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Putting a Disco 200TDi engine in a 90

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As early Disco's are getting very cheap to buy, and the previous TD engines are rather pants, it's now becoming more popular to fit the 200TDi engine in the early 90's. Power output and fuel consuption are greatly improved, plus the added bonus that your truck is worth considerably more.

Some parts of this job are relatively easy, and a few are swines. I wouldn't say this is a DIY job, as welding/fabricating is needed as well as a reasonable ability to use basic tools. The following is how I did the job - there are in a few cases more than one way to do it. Actually putting the engine in the motor is very quick, making what modifications that are needed drags the job right out. Like I said, it is worth it though. If you are able to do the work yourself, then once you have everything you need, allow a week to do it. Things can and will go wrong, it still takes me three days to do this and I've done it a few times now.

If you are going to follow these instructions to the letter, then you will need:-

A complete Discovery 200TDi engine complete with PAS pump, alternator, fuel filter, and fuel pipes intact.

Remove the flywheel and then replace the TDi flywheel housing with the TD one. All the studs will then line up with the bell housing.

Best to replace the crank rear seal while the flywheel is off. It's wise to 'glue' the seal in with stud lock or similar. It has been known for this seal to work it's way out.

TD5 downpipe (about £30)

Service parts, including timing gear and crank oil seals

Borg & Beck clutch kit, plus clutch operating arm.

Clutch slave cylinder (TD type).

While the engine is out, clean it and do any work necessary. It sits right back when fitted in the vehicle, but not particularly difficult to work on.

I understand that the original viscous fan can't be used unless you trim the blades back because they clout the steering box. We had a leccy fan anyway, so I don't know for sure if this is the case.

Anyway, loads of pictures with descriptions. If you're not sure about anything, then ask.

This is what you need to get! complete as much as possible, this makes it so much easier than trying to alter brackets and make up pipework.


Even though the history of the clutch is known, the amount of work involved in replacing it makes the additional cost worthwhile.


Nice new Borg & Beck unit.


The usual gunky mess inside the timing cover.


The usual culprit is the crank seal, although there are a couple of other places that oil can get into the timing case from


Clean it up, replace all the timing gear and both crank oil seals. Do it properly and then forget it for a long while. If the timing belt or one of it's components fails it won't wreck the engine, but it's damned inconvenient.


The engine mountings and chassis rubbers from the TD engine will bolt straight onto the TDi block.


There you go, the easy bit is over. Looks great, but it gets complicated now!


Now the hard bit - the exhaust downpipe. First time it took me about 11 hours to do, now it's down to about 3. The underslung Turbo on the TDi engine means you have little room to work in, but it is possible with a lot of thought and patience. This is where a reasonable skill at welding is needed. You need to remove the short downpipe that's held to the turbo body by three nuts. Also remove the three studs - they are too long and three M10 x 20mm bolts have to be used.

Materials needed are the old TD downpipe and a TD5 downpipe. The flange on the TD5 downpipe is the same hole pattern as the turbo downpipe, and this flange is what the downpip[e is based on.

So, cut the flage off, leaving a 10mm lip to weld to. You need to create a 90dg + bend in a 110mm gap with a pipe that is 65mm O/D. Repeatedly fitting and then removing the work as you go is a pain, but getting it wrong will drive you mad.

Use a 1mm cutting blade in an angle grinder or careful use of a hacksaw.

Initial 'bend'


And again. You need to do several of these to finish the job.


Spot welds first until you're confident the pipe shape is right.


Top bend complete, but still only spot welded. You have little room to fit the pipe, so a lot af patience here.

The full weld won't be done until the pipe is finished and trial fitted.


This is it almost finished. The end has to connect to the rest of the TD system, so I'll use the flared end and flange off the old pipe to do this.


The finished article. I test fitted it, then seam welded and cleaned. Looks good and this is the first one I ever made.


The fabricated downpipe now fitted to the rest of the TD exhaust. Heat sheild is the same and in the same place - no ther mods apart from moving the clutch pipe towards the inner wing.


Things are pretty tight. 10mm on one side and 15mm on the other.


View from the top. I used M10x20mm socket head bolts. Doing two of them up is very fiddly.


Ok, that's the exhaust finished, now the radiator/intercooler.

