AUTOMOTIVE ENGINEERING

Magnetised fuel feeds engine efficiency

Tom Shelley reports on a controversial magnetic field development which has potential to reduce fuel bills dramatically.

Improvements in fuel efficiency of up to 20% are claimed if strong magnetic fields are applied to fuel fed into diesel and petrol engines.

Power output too, it is said, can also be significantly improved under certain conditions.

The technique is further being investigated for enhancement of gas cookers, and oxy acetylene torches. It may therefore be of quite general usefulness, provided certain design rules are carefully followed.

The idea that magnetising hydrocarbon fuel can improve combustion and engine efficiency has been around since at least the 1930s. In 1936, Chinese fishermen are said to have been applying magnets to engine fuel lines in fishing boats in order to improve fuel economy. And during World War II, powerful magnets were placed adjacent to fuel lines for Merlin engines in Mustang fighters. The result is said to have been an increase in useful range by 15%, saving the lives of many crew members in the bombers the fighters were assigned to escort.

At the time, the idea was classified as a military secret, and subsequently forgotten. It required the use of large and heavy magnets, in order to generate the required field strengths, and is only now being revived with the advent of new, high strength magnetic materials.

Several companies in the UK are presently supplying magnets for use on fuel lines, but only one, so far, has been prepared to show Eureka hard evidence to justify their claims for the efficacy of their products.

Magno-Flo, based in Stirlingshire, Scotland, is run by mechanically minded John Brown, and engineer, Alan Barnes. Brown came across the idea of using magnets on fuel lines when he happened to read abut their use on Chinese fishing boats, in a book in his uncle's library.

Prolonged experimentation and trials have led not only to his conviction that the technique works, but also to the establishment of certain design rules.

First, it is essential to use the strongest magnets available, preferably neodymium iron boron. The magnets available from Magno-Flo are supplied in the form of short, cylindrical bar magnets. Those shown to Eureka are 22mm in diameter, and 10mm long. For petrol feed lines, it is best to apply the magnets on each side of the fuel line, in such a way that the north poles oppose each other.

For diesel fuel lines, the magnets should still be placed opposite each other, but with a north pole on one side of the fuel line, and a south pole on the other, so that the field lines run directly across the fuel feed.

In a low pressure fuel injected system, petrol or diesel, the magnets are best placed as close as possible to the injectors. If the system is high pressure, the magnets have little effect if applied at the injectors, and should instead be applied to the filter. If magnets can successfully be applied near the injectors, improvements are found in both engine power output and fuel efficiency, but if the magnets can only be applied to the fuel filter, improvements are only obtained in fuel economy. The magnets appear to work well through thin, mild steel fuels pipes or filter shells, but do not work through braided hose, particularly if the braiding is stainless steel.

The technique appears to work with any hydrocarbon fuel. Alan Barnes likes to perform a demonstration with a gas filled cigarette lighter. If one's hand is held above the flame, perceived heat is noticeably increased if a pair of magnets are applied to the body of the lighter.

John Brown says that he has also performed successful experiments applying a pair of magnets to the fuel pipe in an oxy acetylene torch, and to copper pipe in a gas fired Vokera indirect boiler. Best results with the boiler were obtained by placing one pair of magnets with North pole opposite South close to the burner, plus another pair, with poles opposed to each other, on the same pipe, but further from the burner. Applying the magnets increased the running hot water temperature from 65 to 69 deg C after 15 minutes..

A report entitled, "Investigation of the effects of the use of Magno-Flo magnets on diesel engines", by Dr Joe Cheung, of the Bolton Institute School of Engineering, shows improvements of from 5% to 10% in fuel consumption in an engine under load. The study involved bench tests on a Perkins T 4.236 engine. Improvements were particularly apparent at high speeds and loads.

Sun test results on a 2.8 litre Ford Sierra engine under load show use of magnets reducing carbon monoxide emissions from 0.9% to 0.53% and hydrocarbon emissions from 96ppm to 0.53ppm.

One of many testimonial letters from haulage contractors is one from W R Anderson of Robert Anderson of Dumfries shire. He says says: "Prior to fitting Magno-Flo to our Mercedes 1850, we carried out a fuel assessment. Over a total distance of 18,771 km, our fuel returns were 6.8 mpg. After the fitting of Magno-Flo, we rigorously tested over 31,384 km, and returned 7.5mpg. This gives an estimated annual saving, over an annual 230,000 mileage, of 3,000 gallons of fuel".

Some engines appear to achieve more benefit from magnetised fuel than others. Barnes cites the case of a Ford which showed 20 to 22% improvement in fuel economy, a BMW engine which showed 10% improvement, and a Japanese lorry engine which showed no improvement.

Consultations with academics reveal no obvious explanations why the technique should work, nor any fundamental reasons why it should not. Hydrocarbon fuel mixtures are complex. Almost all contain at least some molecules on which an electric charge can be induced at each end, and which might then be made to line up. It is also well known that passing a hydrocarbon fluid along a pipe induces electric charge. If the pipe is non conducting, fluctuating electric potentials of some volts are generated, and this fact forms the basis of the flow sensor developed by XL Technology and described in Eureka's December 1996 edition.

It is possible that the failure to work adjacent to high pressure injectors is because fluid passage past the magnets is too rapid and too violent to allow a lining up process to take place. It is also possible that a lining up process might affect liquid surface tension, which in turn would affect spray characteristics when emerging from an injection nozzle. Surface tension effects are unable to explain effects on the combustion of gaseous fuels. Charged double layer effects, the presumed source of the static voltages mentioned above, however, apply to both liquids and gases in contact with solid fuel supply tubes, burners or cylinder walls. The whole phenomenon may well have something to do with these.

Research into the possible scientific explanations is set to start about now at the Manchester Metropolitan University under the direction of research chemist Dave McCormick.

Magno-Flo

Design Pointers

* Applying a strong magnetic field to hydrocarbon fuel entering an internal combustion engine, engine cylinder, or burner appears to improve the efficiency of combustion

* Bar magnets placed each side of the fuel line appear to work best, with North poles opposing each other best for petrol, and North pole opposite South pole best for diesel.

* The magnets should be near injectors in low pressure injection systems, or applied to the fuel filter in high pressure injection systems. The technique can also be applied to gaseous fuels

Contact name and address: John Brown, Managing Director, Magno-Flo, 'Tigh-Na-Greine', Kinlochard, By Aberfoyle, Stirling FK8 3TL Tel/Fax 01877 387330

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