Disco 4 Turbo Diesel V8

[BernHard]

Hi All

https://www.aulro.com/afvb/attachment.php?attachmentid=175823&d=1640230355

You probably already seen the missus post our project up on FB or Insta already, but I thought I would make a thread on here for a more targeted discussion.
Below is all the info you need to know on the project to get caught up;

Discovery 4 Turbo Diesel V8 Conversion

Conversion Included


3.6L Turbo Diesel V8 (Ford Lion, designed for a Range Rover Sport L320)
6 Speed Gearbox for above engine
Active Roll Control Swaybars
Full set of Range Rover Sport ECUs (shows a RRS on startup)


Outstanding Work (any help welcomed)

Bootlid open fault - RRS bootlid sensors installed and vehicle computer confirms bootlid closed... but still tells me its open when closed!
Rear Aircon Not Configured - This one is pretty obvious, L320 doesnt have a rear AC, so no option on configuration editing tools to even include or add it.


Accessories Currently Fitted

110L Brown & Davis Extended Tank
Full length stainless steel 'straight-pipe' exhaust (surprisingly quiet for no resonators or mufflers, but a great note!)
Front and Rear electric diff locks
EGR Deletes
TuffAnt 18" alloy rims, with 265/65 Nitto Ridge Grapplers
Clearview Mirrors (Yes I know you all hate them, but we need them to tow our house!)
Raised Towhitch (First mod I did was **** off the plow!)
Custom Badges
Bumper sticker that only LR nuts will get ;)


Accessories either in progress or in postage

Custom engine & gearbox tune (targeting 250Kw with 760Nm)
Terrafirma discrete winch mount with Sherpa 16,000Lb Steed winch
Full set of underbody protection
Custom paint job from door handles down in black Raptor protective coating
Rijidij Rear spare mount
Full length ARB roof rack with 4x spotlights
ARB Air compressor mounted under chassis
Watermist injection system, and intercooler spray system


Works Completed By

Mechanical installations - Silver Lining Automotive and Myself
Electrical Installations - Silver Lining Automotive
Custom Exhaust - Tonys Mufflers (Sydney)
Configuration & Coding - Silver Lining Automotive & Old Jaguar (Sydney)


Total Outlay So Far
~$50,000 (Not including hidden costs)

Why Did We Do It?

Why not? Haha!
Real story though, it seemed like the most practical option on paper to begin with, but ended up being more costly (both time and money) than anything else we considered. Long story short, unless you have a spare $100k to burn, and another daily driver to keep you going for a year, don't even think about it!

We came from Land Cruiser territory, so once we got a taste of a family 4x4 that wasn't a glorified farm tractor, we were hooked on a disco 4. I sold my weekender E39 M5 (also my dream car) to get one. We bought it 2 years ago with 80,000km on the clock for $32k, and for our big adventurous family, it was perfect. We absolutely loved our disco, so when it snapped a crank in Feb 2021, it was absolutely devastating!

With no second car, we were forced to borrow the mother-in-laws hatchback to get around. But with 4 kids... we wouldn't be able to travel as a family until we get another family car. We were in for a lockdown longer than the government were willing to impose on us, and it would drive us almost to insanity.

I had to start talking options with my mechanic.

Option 1 - V6 replacement... Our engine was welded solid, so there was almost nothing salvageable. Cost would be upward of $30k, and the result would be a 2nd hand V6 that may or may not snap another crank...

Option 2 - Buy another disco 4... This option SHOULD have been the most viable. Considering we got a D4 for $32k with 80,000km 2 years ago, another D4 with 120,000km (the mileage we had when we snapped crank) should be well under $30,000 by now when accounting for depreciation... We buy a replacement D4 for ~$28k, then part off our bricked one for ~$10k... Leaving us only about $18k out of pocket and back on the road in a few weeks... But this was post covid times... there was not a D4 on the market close to replacing our one for any less than $55k... At this point, I was contemplating taking one off Land Rover at gunpoint... we all know they deserve it for this KNOWN design fault.

