Single Seater

Sutherland Aston Martin, 1936-1940

The Single Seater

In 1939, during the period when the Cross rotary valve cylinder head was in development to fit to a standard ‘Speed Model’ cylinder block, one of the last remaining Speed Model chassis was modified in the works’ racing department. In order for it to be a suitable basis for a narrow track racing car the chassis was ‘cut and shut’ by three inches each side of the centerline to make the entire chassis six inches narrower. In addition one off front and rear axles were made with a four foot two inch track, four inches narrower than standard. Fitted with a crude and rather ugly single seater bodywork it was planned that the car should be raced at Brooklands in order to publicize the new Cross rotary valve engine.

However, when the Cross valve conversion was found to be disappointing, a decision was made to use the suitably rebuilt Speed Model engine, from the ex. Dick Seaman Ards TT car that had sized up during the race. This was a racing specification engine, built in the competition department and had been lying on the floor at the back of the factory since 1936. To enable the new lightweight racing car to reach as high a speed as possible a 4.0:1 axle ratio was fitted along with a special set of constant mesh gears in the gearbox. In this form the car was capable of 60 mph in first gear, though it was quite difficult to get ‘off the line’ from a standing start. Fitted with simple wings, Gordon Sutherland tested the new racing car on the public highway around Feltham and found that because standard Speed Model springs had been used, the much lighter car was almost undrivable, with all four wheels regularly bouncing off the tarmac on bumpy roads. Since Brooklands was known to be notoriously bumpy they bought the car back to the workshop to fit a special set of lighter springs. The suspension was also slightly modified with solid bronze bushes in the front axle trunnions instead of the normal ‘Silentbloc’ bushes.

The original works drawing of the layout of the new car shows a central driving position with an extension to the gearbox to the right (much like the option for the ‘International Le Mans’) to enable an outside gear lever. However, the few photographs of the car in its original condition do not show this, and it is thought that the driving position was in fact ‘offset’ from the centre of the car. The steering box bracket had a significant angle to allow the steering wheel to be much more central than normal.

Specification

As Team Cars but;

The chassis was six inches narrower.
Track: 4’ 2".
Weight: 16 cwt.
Close ratio constant mesh gears were fitted in the gearbox. The final drive ratio was 4.0:1.

The car was fitted with very lightweight racing offset single seater coachwork with high head faring with leather covered pad behind the cockpit. No screen was fitted. Instruments included a six inch Jaeger rev. counter to 9000 rpm, flanged oil pressure gauge to 100 psi and matching water temperature gauge. Cycle type wings mounted on spring steel mounts bolted directly to the brake back plates were fitted so that the car could be used tasted on the public road.