Discovery 200TDi and 300TDi conversions - done properly

For Land Rover 90, 110 and 130 - by Glencoyne Engineering



"Just to let you know the trip home (120 miles) went without a hitch... the engine and power delivery were superb.  Back at home the fluids were all as they were when we left Thetford and there are no leaks. BRILLIANT :)!! The power improvement is stunning. To use that often used phrase - it pulls like a train! It seems like I've got a new vehicle.  Many thanks for the work and efforts you put in. I'd have absolutely no hesitation in recommending your company." - SM, London

"I just wanted to let you know that I'm really pleased with my 90 following the TDi transplant, it has absolutely transformed the performance and generally improved the vehicle." - DB, Norfolk


When Land Rover launched the first series Discovery in 1989, they had an instant smash hit on their hands.  It may have looked like the result of an illicit mating between a Mitsubishi Shogun and a Mk2 Transit, but the underpinnings were pure Range Rover, and in the new 200TDi power unit Land Rover at last had a diesel which was as powerful, durable and economical as anything the Japanese had to offer.  But as owners are now finding, seam sealant and protective wax were alien substances to Solihull in the early 1990s.  The Discovery was shoddily built from poor quality materials, badly finished and lacking in any kind of corrosion protection.  For a vehicle based on the old Range Rover body structure (itself already notorious for rot) this was bound to end badly.  End result is that the scrapyards are now filling up fast with terminally rotten Discos. 

That is all bad news if you own an early Discovery with a short MoT, but great if you have a Ninety or One Ten with a poorly engine.  The Discovery TDi engine is very similar (though not identical) to the unit used in the Defender from 1990 onwards, and can be made to fit the earlier vehicles, usually at no more cost than repairing your old engine.  Fitting a TDi will transform the performance of any older 90 or 110 (or indeed 130) whether it has the four cylinder petrol engine, 2.5 diesel or even the '19J' turbo diesel.  The Disco 200TDI will give you 111 bhp and 30+mpg, against 85bhp and 23-25mpg for the old turbo diesel.  And it will run on vegetable oil.  Enough said.

I have done a fair few of these conversions now, replacing 2.25/2.5 petrol, 2.5 diesel and turbodiesel.  I do the conversion properly, including the long through bolts in the bottom of the flywheel housing.  Many people don't bother with these, which explains why so many TDi conversions leak oil from the back of the engine.  I use top quality OEM engine mounts which make a huge difference - four times the price of the cheap 'pattern' mounts that most people use, but why spoil a good conversion for the sake of a few quid? My conversion uses the Discovery air filter, mounted so that the filter element can easily be changed without having to dismantle half the vehicle to get to it.

As the supply of dead 200TDi Discos has started to dry up, I have now developed an alternative, using the 300TDi fitted to 1994-98 Discoveries.  This engine is the same size and power output as the 200TDi, but has a number of significant differences (for more information on the TDi family click here).  This conversion requires the old engine mounts to be cut off and new ones welded on, so if your Land Rover has a galvanised chassis you may prefer to go for the 200.  But it is now taking me 2-3 months to source a good 200TDi engine, whereas 300s are plentiful.

Every conversion is different, so I have broken down the conversion price to ensure that you only pay for the items you need.  Engine is supplied on an exchange basis - if you wish to keep the old engine, add £100 to the cost.

Basic conversion - includes engine (second hand, inspected and tested), new timing belt kit, crankshaft front and rear oil seals, strengthened clutch release fork, new engine mounts, filters and fluids, radiator and intercooler, all pipework etc, road test and 3 months warranty.  £1,695

Electric fan: you will need this if you do not already have one fitted.  Includes thermostatic control unit. £150

New clutch: The TDi will take the same clutch as your old engine, so if you have recently had the clutch replaced I can swap it onto the new engine.  But if your clutch has done a significant / unknown mileage I recommend replacement. Price is for a 3-part clutch kit from a reputable manufacturer (usually Borg & Beck).  £90

Exhaust: If your old engine is the 2.5 turbodiesel I can reuse your old exhaust provided it is in good order. However it is a narrower bore than the TDi type and I recommend replacing the system with a new one.  I now use the later 300TDi system on both 200 and 300 conversions.  Cost (including new mounting brackets, rubbers etc) £120  (Ninety) £135 (One Ten)

Heater plug timer and wiring - required when converting from 2.25/2.5 petrol.  For diesel conversions I retain the existing key-operated heater plugs.  £40

Power steering pump delete kit: required if fitting a TDi to a vehicle without power steering - mainly early 110s and military vehicles. (Note: I can fit power steering if required - see below.)  £30

Power steering conversion: I can easily accommodate this at the same time as fitting the new engine. Price to include reconditioned steering box and drop arm, new pipework, reservoir, good second hand pump etc £450

Transfer box replacement: most older Defenders have the 1.410 ratio transfer box which is suitable for normal use.  Some early petrol vehicles, and many ex military One Tens, have the 1.6 ratio box which is far too low geared to make the most of the new engine's performance.  I can replace the transfer box with either 1.410 or high ratio (1.2), but the latter option is not recommended for heavily laden One Tens or vehicles on very large tyres.  Price depends on whether you want a second hand or reconditioned box.

Non-standard vehicles: If your vehicle has any unusual options such as front-mounted winch, auxiliary lights, extra heating equipment etc that may make the conversion more difficult, any additional workshop time required will be charged at my standard hourly rate.

Got an engine already?  I can fit it for you - ask for a quote.

Military vehicle?  I reckon that about one in three of the vehicles I convert is ex Army, replacing the old 2.5 non turbo and usually fitting power steering at the same time.


Quite a few Land Rover specialists are now advertising Disco engine conversions, and some of them are a bit cheaper than my conversions.  But before you decide who to use, make sure you ask the following questions:

  • Does the price include a new timing belt, tensioner and rollers?

  • Does it include new engine mounts?

  • Does it include an oil change, new oil, air and fuel filters?

  • Is the flywheel housing drilled and tapped for the four extra studs needed to bolt the gearbox to the engine all the way round the bellhousing?

  • Is the flywheel housing counterbored to take the four long bolts at the bottom which secure it to the block stiffener?

  • Is the completed vehicle comprehensively road tested?

  • Does the conversion come with a 3 month warranty?

If the answer to any of these questions is 'No', then the conversion isn't as good as it should be.

Don't forget, a TDi-engined vehicle will always be worth more than any other Land Rover engine option - provided the conversion has been done properly.

My workshop is located in Banham, Norfolk - see contact page for details.  If your vehicle requires other work I can usually deal with this at the same time as the engine conversion - ring me on 01953 888731 for a quote.