Option 3 - Convert it to another engine. We considered the petrol V8, but why not do a diesel V8 if we are converting the engine anyway? On paper it looked to be no more expensive than a V6 replacement. This is because the 3.6L TDV8's don't seem to blow up like the TDV6's do. So wreckers find the V8s harder to sell, and henceforth they are cheaper. It was estimated to only take about a month or so for the project to be done, only because there was a lot of unknowns about the conversion that was expected to take a few weeks longer than a standard engine replacement.

So that was our rationalization for our decision. It definitely didn't go as expected, even when factoring in unknown issues. But I will post about that later when I have time.

Stay tuned for part 2!!

[RANDLOVER]

Sounds like a great job, the only thing similar I've seen, is one that featured in one of the Land Rover monthly magazines, either LROwners or LRMonthly I forget which.

[Eric SDV6SE]

Wow, I have often wondered about that conversion because the engine is just awesome, but the rrs body is not one I like. Almost makes me wanna toast the 3.0l on purpose to justify the conversion. Watching with very keen interest.

[Tombie]

Followed the FB posts with interest... Nice work!

[chuck]

Brad

Great write up.

Could you elaborate a bit more about electric diff locks.

[BernHard]

Brad

Great write up.

Could you elaborate a bit more about electric diff locks.

Sure!

In its past life, my Disco only had the front locker installed, which I think is standard. The rear locker was an optional extra on the D4, and its quite rare to find one with it.

While we had the body off doing the conversion, I had a genuine rear locker installed. And while we were uploading the new config for the V8, I had it programmed in too.

Now when I go into 4x4 mode, the beast will turn both front and rear lockers on and off as it needs. Where before it would only use the front locker to pull the car out of a bog, it now uses both lockers to crawl through it like its not even there. 😁

You wont be able to tell if your disco has a rear locker by looking at the info screen, because even if it doesnt have one, it still shows a rear locker icon unlocked. You can look under at the diff to see if it has a black motor hanging out the side, but the easiest way is to turn the ignition on without cranking the engine, and you will hear a buzz and a click under the car. Thats the locks doing a duty cycle. If you hear the same noise under the front, and another down back, you got the optional rear locker!

[loanrangie]

Sure!

In its past life, my Disco only had the front locker installed, which I think is standard. The rear locker was an optional extra on the D4, and its quite rare to find one with it.

While we had the body off doing the conversion, I had a genuine rear locker installed. And while we were uploading the new config for the V8, I had it programmed in too.

Now when I go into 4x4 mode, the beast will turn both front and rear lockers on and off as it needs. Where before it would only use the front locker to pull the car out of a bog, it now uses both lockers to crawl through it like its not even there. 😁

You wont be able to tell if your disco has a rear locker by looking at the info screen, because even if it doesnt have one, it still shows a rear locker icon unlocked. You can look under at the diff to see if it has a black motor hanging out the side, but the easiest way is to turn the ignition on without cranking the engine, and you will hear a buzz and a click under the car. Thats the locks doing a duty cycle. If you hear the same noise under the front, and another down back, you got the optional rear locker!


No disco or RRS came with or had a front locker as an option so you might want to check that, infact i dont think any Landrover ever built had a front locker as an option or factory fitted.

[101RRS]

So been through all the issues of installing a TDV8 but does not know about no OEM diff lock being fitted to the D4 - if that research is lacking what else is lacking. Just put ARB airlockers in front and rear, though need to change the rear D4 diff to a D3 diff to do it.

Followed Disco Mickey's TDV8 installation on the RRS UK forum - now that was a nice piece of work,

[chuck]

Bernard

Thanks for the response - thought you may have come across a locker that can be retrofitted to a D5.

Hopefully Rhino will do a winch bumper next year and that will be my locker!!

Cheers

[BernHard]

Bernard

Thanks for the response - thought you may have come across a locker that can be retrofitted to a D5.

Hopefully Rhino will do a winch bumper next year and that will be my locker!!

Cheers

Haha, yes a winch is certainly a good substitute for a locker, but if you are ever trying to steal dino dna from Jurassic park and crash in a bog, use the locker instead. 😂

And when I say "lockers" i meant the stock E-diffs. Sorry for the confusion. The reason why is because the "common" definition of a lock is to achieve torque equilibrium through a sliding collet with teeth. But an engineers definition of a lock is to achieve torque equilibrium... whether through sliding collets, or clutch plates, the method doesn't matter. If torque equilibrium is achieved, the diff is locked. And it is therefore, a diff... locking... device... built for the purpose of locking a diff... and therefore is, by definition of its very name, a diff locker.

