Vegetable Oil Conversion - Engine Bay

The engine bay is where most of the conversion items are fitted, and due to the moving parts and temperatures of items under the bonnet is where the greatest care has had to be taken.

I have decided to follow the path of the fuel so as you read down you are following the same stages the fuel goes through.

The first component the vegetable oil reaches is its own fuel filter. This is a standard Bosch filter head with a VW oil cooler conversion. It uses a standard Land Rover fuel filter which keeps spare parts nice and simple. I found the VW oil cooler in a salvage yard on a Skoda.

The oil cooler fits to the Bosch fuel filter head with a special bolt purchased from BioTuning ( The normal Land Rover fuel filter can then be screwed to the bottom. I wanted to mount the fuel filter in the engine bay, but decided the extra weight hanging on the bulkhead, and the tight confines for hanging another fuel filter were prohibitive of that. I had already made a bracket out of some angle for the heat exchanger so with the success of that (I am not a natural welder) decided on the more ambitious fuel filter holder. This uses the clutch cylinder housing as a fixing point and holds the vegetable oil filter at the same height as the original to aid bleeding.

The bracket was made from scrap angle and consisted of 3 pieces. One was drilled to match the three fixing bolts for the clutch housing plate, and the angle measured.

To this was welded an upright which would give the extra height required for the filter. The third piece was mounted horizontally and drilled for 2 x M8 bolts to secure the Bosch Filter head too. The entry and exit pipes for the coolant were position to face the passenger side of the vehicle to allow for the shortest run of 15mm ID heater hose. It was sprayed with primer.

Once the vegetable oil passes through the heated fuel filter arrangement it travels down a short length of fuel line to the main heat exchanger. This was a brand new part from ebay ( and as such required its own custom bracket.

The bracket was made to mount the space on a 200TDi engine which would normally be occupied by the Air Conditioning pump. It was made with three pieces of angle. One piece folds over and uses the timing case cover bolts and two pieces are welded to this to create a channel for the heat exchanger to sit in. It is held in place by a metal strip and nuts using bolts welded to the side of the angle.

The main heat exchanger gets its coolant from the engine via the fuel filter heat exchanger. This was more practical for hose routing than cris crossing back and forth in the engine bay. It is plumbed in series with the vehicle heater matrix. Fitted between the engine and the two heat exchangers is a T-piece.

This T-piece contacts a temperature sender for one of the two cockpit gauges. This measures the temperature of the coolant in real time entering the heat exchangers.

This allows the most accurate indication of coolant temperature, and coupled with the second gauge will hopefully prevent premature switching of fuel tanks.

Once the fuel has left the main heat exchanger it travels the short distance to the "Supply" fuel solenoid. This selects which fuel pipe the lift pump is drawing from, and thus which tank. The fuel, now being pulled from the Vegetable Oil tank after activating the solenoid is pulled/pushed through by the lift to a sensor block for the second gauge.

The second gauge sensor is a small sensor block fitted in the fuel line. The fuel, upon leaving the main heat exchanger passes into this sensor block, where a second temperature sender is relaying back the temperature of the fuel.

This was initially planned to allow thorough testing of the system prior to full time use, but has been left in as a useful indicator of the state of the system. Finally the fuel passes through a cheap disposable fuel filter and into the injection pump. The fuel filter is required due to so many components now being fitted to the system after the main filter.

Fuel spilled off by the engine leaves the injection pump and passes through a second solenoid which diverts it to the DERV or Vegetable Oil tank. The solenoids are individually controlled to allow for the greatest flexibility of purge time and the ability to dump DERV into the Vegetable Oil tank to thin out the oil if need be.

Coolant for the heat exchangers leaves the engine, travels through the temperature sensor and into the fuel filter heat exchanger. From there it travels into the main heat exchanger and then to the vehicles heater matrix and back into the engine.

There are many more pictures of the engine bay and sections of the build in the Gallery section of the site.



Manuals & Downloads
You Tube Channel
Online Shop (New)
Malcolm Bell
Contact Us
Tech Write Ups
--- Land Rover Crane
--- Heavy Duty Tablet Mount
--- HID Headlight Upgrade
--- Paint Job 1
--- Homemade Searchlight
--- Homemade Radiator Muff
--- K&N Air Filter
--- Hardtop Fume Curtain
--- Rear Worklamps
Cooking Oil Conversion
--- Introduction
--- Components
--- Engine Bay
--- Cockpit
--- Twin Tank Installation
--- Testing
--- Conclusion

Graeme Shorten - L4NDROVER.CO.UK -
Copyright 2014