S.E.F.A.C. – 1930’s French Grand Prix disaster

In 1930 a company was formed in France known as Societé des Études et de Fabrication d’Automobile de Course, which, as its name implied, was for the study and building of racing cars. It was not a very successful firm, for they only built one racing car, and that has gone down in history as one of the biggest flops of all time. Using the initials of the firm the car was called the S.E.F.A.C., and it had been designed by Émile Petit, who had designed the successful Salmson cars in the 1920’s.

The object was to provide a French challenger for Grand Prix honours in the 1934-37 period of racing, which had a weight limit of 750 kilograms for cars. The S.E.F.A.C. was certainly different compared to other cars that were going to race in the mid-1930’s, such as the Mercedes-Benz, Auto-Union, ALFA-ROMEO, Bugatti and Maserati, especially in regard to its engine.

The Petit-designed engine was probably all right in theory, but was not very good in practical terms. There were two 4-cylinder blocks mounted side by side on a single crankcase, each block having a cylinder head with twin overhead camshafts. In the crankcase were two crankshafts mounted side by side and geared together, so that they ran in opposite directions. The right-hand crank drove a large supercharger from its rear end, and the left crank drove the gearbox, so that the propeller shaft ran down the left side of the wide chassis frame. This allowed the driver to sit low, but made for a wide car. The channel-section stell chassis frame, designed by Edmond Vareille, carried independent front suspension and a rigid rear axle, coil springs being used at all four corners. The whole car was far too heavy, weighing in at approximately 930 kilograms, while the bodywork made the S.E.F.A.C. one of the ugliest cars to grace the Grand Prix scene. The biggest failing was the engine, which produced only 250bhp, the lowest amount of power of any of the cars eligible for Grand Prix racing.

The first appearance of the S.E.F.A.C. was at the French Grand Prix at Montlhery, on the 23rd of June 1935. The car was to be driven by local driver Marcel Lehoux.


When Lehoux took the car out on the track and made a couple of slow laps, he found the S.E.F.A.C. to be extremely ill-prepared. The engine was short of power, the brakes did not work properly and the road holding was miserable. After Lehoux returned to the pits to explain the situation the car was pushed away and the entry was scratched.

The S.E.F.A.C. made no further appearances until 1938. A new formula for Grand Prix racing had been introduced in the same year, limiting supercharged engines to a maximum capacity of 3 litres, with no weight limit for the cars. This time the S.E.F.A.C managed to start the French Grand Prix at Reims on the 3rd of July, but its appearance was only marginally better than its 1935 debut. Driven by Eugene Chaboud, the S.E.F.A.C only managed two laps before retiring due to mechanical problems.

The third and final appearance of the S.E.F.A.C was at the 1939 Pau Grand Prix, held on the 2nd of April in the town located in the Pyrenees. Practice times show how uncompetitive the S.E.F.A.C. was. Fastest qualifier was Mercedes-Benz driver Manfred von Brauchitsch with a lap of 1 minute 47 seconds. The fastest time recorded by Jean Tremoulet in the S.E.F.A.C. was 2 minutes 14 seconds – 27 seconds slower! The S.E.F.A.C started on the 15th and last place on the grid. At least this time the S.E.F.A.C managed to actually do some laps, before retiring after 35 of the 100 scheduled laps due to mechanical issues.


The failure of the S.E.F.A.C was neatly summed up by a British driver who said: “I went to see the S.E.F.A.C. and could SEFAC-ALL.”

There however was one final twist in the S.E.F.A.C story. In 1948 the French press announced a new Grand Prix contender, from the firm Dommartin. On closer inspection, the Dommartin was found to be the S.E.F.A.C., fitted with a non-supercharged 3.6 litre engine and new, but no less ugly body.


The Dommartin never raced, and for many years it languished in a French museum, until it was purchased by English enthusiast Richard Lines in the mid-1990’s, who undertook a complete rebuild which lasted for 10 years. Lines restored the car to its 1938/39 specifications, but then sold the car before emigrating to Australia. I have no idea as to the current whereabouts of the S.E.F.A.C, nor if it actually managed to reappear on the track in historic racing. I hope that it did, as a “lemon” like the S.E.F.A.C. is part of the rich history of Grand Prix racing.

While this was the end of the line for the Dommartin racing car, they did attempt to produce another vehicle, at the other end of the motoring spectrum. The Petit design was an unusual curious open all-terrain vehicle. Under the 4-seater forward-control bodywork lay an 800cc flat-twin air-cooled engine in the tail, and a 5-speed gearbox. Production was minimal.


2 thoughts on “S.E.F.A.C. – 1930’s French Grand Prix disaster

  1. Hello Graham,

    The Sefac-Dommartin is at the moment in the Netherlands. They are working on it. Please One question Richard Line bought the car on auction it came form the Irish Motormuseum in Dublin. Do you now the daet and wich auctionhouse the car had sold ?
    Best regards

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