The reason why there is a community divided between people who say e-diffs lock and people who dont is because e-diffs were originally designed to be used in sports cars and road based awd's. So for the greater part of the e-diffs life, they were designed to increase torque within the diff, but were never designed to achieve torque equilibrium (or a lock). So 4x4 nuts hated it when engineers started using sports car tech for an offroad purpose. Especially after they just paid an arm and a leg to get comparable farm machinery installed. 😅

But... if you beef up the clutch plates, and increase the mechanical load on the motor, you can achieve torque equilibrium just like the clutch in a manual does. This is what all land rover e-diffs do when in offroad mode. When the equilibrium is achieve, the diff is locked, and the symbol on the screen showing a lock is lit up.

So yea, it achieves lock, by using clutch plates instead of a sliding collet. And the best thing about using clutch plates over a "typical" aftermarket locker is that you don't break stuff! The clutch in the e-diff will slip before you snap a CV, and it means absolutely nothing to the mechanics of the thing because they are designed to slip when on road. Just pick a better line and try again. But a collet locker won't slip if you approach the rated sheer torque of your cv shafts. It will just snap them clean and ruin your day.

So if you are thinking about replacing your e-diffs with an aftermarket sliding collet locker that was originally designed for farm tractors, DON'T! Your car already mechanically achieves the same thing, and is far more capable and reliable with the e-diff (haha! That statement will ruffle some feathers! 🤣🤣) But if you don't have one in the back, its a relatively easy install because they come as an option, and your computer is already programmed to use it.

Anyway, im sure ill cop **** for this reply. Not even 24 hours on this forum and some other bloke is already flinging **** at me for not knowing as much as he does about my profession. Just reminds me why Im an intorvert and never did forums. 😅

[RANDLOVER]

Haha, yes a winch is certainly a good substitute for a locker, but if you are ever trying to steal dino dna from Jurassic park and crash in a bog, use the locker instead. 😂

And when I say "lockers" i meant the stock E-diffs. Sorry for the confusion................... 😅

That explains it when you say front locker you mean the centre diff and not actually one on the steering axle, and you are right the e-diffs are not just on-off lockers, they are variable lockers and can lock up to what ever degree the traction control deems necessary and can do trick stuff like torque vectoring on road. I found the mag I mentioned earlier, it is LROwner Intl February Issue 2 2021, the conversion was done by Mike Park owner of MMP Land Rover from Dundee Scotland.

[OldGuy]

It has been on my curiosity list also, just in case I had a worst case scenario. How did you go fitting the V8 into the V6 hole.. Does anyone have any thoughts on whether or not the D4 8 speed box could be bolted up?

[Arapiles]

Sure!

In its past life, my Disco only had the front locker installed, which I think is standard. The rear locker was an optional extra on the D4, and its quite rare to find one with it.

While we had the body off doing the conversion, I had a genuine rear locker installed. And while we were uploading the new config for the V8, I had it programmed in too.


Was fitting the rear e-diff difficult? I'd asked about that in the past but the view seemed to be that it was too much trouble to do.

Edit: and a D4 with 80,000ks for $32k seems like a very good price.

[loanrangie]

Haha, yes a winch is certainly a good substitute for a locker, but if you are ever trying to steal dino dna from Jurassic park and crash in a bog, use the locker instead. [emoji23]

And when I say "lockers" i meant the stock E-diffs. Sorry for the confusion. The reason why is because the "common" definition of a lock is to achieve torque equilibrium through a sliding collet with teeth. But an engineers definition of a lock is to achieve torque equilibrium... whether through sliding collets, or clutch plates, the method doesn't matter. If torque equilibrium is achieved, the diff is locked. And it is therefore, a diff... locking... device... built for the purpose of locking a diff... and therefore is, by definition of its very name, a diff locker.

