.

Option 2; replace with 300tdi. Cost?
Option 3; Find a better D1 V8 and swap it.
Option 4; LS swap. Not my favorite, but kind of compelling.
Thoughts?
 

Lake_Bueller

Well-known member
Aug 11, 2004
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Beloit, WI
If cost isn't a concern, the LS conversion is an interesting thought. I was contemplating doing the same with my G4. But in the end, I stumbled upon a totaled truck with a freshly rebuilt motor. After selling off most of the good parts and the rest for scrap metal, I was about net even on the expenses.

If your going to do a rebuild, I'd consider doing a top-hat build on the block. Google Turner Engineering for the parts. Good people. I have a complete 4.6 rebuild kit in my garage. It was supposed to be for the G4. I'm hanging on to it for the next time the engine blows a liner.
 
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rovercanus

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Apr 24, 2004
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I rebuilt the motor in my D2 and just pinned the liners. Do you have a decent machine shop available?
Having someone that can clean your parts really helps and they can check your cross hatching in the cylinder bores and check your crank for wear.
These motors are pretty simple once you get them out.
 
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Tugela

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May 21, 2007
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Seattle
If you can find a used V8 that would probably be the simplest, cheapest, and most original (as in "close to factory", not as in "creative") solution. If you let Will Tillery and Overland Rovers know what you're looking for, they can keep an eye out for engines that would meet your needs since they get a lot of vehicles through their doors. If you're not in a rush, your patience could yield a nice low mileage donor.

My preference would be for a 300TDI conversion. I didn't buy my Rovers for their performance and I'm happy to trade V8 power for the economy, longevity, and characteristics of a TDI. I have driven Rover diesels a lot during my time in Africa and have come to appreciate how good of a match they are for the kind of driving I like to do (slow). Although I cringe to think about ascending long, high mountain passes in the American west with a laden truck "powered" by a 300TDI. You can improve their performance a bit through uprated intercoolers and turbos, but you're never going to get close to the V8. If you want more power on the hills, this is not going to achieve that result.

There are at least two shops in the PNW that specialize in TDI conversions. My first pick would be Lamorna Garage in Seattle, as the owner has been doing TDI swaps for a long time and sources rebuilt crate engines from Turner. Last time I asked, the number he gave me was $15,000 all inclusive. That may sound steep, but I think it's a good value. Lamorna does superb work and they install quality parts. Their TDI swaps are meant to last. There is also a place down by Portland - Zombie Motors, I believe - that does swaps for less but I think they install used engines.
 
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jastutte

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Nov 10, 2009
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if you go with a rebuilt V8 look into an upgraded cam. Crower makes a couple that give some decent benefits.
 

p m

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How are you sure it's bottom-end knock?
I fell for this twice - one time it was broken substrate in the catalytic converters, another - broken power steering pump. In both cases I could bet a Ben Franklin it was bottom end knock.
Before you tear the engine out, pull the pan, unbolt the rod bearing caps, and measure the journals.
In a 250kmi D1 I found that all journals were less than 0.010 under, so I replaced the bearing shells and put everything back together.
It has been 36kmi ago.
 

ERover82

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Nov 26, 2011
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Darien Gap
If you need to go the engine swap route, the easiest and cheapest is just to get a good used stock engine. The next is to go used and rebuild while you use your existing motor (minimal downtime). If you really want to try something else, Robert Davis is working on a GM straight six swap kit for Defenders that might work in a D1 with minimal effort. The GM sixes are cheap, compact, plentiful, more efficient, easy to source parts, and deliver power comparable with the Rover V8 which wont wreck your drivetrain. I'd consider that way before an LS swap.
 
