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 pull oil through thte filter. 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 rather than an unheated one.

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. So, as with the heat exchanger, coolant heated filters are best.

One very good coolant heated filter is known as the Eckes WT after the original designer, a German called 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. VW oil coolers are brazed plate heat exchangers and hence these filters get piping hot in double quick time. Since the VW style oil coolers are widely available, both new and second hand, and the spin on filters are also very common and convenient to replace with no tools required, this is a very good filter; cheap, practical and high performance.

In the online shop you will the Eckes WT coolant heated filter and all parts that can be used to make your own.

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 £20. These filters have a thermostatic valve in one of the coolant hosetails. This will need to be removed 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.

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. The Eckes WT. Available in the online shop

Peugeot heated fuel filter.

Purflux heated fuel filter - found in older Renaults

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