"200Di" diesel conversion - how to do it

Developed for Series Land Rovers by Glencoyne Engineering


 

 

(NOTE: following further development work on this conversion, I updated these notes on 13/10/07 to incorporate the latest modifications.)

This is not intended to be a comprehensive step by step instruction manual, but a guide which will help you with some of the trickier parts of the conversion.  To attempt this conversion you need a reasonable degree of mechanical ability and some common sense.  Working on old Land Rovers can be dangerous, especially if you use incorrect tools and unsafe working methods.  Make sure you carry out your own assessment of the risks at every stage of the conversion, and take whatever steps are necessary to minimise those risks.  I cannot carry out your risk assessment for you, and I cannot be held responsible if it all goes wrong and you end up in hospital or worse.

Before you start, you need to get hold of a Discovery 200TDi engine.  Try to ensure that it comes with the following:  starter, vacuum pump, lift pump, injection pump and injectors, alternator mounting bracket, turbo (doesn't matter if it is worn out, you only need the mounting flange), fuel filter assembly, heater plug timer and wiring, complete engine bay wiring loom, battery cable and the pipe from the crankcase breather to the air filter.  You do not need the power steering pump, the clutch or the air filter assembly and you will only need the alternator if you don't already have one.

So, the first stage is to remove the battery, drain the cooling system and then remove the old engine as per the workshop manual.  Once the engine bay is nice and clear, remove the air cleaner bracket and then cut back the battery tray as in the photo below, removing the support leg which goes onto the engine mount.  The battery will be relocated under the passenger seat.

Now you need to turn your attention to preparing the engine.  Firstly you need to strip any un-needed ancillaries - cooling fan, power steering pump, alternator, engine mounting brackets (keep the four large bolts to fit the new engine mounts), clutch and of course the turbocharger.  The turbo is held on with four nuts and studs which may be very tight and are almost inaccessible with anything other than a small open end spanner.  If the turbo has done a lot of miles or is in dubious condition it won't be worth a lot.  So don't waste time struggling with the nuts.  Take a 9 inch disc cutter and chop the turbo off at the mounting flange, making sure you do not catch the ends of the studs with the grinding disc.  You can now undo the nuts easily with a good quality socket.  Keep the mounting flange, you will need it later for the exhaust. There are also two oil lines (feed and return) from the turbo to the engine block which need to be undone before the turbo can be removed.  You should end up with something that looks like this:

The turbo oil feed and return lines need to be blanked off.  If you have access to welding equipment, you can just unscrew them from the block, weld a bolt inside the end to seal them, then refit them.  Otherwise you will have to hunt around for some suitably sized blanking plugs.

Round the other side of the engine, the oil filter housing has connections for an oil cooler.  We don't need that, so the filter housing has to be converted to 2.5 non-turbo spec.  Undo the two bolts in the end plate, withdraw the plate and remove the thermostat and spring.  Replace the plate, and then blank off the oil cooler connections with two Rover V8/200 TDi sump plugs (part number 603659) and copper sealing washers.

Bellhousing preparation:  the Disco engine will bolt up to the Series bellhousing quite happily, but there is a problem.  At the bottom of the bellhousing, a Discovery has four long M10 bolts which go through the flywheel housing and screw into the cast alloy stiffening plate between the engine block and sump pan.  I suspect these bolts are quite important in reducing vibration and preventing undue stress at the join between engine and gearbox.  However, the Series bellhousing does not have holes for these four bolts - instead it has holes for three studs, which are not present on the Discovery flywheel housing.  Many people have ignored this problem and simply bolted the Disco motor to the Series bellhousing with no ill effects.  But if you want to do a proper job, I strongly recommend that you do the following.

First, remove the flywheel from your Discovery engine, followed by the flywheel housing.  There is a stud in the flywheel housing which needs to be removed (see photo below) and there may also be two steel dowels in the rear face of the flywheel housing.  These must be removed if present.  One of the dowels can be seen next to my thumb in the photo below.  To remove studs, simply run two nuts onto the stud, then turn them against each other to lock them together.  If you turn the innermost nut anti-clockwise with a spanner, the stud should now unscrew from the flywheel housing.  Offer up the flywheel housing to the gearbox bellhousing and secure it with a couple of M10 nuts.  Now you can use it as a drill guide to drill out the four bottom holes through the bellhousing flange using a 10mm drill bit.  Refit the flywheel housing and flywheel to the engine as per the workshop manual.  You will need to fit a new housing to block gasket and crankshaft oil seal - don't try reusing the old ones, it isn't worth the risk of having to take the engine out again if they leak.

Now you can fit the clutch.  The 200 TDi flywheel will take the 9.5 inch Series clutch plate, with either the Series 2A (diesel) or Series 3 cover, so if the clutch from your old engine is in good condition you can probably swap it straight over.  If you are replacing a petrol engine in a Series 2/2A with the 9 inch coil spring clutch, you will need to upgrade to the 9.5 inch clutch.  Make sure the clutch plate is perfectly centred - I use an old gearbox input shaft for this job - worth paying a few quid for a scrap Series gearbox just to get this bit. 