The TDi Radiator/intercooler frame is a bit too high by 28mm, so it has to be lowered. As there are only really two places that this can be done, I chose what I thought was the easiest, at that was the two locating brackets that are actually on the front crossmember. There are two rubber mounts that sit in the top of these, so I removed the top bit with the hole in, reduced the height of the bracket by 28mm, and then welded the hole back on again. There are also two small lugs either side of the radiator frame that have to be completely removed.


The hole removed.


Cut the bracket down by 28mm. This is where those skinny cutting blades are appreciated.

Then the hole welded back on. Make sure the hole goes back in line with where it was before. Too far forward and the front panel doesn't fit.


You can buy Disco top radiator mountings and make the small effort needed to fit them, or you can alter the TD ones and then keep the bonnet prop bracket as it was before the conversion.

Looks a bit bodged now, bit works ok.


Other side looks a little better.


The radiator fitted, looks good.


The pipework for the cold side of the turbo varies on where you want to put the air filter, what air filter you use, if you have a snorkel, and what side you fit it. Generally the air filter can be made to fit tight into the corner on the passenger side in the corner of the intercooler. The concertina pipe that was on the TD engine is a great help, and two or three of them makes the job a lot easier. The cold side of the turbo is very close to the inner wing. and I recommend cutting away the inner wing to make more room for a 90dg rubber elbow to be used.

Other stuff:-

Wiring is the same and the same colours and will all reach to where it needs to go. The alternator on the TD engine has a lucas plug on it, but the disco one is one 6mm and one 5mm 'eye'. You can buy these and the the correct crimping tool to attach them. The wires to the alternator are too long, so cut them back. Don't forget to thread it along the side of the block, through the clips that are under the glow plugs, then through the gap behind the water pump. Messy wiring and fuel pipes are unnecessary and ruin what is otherwise a good job.

The Disco fuel filter has to be used (one less pipe). Threads are the same etc etc. however, the two that go to the filter are a bit too short by around 100mm, so buy 8mm I/D fuel pipe and 4xjubilee clips of the right size. and lengthen the pipes in a convenient place.

Use the TD oil cooler pipes (the disco ones are too short) However, the two threaded pieces in the radiator are not compatible, so unscrew the ones out of the TD rad and put them in place of the ones that are in the Disco one.

PAS pipes. The low pressure one is ok and can be used as is, but the pressure side is a different story.

Connection to the back of the pump is different, so you need to get the pipe altered by a hydraulics place such as Pirtek. This pipe is also too short and needs to be lengthened by 300mm. The two pipes will then route the way they are supposed to and will fit in the brackets on the rear face of the front crossmember.

Radiator hoses were made from using bits from both engines and with a bit of thought a tidy job can be achieved.

There you go - easy innit :P

Take your time and think before doing anything. The conversion is definitely worth it.


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If you need a motor to look at I have a Disco motor fitted to mine. So can call by for a photo shoot or note making session. I come back to Minehead every couple of weeks so let me know if you need my veh to look at.

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Les excellent thread

I glad I brought mine with the conversion already done ............. mine has the disco down pipe and modified pipework/bulkhead ............... the slave is a pig to get to and work on....... one of the 1st jobs when i brought it also they never bothered to lower the rad so bonnet sits up around half an inch or so ho hum that's landrovers



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Maybe. Works do tonite. Champagne b/fast at 0230 :):) so Sat is going to be a rite off. Sun may actualy get round to going out on the plain. Been here in Tidworth over 3 months and not turned a wheel out there :( . Done a fair bit of tracked milage but nothing else.

The trouble I have is my bloody engine dripping oil everytime I stop. Not the friendliest thing to be doing. If I come down I'll give you a bell on Sat pm if that's OK. Is it a spare seat or veh place?

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  • 1 month later...

By Dan/James


I know there are various other write ups on this forum and others but thought we (DSN and JST) would add our comments and how we did it. The overall impression was that its a lot easier than people make out to fit the disco engine, but we did cheat with the exhaust bit!!!

We were converting a 90 TD to 200 TDi using a disco engine. We were lucky in that we had a garage to work in (no heating though!!) with engine crane, air tools etc easily to hand, this made life more pleasant than it could have been! Unfortunately we had to get the vehicle from Warwick to Taunton to do the job, (that’s where the garage and new to us engine was!) rover and trailer to the rescue then:


Fastest the TD has been in a long time!!! (and furthest without breaking down!!!)