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pdXDisco97

Well-known member
Dec 6, 2011
277
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Oregon
How are you sure it's bottom-end knock?
I fell for this twice - one time it was broken substrate in the catalytic converters, another - broken power steering pump. In both cases I could bet a Ben Franklin it was bottom end knock.
Before you tear the engine out, pull the pan, unbolt the rod bearing caps, and measure the journals.
In a 250kmi D1 I found that all journals were less than 0.010 under, so I replaced the bearing shells and put everything back together.
It has been 36kmi ago.
I've had several responses from another posting also identifying the cats as a possible issue. My muffler is rusted out, so I might just replace the exhaust system completely and see if there's any change there first.
 
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Swedjen2

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Sep 12, 2018
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California
If you hold out hope D1's will become some sort of collector's item (breath-holding not recommended), then rebuild your original engine, but use a Top-Hat block and maybe a hotter cam. If you want V-8 power, I'd send your rig to the guy in Ohio, or get the LS kit.

Check this one out that WAS for sale on Bring-A-Trailer: https://bringatrailer.com/listing/1994-land-rover-discovery/
If you get it done right, looks pretty good.

Speaking of cams, is anyone running a cam from the Wedgeshop? It was recommended by the guy at D & D.
 

ERover82

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Nov 26, 2011
3,899
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Darien Gap
If you hold out hope D1's will become some sort of collector's item (breath-holding not recommended), then rebuild your original engine, but use a Top-Hat block and maybe a hotter cam. If you want V-8 power, I'd send your rig to the guy in Ohio, or get the LS kit.

Check this one out that WAS for sale on Bring-A-Trailer: https://bringatrailer.com/listing/1994-land-rover-discovery/
If you get it done right, looks pretty good.

Speaking of cams, is anyone running a cam from the Wedgeshop? It was recommended by the guy at D & D.

That R380 is not, nor the rest of the driveline, engineered or able to reliably deliver LS power. It's very expensive to do it right, and that's not it.
 
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Swedjen2

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Sep 12, 2018
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California
Regarding the R380 only, we don"t know what suffix R380 is in that '94. Early versions will be hard pressed, but IF it's a suffix K/L, it's rated at 325 ft/lbs torque which equals the max torque of the GM 5.3 LM7.

I would think they would upgrade the diffs to the 4 pin type and axles to 24 spline HD, but no info on those issues.
 

luckyjoe

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Oct 10, 2004
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New Jersey USA
I'll break from the herd and say run from the 200/300 Tdi. I just don't get the appeal for a heavy vehicle (and I have been driving my VW TDI wagon since 2003). In the land of cheap fuel, stick with the V8 and ZF, even in you need rebuild/replace/upgrade them (but hopefully it's just your CAT's).
 
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pdXDisco97

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Dec 6, 2011
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Oregon
I'll break from the herd and say run from the 200/300 Tdi. I just don't get the appeal for a heavy vehicle (and I have been driving my VW TDI wagon since 2003). In the land of cheap fuel, stick with the V8 and ZF, even in you need rebuild/replace/upgrade them (but hopefully it's just your CAT's).
The more I think about it, that's the option I like best. I'm hoping it's something else (not that the engine couldn't use a refresh) like the cats, but I want to be planning ahead for worse case. I think I'd like to keep the XD original, and maybe someday find a 300tdi Disco to play with.
 

Knightspirit

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Sep 22, 2019
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Mount Shasta, CA
I saw an interesting thread on Cummins 2.8 crate motor swap:


Might be a little better than a 200/300 TDI in terms of coming complete as a new motor with everything you need including wiring harness and ECU, and easy parts sourcing...
 
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p m

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The more I think about it, that's the option I like best. I'm hoping it's something else (not that the engine couldn't use a refresh) like the cats, but I want to be planning ahead for worse case. I think I'd like to keep the XD original, and maybe someday find a 300tdi Disco to play with.
Are you talking about 300TDi?
A 300TDi with manual transmission will likely double your driving range on a tank of fuel.
But... It makes less than 3/4 of power of a 3.9/4.0, and contrary to what rumors make you believe, its peak torque is about what a 3.9 puts out barely off idle.