Last job before fitting the engine is to sort out some engine mounts.  Assuming you have just removed a standard 2 1/4 petrol or diesel engine from your Landie, simply unbolt the mounts from this and bolt them to the 200 TDi block.  On the nearside there are two sets of threaded holes - use the front set. 

Now you can fit the new engine (as per the workshop manual) using Series diesel engine mounting rubbers, or Defender 200TDi items.  If you use the latter you will need to grind down the edges so that they fit the engine mounts.  For the four bottom bellhousing bolts you will need M10x100 bolts and spring washers, also two M12 nuts ground to a wedge shape to use as spacers.  The outer two bolts come through the bellhousing flange at a place where it slopes slightly, so you need the wedge shaped nuts to compensate for the slope.  The clearance for the heads on the outer bolts is very tight, and if you can get socket head (Allen) bolts, they might be easier to tighten.  For the other bellhousing studs use M10 nuts and spring washers.  The photo below shows the four bolts and two wedge shaped nuts in place, together with the three redundant holes in the Series bellhousing. 

Plumbing in your new engine will be fairly straightforward, provided you do things in a sensible and methodical fashion.  Starting with the alternator, you have several options.  If your old engine has a good alternator, simply remove the 200TDi alternator mounting bracket, and transfer the alternator complete with mounting bracket from your old engine.  You will need to substitute M8 metric bolts for the two which bolt the front face of the cast alternator bracket onto the engine block.  Alternatively you can bolt a Lucas 16ACR alternator straight onto the 200TDi bracket as shown below, but if you are using your Series alternator, the front plate will need to be rotated to put the adjuster lug in the right place.  In both cases you will need a military type double pulley (part 574870) to align the alternator belt with the water pump pulley, as in the photo below.  The final option is to use the Disco 200TDi alternator with a pulley from a VW Golf or similar. You need to measure the distance around the pulleys to find out what length fan belt you need.  The installation below uses a belt from a series 3 109 V8.

You can now go on to wire up the rest of the electrics.  How you do this will depend on the year and model of vehicle, and if I were to provide detailed instructions for every variant of Series Land Rover I would never find the time to get this page finished.  In all cases you will need to relocate the battery under the passenger seat and make up a clamp to hold it securely in place.  If you have the positive battery lead from the donor Discovery, this should comfortably reach from the starter solenoid to the battery in its new location.  The battery negative lead should be bolted direct to the engine/gearbox assembly, with an earth strap from the engine/gearbox to the chassis.  All the fixing points for this leads need to be nice and clean, and securely bolted.  Series 2/2A Landies had a battery tray under the passenger seat which should take an 069 battery, but if you do not have the battery tray, you will find an 073 will fit in the front LH corner of the underseat tool locker and will have plenty enough power to fire up the engine.

The alternator can be connected as per the Series 3 diesel wiring diagram (using the original wiring if you are converting a Series 3).  The starter solenoid wire (red/white) should connect straight to the solenoid on a diesel vehicle, but for petrol vehicles with a separate starter solenoid you will have to extend this wire.  For pre 1967 vehicles with a starter button, you can still use this to actuate the starter solenoid - just connect a positive supply to one side, and connect the other side to the spade terminal on the starter solenoid.

Being a fairly modern diesel, the 200TDi has an electrically operated stop solenoid, rather than a cable operated system.  If converting a petrol vehicle, simply extend the + wire which previously fed the ignition coil, and connect it to the stop solenoid.  If you are converting a diesel Land Rover with late series 2A or series 3 combined starter and glowplug switch, you will find that when the starter is operated it disconnects all the switched electrical circuits.  So you will need a 4 pin relay, which when actuated connects the glowplug feed to the stop solenoid (glowplugs are powered while the starter is operating).  The actuating feed for this relay should be from the red/white wire to the starter solenoid.  You will also need to identify a live switched feed (the + feed to the brake light switch is ideal) and connect this to the stop solenoid also.

Finally on the electrical front, you need to do something about the glowplugs.  Easy if you are converting a diesel as you already have a switch and wiring.  For a petrol vehicle, try to get hold of the glowplug relay and wiring from the donor Discovery.  Connection is very simple.  Of the two heavy leads, the brown goes to the battery connection on the back of the starter solenoid, the black/yellow wire connects to the glowplugs.  Of the thinner wires, black is earth, white connects to the ignition feed (also white), red and white connects to the starter solenoid (also red and white) and the brown and white wire connects to the blue and white wire which runs from the choke cable switch (which you will have removed) to the cold start warning light.  Now when you switch on the ignition the yellow warning light should come on for a few seconds (to show the heater plugs are working) then go out.  You will find that, except in very cold weather, this engine should fire up easily without any need for glowplugs, but it makes sense to wire them up just in case they are needed.

On the next page we will look at fuelling, cooling and exhaust systems.  Click here to continue.