Heated filters

A heated fuel filter is highly recommended. Vegetable oil is thicker than diesel, so trying to filter cold vegoil through a standard diesel filter will require much more effort.  This will put strain on the injector pump and fuel pump and increases the chance of air getting into the fuel lines due to the extra vaccuum required to filter the oil. With a heated filter, the vegetable oil is thinned and so passes through much more easily. Not only does this ease the strain on the IP but it ensures free flow of fuel to the engine. Furthermore, there is much less chance of the filter becoming blocked by thick fatty blobs which greatly extends the life of the filter element. All in all, a number of very good reasons to use a heated filter over a standard filter.

As with the heat exchanger, the ideal source of heat for the filter is the cooling system via which the filter can be supplied with a constant supply of water at 70-80°C. The filter can be heated electrically, although with such a vast amount of heat generated by the engine itself, there should be no need to drain on the cars battery and alternator. Some vegoilers make filters which use electric heating elements at startup. Bear in mind though that there is no point heating oil without heating the injectors and pump since all the heat will be lost to the pump, engine block and injector lines - they act as heat sinks when the engine is cold.

In the online shop you will find a superb heated filter which has proven to perform significantly better in tests than the Cav filters and the Eckes.

The head is made from cast aluminium so it is light, has superb heat transfer properties and is 'A' rated for materials compliance. Heat is delivered to the head via the coolant water which enters via a 16mm hose port at the front, flows around the back of the head and exits via another 16mm hose fitting at the front. As a result, the head becomes piping hot extremely quickly. Heat is transfered into the filter canister, warming the oil as the vehicle warms up. When the fuel is switched to vegoil, the contents of the canister becomes extremely hot within minutes. The fuel is heated as it enters and as it exits the filter assembly.

The filters are easily changed by undoing the allen key bolt, removing the canister taking out the element and replacing with a new element, then screwing the canister back on to the head and using the pump in the head to reprime. Filter elements are commonly available in many brands and are cheap to buy.

Certain cars, particularly diesel Peugeots and some Renaults, are fitted with Lucas/CAV/Rotodiesel heated fuel filters as standard and therefore don't require one to be added for conversion to vegoil. The more recent models have filters fitted to the engine block with purpose built mountings and may also have coolant water flowing through the mountings. For cars that don't have heated filters already, we highly recommend that one is acquired! The earlier Renault and Peugeot diesel models were fitted with self-contained coolant heated filters which are ideal. They can be obtained from scrap yards or specialist breakers, though they are becoming harder to find. The going rate is currently about £10 -£15 but rising! These filters have a thermostatic valve in one of the coolant hosetails. This will need to be prised out in order to get the full flow of coolant through the base of the filter. Please be aware that there have been reports of the heat breaking down the glue from certain brands of filter elements when this is done. See www.vegburner.co.uk for more details.

 Another heated filter that can be used is known as an Eckes WT after the original designer Eckhard Wernick. It is fabricated by using a customised bolt to insert a VW oil cooler between a standard filter head and the spin on filter cartridge. Since the VW style oil coolers are so easily found at scrap yards, this is an ideal and cheap solution. 

Note: the heat exchanger provides the primary source of heat. A heated fuel filter is not for warming the oil to operating temperature. It is to improve the efficiency of fuel filtration.

Highly efficient coolant heated fuel filter. Available in the online shop complete with fuel connectors and a heavy duty piece of lagging

Peugeot heated fuel filter.

Eckes WT - A great homemade solution