The reason why there is a community divided between people who say e-diffs lock and people who dont is because e-diffs were originally designed to be used in sports cars and road based awd's. So for the greater part of the e-diffs life, they were designed to increase torque within the diff, but were never designed to achieve torque equilibrium (or a lock). So 4x4 nuts hated it when engineers started using sports car tech for an offroad purpose. Especially after they just paid an arm and a leg to get comparable farm machinery installed. [emoji28]

But... if you beef up the clutch plates, and increase the mechanical load on the motor, you can achieve torque equilibrium just like the clutch in a manual does. This is what all land rover e-diffs do when in offroad mode. When the equilibrium is achieve, the diff is locked, and the symbol on the screen showing a lock is lit up.

So yea, it achieves lock, by using clutch plates instead of a sliding collet. And the best thing about using clutch plates over a "typical" aftermarket locker is that you don't break stuff! The clutch in the e-diff will slip before you snap a CV, and it means absolutely nothing to the mechanics of the thing because they are designed to slip when on road. Just pick a better line and try again. But a collet locker won't slip if you approach the rated sheer torque of your cv shafts. It will just snap them clean and ruin your day.

So if you are thinking about replacing your e-diffs with an aftermarket sliding collet locker that was originally designed for farm tractors, DON'T! Your car already mechanically achieves the same thing, and is far more capable and reliable with the e-diff (haha! That statement will ruffle some feathers! [emoji1787][emoji1787]) But if you don't have one in the back, its a relatively easy install because they come as an option, and your computer is already programmed to use it.

Anyway, im sure ill cop **** for this reply. Not even 24 hours on this forum and some other bloke is already flinging **** at me for not knowing as much as he does about my profession. Just reminds me why Im an intorvert and never did forums. [emoji28]Regardless of how it's achieved there is no nor ever been a front locker in a Landover product, the fron diff is open and has no clutches. Nice job of the conversion, was that 50k all up or on top of the vehicle cost ?
I'd just go an L322 TDV8 and save the hassle.

[josh.huber]

Regardless of how it's achieved there is no nor ever been a front locker in a Landover product, the fron diff is open and has no clutches. Nice job of the conversion, was that 50k all up or on top of the vehicle cost ?
I'd just go an L322 TDV8 and save the hassle.

I looked at trading my D4 on one end went away from it. In my opinion the RR just don't have the look of the D4, the accessories or the space. This conversion is awesome for someone like me who is space poor.

Bern... Did you have to put the RR ECUs in, or did you choose too? Im just thinking about the extra cost and work. personally I'd rather it be a D4 with two extra cylinders, is that possible??

Good on ya for stretching the imagination and having a go. You'll be rewarded with a great rig that's for sure!

[350RRC]

I looked at trading my D4 on one end went away from it. In my opinion the RR just don't have the look of the D4, the accessories or the space. This conversion is awesome for someone like me who is space poor.

Bern... Did you have to put the RR ECUs in, or did you choose too? Im just thinking about the extra cost and work. personally I'd rather it be a D4 with two extra cylinders, is that possible??

Good on ya for stretching the imagination and having a go. You'll be rewarded with a great rig that's for sure!

Totally agree with thinking outside the cube.

Years ago 'traditionalists' in the RRC world would say that fitting a 350 would upset the balance of the car and all sorts of other BS.

My response was that I bought it with the 350 already in it and there is no way I would retrofit a 3.5 Rover donk to 'improve' things.

Same sort of logic applies here......... if a D4 came with that V8 would you be pulling it out to put a 2.7 or 3.0 in?

DL

[loanrangie]

I looked at trading my D4 on one end went away from it. In my opinion the RR just don't have the look of the D4, the accessories or the space. This conversion is awesome for someone like me who is space poor.

Bern... Did you have to put the RR ECUs in, or did you choose too? Im just thinking about the extra cost and work. personally I'd rather it be a D4 with two extra cylinders, is that possible??

Good on ya for stretching the imagination and having a go. You'll be rewarded with a great rig that's for sure!True but some AT tyres and a discrete winch and it would be the ultimate tourer come tow vehicle, can get them fairly cheap and a lot less than a converted D4 unless you can do the lot yourself.

[josh.huber]

True but some AT tyres and a discrete winch and it would be the ultimate tourer come tow vehicle, can get them fairly cheap and a lot less than a converted D4 unless you can do the lot yourself.

