300 TDI ENGINE CONVERSION INTO SERIES LAND ROVERS, We have developed the engine conversion for the 300 TDI engine that was used in the Defender and the Discovery 1994 onward models. The engine is basically the same with only the air filter being different. We recommend using the Discovery air filter as these are more available.

Most Discovery 300 TDI automatic models used Electronic Diesel Control (EDC). This engine is not suitable for the conversion.

To carry out this conversion we think you need a reasonable amount of mechanical knowledge and also electrical knowledge. You will also need facilities to lift an engine this heavy. You will also need a reasonable amount of tools to carry out the work. There is no welding involved with this conversion.
All the kits come with comprehensive instructions. We suggest that they are read through before commencing the actual conversion

This engine conversion is quite involved but we have developed a series of conversion kits, to allow the engine to be fitted with no welding work to the chassis, however the battery tray will need removing and the battery fitting under the Left Hand seat.  The Right Hand chassis engine bracket will need cutting back (a template is supplied to measure this in our engine bay kit) See part number SPCK338S3EBK and a bolt on “cap” is supplied to allow the 300 engine to fit. We have developed this conversion with customers in mind that have rebuilt their vehicles on to a galvanised chassis.

The Turbo outlet will need rotating for the conversion, and a new boost control unit mounting bracket is supplied. For this 2 holes will need drilling and tapping.

The 300 TDI alternator will foul the chassis, so we have relocated the 300 TDI alternator and again we supply a special mounting bracket and drive belt for this. These parts are supplied in the engine bay kit.  See part number SPCK338S3EBK

The 300 TDI flywheel housing will fit the Series model 2¼ litre petrol or diesel bellhousing with no modifications to the bell housing. However the 300TDI flywheel housing will need some alterations to suit the adaption to mate up to the Series bellhousing. This involves drilling out and tapping one hole to take a bell housing stud.

The original Left Hand 2¼ litre petrol or diesel engine block mounting bracket must be used with this conversion, so please retain this from the old engine.

The clutch is quite simple S2-2a models used diaphragm clutch with spacer, late 2a Diesel.

S3 models use 300TDI pressure plate and all models use S3 clutch plate.

As the 300 engine is turbo charged and intercooled we have developed the conversion kits to allow the intercooler to be fitted in models with head lights in the front panel, and all Left Hand Drive models, an alteration to the intercooler will be necessary and specialist aluminium welding will be required for this. Models with head lights in the wings there are no intercooler alterations required, we can supply intercooler pipe kits for all these combinations. We need details when ordering. See part numbers SPCK338S3C for series 3’s Right Hand Drive Models, SPCK338S2C for Series 2 and 2A. See SPCK338S3CLHD for left hand drive models

The cooling system is quite complex for the conversion, we have to use the 300TDI radiator and intercooler assembly including the frame work, you will need the header tank also from the donor vehicle. We have used a combination of specially made hoses and other hoses for the conversion, we have a specially manufactured a stainless steel jointer to allow the cooling system filler hose and heater return hoses to connect to the bottom hose, we supply a cable (or hand) operated heater shut off valve and the radiator mounting brackets with fixings, and stainless steel hose clips, temperature sensor and adaptor, some minor alterations to the heater connection hose will be required on LHD and models with flat or round heaters. Both the Defender and Discovery radiator frames can be used, alterations are required for the frames to be adapted to fit the vehicle.  See part number SPCK338S3W

A 13” electric fan will need to be fitted,

We can supply specially adapted oil cooler pipes for this conversion on part number SPCK338S3OCP

We make special exhaust systems for this conversion in a larger bore and to suite the turbo engine, for both Short Wheel Base and Long Wheel Base including Left Hand Drive models. These are made from aluminised mild steel and come with all the nuts, bolts and washers plus mounting brackets and hanger rubbers etc.

We can supply an air filter adaptor kit to allow the Discovery 300TDI air filter housing and intake hose to be used, this kit comprises of mounting bracket, pipe connecters and stainless steel hose clips nuts and bolts to suit. See part number SPCK338S3A

The electrical alterations will depend on the model of Series Land Rover you are fitting the engine in to. Series 2 & Series 2A models that are positive earth will need changing to negative earth and the amp meter removing. Other alterations will be required, negative earth models with a dynamo will need altering to take an alternator, Series 3 models will be easier to convert, we would recommend using the Land Rover workshop manuals to assist with the wiring changes for the relevant models and the also for the 300TDI donor vehicle.

