1923 Avions Voisin Type C6 Course "Laboratoire"

1923 Avions Voisin Type C6 Course "Laboratoire"

“Commercial considerations are fundamentally incompatible with revolutionary ideas.” Gabriel Voisin (1880-1973)

Gabriel Voisin was the man who made the first powered flight off water, in a seaplane, and traveled at tree top height from the Billancourt bridge to the Sevres bridge on the river Seine in France on 8th June 1905. The aircraft company he set up created the Voisin III military bomber aircraft of World War I. After the Great War Voisin decided that aircraft were an ugly weapon of war and he ceased building them. A similar effect to that experienced by Alfred Nobel in his creation of the Nobel Peace Prize when he saw his invention, dynamite, enable the creation of the high velocity repeating rifles, machine guns and artillery which were then used with such deadly effect in the Russo-Japanese War of 1904-1905 and then in the Great War of 1914-1918. Voisin moved on from weapons of war and concentrated on the creation of imaginative and beautiful motor cars.

And what cars he did create. In the post Great War period Voisin created some of the most beautiful cars one could imagine. Cars that were easily the equal of the Bugatti. In the twenties Rudolf Valentino drove one around Hollywood. In 1923 Gabriel Voisin decided to create a new Grand Prix racing car. He had tried the previous year and because he had rather creatively interpreted the rules his cars finished up being banned. Gabriel Voisin put his imagination to work to create a car that would fit into the new rules of 1923 and produce the best possible results. He got together with French designer Andre Lefevbre (who is famous for his designs for Citroën including the 2CV and the iconic DS series).

The C6 Laboratoire was built using aluminium alloys wherever possible and was created in the shape of an aircraft wing. If a car is simply shaped like an aircraft wing however it will have a tendency to lift at high speed (The Jaguar E-Type for example has this tendency to lift as one approaches its top speed). Voisin appears to have understood this and so the front of the car is shaped to create a down-force by directing air upwards. This has the effect of creating a low pressure area under the car helping to keep it from any tendency to lift. Similarly the rear treatment of the car has a wing shape to nicely close out the air-flow at the rear but has a slightly up-swept under-section which enhances the creation of a low pressure area under the car. The car might be fabricated of flat sheet aluminium alloy but the aerodynamics are superbly thought out. Voisin and Lefevbre had in fact created what might be thought of as the first rudimentary ground effect Grand Prix racing car.

The C6 was powered by a 2litre engine that needed more research and development in order for Voisin to achieve competition success. Of the four cars entered in the C6’s first competition only one finished. It managed to finish in a respectable fifth place however. That failure rate is not unusual for a debut appearance of a new car. Even the likes of Maserati have suffered high failure rates in competition in the fifties and sixties.

Looking at the car it is very clear that Gabriel Voisin has made every effort to make the car as easy to repair as possible. Everything is accessible. There is a lot of Andre Lefevbre’s thinking in the sheer functional practicality of the mechanical layout I suspect.

One of Andre Lefevbre main contributions to the design of the C6 Laboratoire was the engine. Gabriel Voisin’s cars had previously used sleeve valve engines but it had not proved possible to get race winning power from such an engine. So Gabriel Voisin commissioned Andre Lefevbre to create a new engine for him with conventional valves. The fifth place achieved by the car that finished in the 1923 Grand Prix is testament to the potential of both the car and the engine. This car is presented at the Mullin Automotive Museum.

Descriptions & pictures by revivaler & velocetoday & jalopyjournal & hiveminer & other