We started the job at 1600 on Tuesday and we had the engine fitted and running by Thursday 1730hrs. (well it ran for 30s before it dumped all the oil as we failed to notice the turbo oil feed wasn’t connected properly!) That included several trips out for spares.

We used the TD alternator, starter, and PAS pump and PAS bracket. This resulted in the PAS being mounted in the same position as a 200 defender lump (ditto the alternator ) Not in the std 200 Tdi Disco location. Brackets were made up from 5mm plate to hold the alternator front and rear.

All locations are described standing in front of the vehicle looking at the engine. Part numbers are from EPC with the associated LR pricing from last year (dealer prices)

In detail:

Belts: 2 drive belts were used. One for the PAS (tensioned on the PAS bracket), Halfords Part no HB800A (length 800mm, ‘A’ being their thinnest belt) and one for the alternator, water pump, and crank. A Std Tdi and TD fan belt. Note on a disco 200tdi the PAS pump would normally have a belt driving the Alternator.



PAS: The standard Defender TD and Defender TDI mounting bracket (ETC8854, £71) and the pumps front, flat, mounting plate (ERR1976 £11) was used to mount the PAS pump at the bottom RHS of the engine. In this position the pump runs off the front 200tdi disco crank pulley. This is the same pulley the water pump is also in line with. To have one belt going from the PAS to the water pump and around the crank we deemed would not provide enough drive due to the limited contact the belt has with the crank pulley. Therefore we decided to move the PAS pump back (using 13mm spacers and longer bolts on the back of the mounting plate) to bring the PAS pulley (single pulley as from TD pump) in line with the rear crankshaft pulley. This was then tensioned off the PAS mounting plate and a Halfords (details above) belt used. The PAS system does not need to be broken into to do any of this, it can just be unbolted and left in the engine bay whilst the old engine is being removed.

Alternator: The alternator needed to run off the front crank pulley, with the same belt also driving the water pump. Tension was achieved off the Alternator mountings. The std TD/Tdi adjusting bracket was used on the front left, attached to a timing cover bolt, with the bottom mounting being made up from 5mm steel plate. The front mounting was a triangular plate, using the front alternator mounting hole and two PAS mounting plate holes. A spacer was also needed at the top for the alt mounting.


The rear mounting was again made from 5mm steel plate with two lugs welded on with bolt holes in them. This was attached to the rear alternator-mounting bracket and the top PAS bracket (not plate!) mount.


Intercooler hosing: We had some old/spare intercooler pipes from 300 defender, 200tdi disco, the old TD blue turbo pipe and defender TD5 pipes lying around. A combination of these made the pipework for the intercooler piping. The schematic below shows the pipe combinations we used with associated part nos.



Fuel connections: The std TD fuel filter and housing was used. The existing fuel feed pipe from the tank to the lift pump fitted. (no extra parts needed) The existing lift pump to filter housing pipe was used with the unions fitting. A new pipe was made up to go from the filter to the front of the fuel injection Pump (FIP) with the older style union at the filter end and new banjo style connector onto the FIP. (about £3 from a local FIP specialist for both connectors). If you can’t get hold of the parts locally the tdi fuel pipe is ESR395 (£6.45) which has the correct Banjo on the FIP end but you will need to replace the union at the filter housing end with one off the old ones. (you will also need a new olive). The old filter housing to rear of the TD FIP was removed and blanked off at the filter housing using blanking plug 517689 (£2.49) and washer 517706 (£0.13) The TD injector leakoff back to the top of the filter housing was removed and blanked off. The Tdi leakoff from the injectors goes to the back of the FIP. From the banjo connector here it goes back to the fuel tank. The std TD fuel return pipe was used with a push fit of the pipe onto the back of the Tdi FIP.


(Note: Shown without the planking plug fitted hence short, blocked off pipe on the LHS rear of housing)

Air filter: Like a lot of the conversion, I had all TD bits but not all Tdi bits. We therefore looked at using the TD air filter assembly.