I don't want a 2.7 or 3.0l . I was only looking due to the crank issue.
The only 3.6l I like is the face lift 2010 I think?! When it comes to towing I like the longer wheel base of the D4, just me. Plus the space issue.. My mate has an rrs we put my fridge and a few items in it. Chockers! I see this as a great mix of reliability and capability. Exciting times to come..

I wouldn't do it as an upgrade.. Im the same as the OP. I'd do it as a repair.

But loan, I take your point. They are very capable. I've seen green oval do a great job with a winch inside the car. Not even bolted.. That's confidence

[Eric SDV6SE]

I wouldn't do it as an upgrade.. Im the same as the OP. I'd do it as a repair.

Same here.

[OldGuy]

Same here.


X2

[Arapiles]

I wouldn't do it as an upgrade.. Im the same as the OP. I'd do it as a repair.



And there have been a few D4s around with blown motors (mostly 2.7s), so if it's within $10k of fitting a new 2.7 why not?

[loanrangie]

And there have been a few D4s around with blown motors (mostly 2.7s), so if it's within $10k of fitting a new 2.7 why not?

It wouldn't be, a territory motor can be bought for 2.5k or less, TDV8 will be 10k alone plus the auto, ecu and associated wiring.
Replacing a 2.7 is fairly cheap these days, the 3.0 doesn't have that luxury since the only donors are D4's and RRS.

[TopEndThom]

And there have been a few D4s around with blown motors (mostly 2.7s), so if it's within $10k of fitting a new 2.7 why not?

Really? Aren’t the D4 2.7 known to be more reliable than the 3.0? And supposedly carry hidden improvements on the 2.7 that went into even the last D3.

[mowog]

I have been following this on facebook. I own a 2010 D4 3.0L which currently has 250000klm on it serviced every 6 months and still going strong. I also have a 2008 L322 3.6 TDV8 I got this a year ago with 97000 klm on it. I love the 3.6 TDV8 the problem with the L322 in this config is the terrible 490 kg payload. I have towed my 3.5t caravan with the L322 and it is a far better tow vehicle than the D4. The biggest issue towing with the L322 is keeping the speed down.

I was considering a TDV8 conversion to my D4 however I have decided to sell both the D4 and the L322 and buy a Defender 110 SE D300.

[Arapiles]

Really? Aren’t the D4 2.7 known to be more reliable than the 3.0? And supposedly carry hidden improvements on the 2.7 that went into even the last D3.

I understood that it was the 2.7 that has the issue with crankshaft failure -there's a recent thread specifically on that topic.

[101RRS]

I understood that it was the 2.7 that has the issue with crankshaft failure -there's a recent thread specifically on that topic.

Yes in the D3 but not the D4 or the Territory - you said it was the 2.7 in the D4 and that is not correct. Even in the D3, 2.7 crank failure was pretty rare.

[Stuart02]

True but some AT tyres and a discrete winch and it would be the ultimate tourer come tow vehicle, can get them fairly cheap and a lot less than a converted D4 unless you can do the lot yourself.

500 kg payload v. 860 kg in the D4. I know which I'd prefer!

Bern, the TDV8 RRS has heavier duty front lower control arms (don't know about the uppers), to handly the extra weight (which will also lower your payload). You might want to check that out for robustness and longevity...

I was crawling some hills around Dargo last week in our D4 3.0, and missing the remapped TDV8 RRS badly. The torque in that thing was outrageous for climbing and towing. You'll have so much fun!

[loanrangie]

500 kg payload v. 860 kg in the D4. I know which I'd prefer!

Bern, the TDV8 RRS has heavier duty front lower control arms (don't know about the uppers), to handly the extra weight (which will also lower your payload). You might want to check that out for robustness and longevity...

I was crawling some hills around Dargo last week in our D4 3.0, and missing the remapped TDV8 RRS badly. The torque in that thing was outrageous for climbing and towing. You'll have so much fun!

Yeah it was more of a cost comparison.

[Jjb3010]

Was fitting the rear e-diff difficult? I'd asked about that in the past but the view seemed to be that it was too much trouble to do.

Edit: and a D4 with 80,000ks for $32k seems like a very good price.

I got one for 7600 with 95,000 but needs a new engine still debating what I do