We have designed the conversion kit components to make the conversion look as neat as possible and not look like a conversion.

Fitting instructions come with our individual kits.

From the donor vehicle you will need the following

300TDI engine with all ancillary items, i.e. alternator, starter motor, radiator / intercooler assembly, header tank, fuel filter and pipes, air filter and intake hose, accelerator cable.

Further Information

We have been asked many times about fitting the R380 gearbox from the 300 TDI Discovery, along with the transfer box.

When the 300 TDI engine is fitted to Series models, the engine bay is full with no room to move the engine forward, the R380 gearbox is very long especially if someone wants to fit the LT230 transfer box at the same time.  There is a version of the R380 with a short bellhousing, this is the same length as the Defender LT77 but is still much longer than the Series gearboxes.

The Series main gearbox is 16.25”- 413 mm long and the Defender model of the LT 77 is  22.25” – 565 mm long plus the adapter plate, the R380 Discovery is 25” – 635mm. These dimensions are from the bellhousing face to the transfer box face.

So the extra length will move the transfer box back. If someone wanted to fit the Defender LT 77 to the 300Tdi engine they could use the Ashcroft adaptor to fit it to the Series transfer box, as the vehicle is set up to be 2 wheel drive and selectable 4 wheel drive, however if you are  thinking of fitting the LT230 transfer box these are constant 4 wheel drive and the Series front axles are not designed for constant 4 wheel drive.

The ratio of the Series transfer box is similar to the Discovery LT230 ratio so with standard axle ratio of 4.7:1 it will be quite low in 5th gear.

The Series gearbox with overdrive fitted especially in LWB models is probably the best compromise of speed performance and reliability, as it is not easy to change the rear axle ratio on vehicles with the Salisbury rear axle fitted. SWB models can have 3.54:1 diffs fitted, but this is a massive jump.

The approximate MPH per 1000 revs on a SWB is 15MPH, with overdrive it is 19.25 MPH when running 205×16 tyres.

Models running 7.50 (235/85) x16 tyres the speed is 17.5 MPH and with overdrive it’s 21.75 MPH, these speeds are approximate but close enough to work out the revs required to do a certain speed.

We have many customers that are fitting 300Tdi engines to vehicles that have been rebuilt with galvanised chassis, fitting the LT77 or the short R380 gearbox plus the extra length of the transfer box adapter plate this will require the transfer box cross member and the hand brake pivot bracket moving back along the chassis and this will involve some welding work, customers do not want to do any chassis welding to a galvanised chassis.  Also the propshafts will need altering in length. There will be a front propshaft to chassis crossmember clearance problem when the suspension is fully extended.

The gear levers will need altering on some installations, along with the transmission tunnel cover and floor plates.  The exhaust intermediate pipe would need altering to go round the new position of the transfer box mounting.

We have developed the 300 engine conversion with no welding to the chassis, so fitting the later gearboxes will add a lot more complications.

So we feel that retaining the Series gearbox with an overdrive is much simpler and if driven sensibly will last many years with regular oil changes.

We would strongly recommend you speak to your insurance company before you do the conversion as some insurance companies do not allow modified vehicles on their books, you may need to change companies. There are plenty of specialist companies advertised in the Land Rover Magazines that can cater for modified vehicles. However they will probably ask for an engineer’s report. This is normal practice and most garages will be able to help you with this.

On completion of your conversion

You will need to inform DVLA of the new engine number, fuel type and capacity for your logbook
We would strongly recommend uprating the vehicles braking system and headlights

STEVE PARKERS LTD have been designing and fitting land rover engine conversions for over 30 years. we have also been manufacturing in house, conversion exhausts for over 20 years. we try to supply a comprehensive set of conversion kits, so that when the job is finished it looks like a factory installation. they are supplied as separate kits to allow them to be bought individually or they can be added to the basket and all bought at once depending on your requirements. the brackets in the kits are made for us by an engineering company with iso9001 certification.


Series 3 model shown for illustration purposes

Intercooler pipes turbo housing rotated, bottom hose and heater return pipe details.


Oil cooler pipes, alternator relocated, air filter bracket in place and heater valve


Aleration to RH long chassis bracket, showing engine bracket cap