Due to the intercooler pipes etc, the vertical installation of the TD air filter housing is no longer feasible (well we couldn’t see it was so ditched the idea early on) so we needed a new location. There is lots of space in between radiator and engine as no viscous fan is fitted, but we didn’t want to block the space too much as this would limit air flow around the radiator and onto the engine. An electric fan is still to be fitted so best to keep the space clear.

Having seen the 300tdi method (filter lying down so to speak), we had a look at this idea. In the end, we decided to mount onto the flat area in front of the fuel pump where I think an A/C system would go. This already has some threaded holes so gives a base to work from.

We ended up making a bracket that went onto two of these then clamped onto what was the bottom of the filter. We also left one of the original 3 mounting legs on the bottom of the filter air box. This runs rearwards towards the bulkhead and is then bolted to an upright stay that in turn is bolted to the throttle cable plate. (Only because it was convenient and there!) This was to add strength to the mouting.

The location idea works very well as my drivers side mounted snorkel tubing now runs under the wing then pops through between the PAS bottle and the expansion tank. In line with this is the air intake hole to the filter (side mounted) so it runs straight into filter. We then have the pipe running out the front of the filter, around the front of the engine and down into turbo intake. The setup also minimises the pipe lengths with a driver side mounted snorkel.

The only current issue is the filter is currently not supported well enough. There is too much weight in front of the bracket so the first offroading will no doubt end up with the filter mounting struggling. The plan is to build a support bracket up the front of the timing case and then sit underneath the main filter body with it resting on a rubber mount. This should then support the weight and provide some damping. I will also look to have a strap over the back of the filter again with some rubber to isolate it all. Update to follow.


Exhaust: To save time and many bodges, (and because JST is carp at welding (see pics!!!)) I bought the Steve Parker exhaust system. At £105 +vat and delivery, it is not cheap but considering the time and effort saved, it was worth it I felt. If you are an expert at fabrication and welding etc then you will certainly be able to make it cheaper but I definitely don’t fit into this category!

The system comes in 2 parts and comes with 2 crimping clamps, new manifold seal and new nuts for the studs.


As the studs were knackered on the engine I got, I ended up using bolts to hold it onto the manifold.

I had expected the kit to have a flanged (the triangular bracket with 3 bolts to pull the 2 parts together) end so it would mount to my TD pipe work but it didn’t. It came with a flared end and a lose piece of pipe stuffed into this. Due to the size variation, I found I needed to chop my old much smaller bore exhaust and weld on this short piece. This then mounted into the flared part and was clamped tight.

As there are no instructions with the kit, this was my assumed method so might not be how Steve Parker expects it to be used.

The problem I found was where the join occurs was not where my old pipe was running in a straight line. It was in fact where the pipe is curving over the front of the gearbox cross-member so I struggled to find a suitable alignment and then work out how to cut and weld on the extra bit. If I did it again, I would purchase a longer piece of tube and weld that to the old exhaust further back so a straight run into the main curved down pipe.

You will need to cut the clutch pipe support bracket that is on the bulkhead as this will be too close to the exhaust. There is enough slack to cut it then push it away from the centre line. Note that once you have disconnected the slave cylinder from the bell housing pushing the clutch pedal to take the vehicle out of gear!!! Really buggers things up (JST!!!!!) Its also quite hard to bleed again as the ‘new’ exhaust limits access.


Bulkhead proximity


Radiator mountings: Won’t mention much here as Les Henson’s report covers how he did it and basically we copied this. As it was a 300tdi Disco assembly I had, I chopped the 2 side lugs off the assembly so it fitted into gap. I then chopped off the rubber mounting holes on the chassis cross member then cut approx. 28/30mm off the legs then rewelded the holes back on. We then chopped a bit off the pins on the bottom of the radiator as these were almost resting on the cross member rather than floating in the rubber mounts.

This is exactly how Les did his. (But his welding is/was much better)





The bit we did differently was the top mounts. The tdi mounts seem to work from the front latch plate rather than side mounted plates like the TD. We decided to mimic the TD system by using the same brackets and simply welding on 2 studs to the top of the radiator assembly which then slotted into the rubber mounts just like the TD. Made it nice and tidy.


Electrics: This ended up being very easy (the main reason we all like mechanical diesel engines I guess!). As the starter was the same for my TD and the 200tdi, there is no change there. We ended up using my old alternator as well so again, no change needed.

The coolant temp sensor is mounted to the thermostat housing on the Tdi where the TD has it at the back of the block. It appears Land Rover were very nice and actually had a second cable in the harness in the correct position so the connector which has sat on my TD doing nothing with me not knowing what it is, is now the temp sensor wire for the Tdi and the old one is now redundant.

As I did not have the glow plug relay system with the engine, I simply connected the glow plugs in the same fashion as my TD was so I decide how long it heats for. Just need to remember I don’t need so long nowadays it seems!

Oil pressure and stop solenoid wiring again simply plugged onto the new engine.

The only bit I am not sure of currently is the relation between the temp sender and the gauge. I was told it would read wrong and currently, it does seem to sit just into the white but I am not sure where it should end up. The other option is to try a 200Tdi Defender engine sender in the block and see if this matches the current gauge? I will see how it goes and let you know.

Heater connections: The disco engine did not come with the coolant hoses that go to the heater matrix for internal heating of the cab. If it did come with some you could possibly adapt these to fit the defender (using copper plumbing pipe to make the joins with jubilee clips) Out initial approach was to adapt the old TD pipes, although due to the 90 deg bends needed in the pipe we opted for replacing them the proper pipes. The two pipes are BTR447 (£14) and BRT445 (£5)


Costs: Obviously this was one of the drivers for going this way and it certainly paid off (excuse pun!).

Ultimately it will depend on what you pay for the engine, and what comes with the engine, plus what you can salvage off your old lump.

In the end, I acquired the engine (minus PAS pump and brackets, starter, fuel filter assembly) and a radiator/intercooler assembly for £500 along with some coolant and intercooler pipes. I then bought the exhaust for approx. £135. The remaining pipe work for the fuel and radiator/intercooler connections, came to about £20. And additional £10-£15 was spent on belts, fuel pipes and unions. The starter, PAS, alternator, fuel filter, air filter were all sourced from TD.

The total so far then is £660/£680 not including service items or clutch assembly which I changed anyway to avoid removal in near future.

This is a brilliant saving over the money people want for Defender 200Tdi lumps and is also a good saving over the 300Tdi prices.

Recommendations: The Tdi is so much better than the TD. Unfortunately, I hadn’t driven the TD too recently prior to the engine change but even so, it was noticeably quieter than the TD. It also has a lot more go in it despite this fitment obviously having some potential constrictions in the pipe work etc. Economy I will have to wait and see but I hope there may be a slight improvement there as I won’t have to work the Tdi as hard.

I think our installation is reasonably tidy as it is an awkward fit. One option could be to take the cobbled together pipe work out and get one of these specialist firms to then make synthetic bespoke pipe work. It wouldn’t be cheap I guess but should improve the airflow and asthetics.

I will also have to see how the fan and PAS belts go. Obviously the mountings are spaced and aligned by eye so there is a chance of misalignment and rubbing but inspection after the first 150 miles doesn’t seem to show any of this. Time will tell.

Due to using the TD PAS pump, it saved any hassles with the hydraulic PAS pipe work as well. In fact we never took it apart so it didn’t even need any bleeding.

We were a bit apprehensive to start with but actually it came together easier than expected. Obviously to basically complete it in effectively 3 days and drive it 120 miles home is good going we felt.

We did put in a lot of hours between the 2 of us to get it done but some of it was spent looking at things, scratching heads, going to town to get bits etc. I guess total time was 34 hours with 2 people but I would have thought around 6 hours of that was going to town, lunch etc.

It did help that we had quite few bits of radiator/intercooler pipe work available to play with to try and find the best routing and set-up combinations. We have listed part numbers above for the intercooler pipe work. This will hopefully help any others who take this route.

If you have the time, space and are willing to play around a bit and do a few bits of fabrication, I would definitely recommend this as a cheaper solution to getting a Tdi.

I would like to thank Les Henson for his information prior to the change as it certainly helped immensely. Hopefully the above will just help some others and maybe provide a slightly different solution for some of you.

And Tony for the piece of pipe he supplied :)

Obviously the above is just our solution to the problem and the way we overcame the fitting. It ‘should’ work for any similar conversion although if it doesn’t we accept no liability or responsibility. It is recommended that part nos and prices are checked prior to ordering, MPN were correct at time of producing this although should all be double checked before you part with your cash!

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