Sir Arthur Sutherland gave £10,000 of capital in early 1936 for the development of a new engine by the young engineer, Claude Hill. It displaced 2 liters and produced around 25 percent more power than the previous 1.5-liter unit. This 2-liter engine had larger carburetors, higher lift cams, and a dry sump. Encouraged by this new engine, Aston Martin began work on a new chassis into which it could be fitted. The new chassis was stronger than its predecessor, the wheelbase was one inch shorter than the earlier 1.5-liter cars, and the track was two inches wider. It had an advanced hydraulic brake system by Lockheed that worked superbly well, and few cars with drum brakes had better braking than a Speed Model Aston Martin.
Along with the new engine, a new gearbox was developed, able to handle up to 200 brake horsepower, with close ratios and constant mesh gears on the input and main shafts.
Two purpose-built Speed Models were built with the intention of competing at the 1936 Le Mans 24 Hour Race. Sadly, this did not take place due to a labor action by French workers. The two factory team cars were quickly sold to defray the cost of development. Work, however, did progress on more than half of the remaining chassis required to homologate the car for Le Mans. The final eight cars to be assembled, late in 1939 and into 1940, had steel-framed aerodynamic bodies designed by Claude Hill. They were given full competition specification, with a flowing nose and long tapering tails with sleek wings fully enclosing the wheels. The main body panels were constructed of light alloy while the wings were formed from steel. This new design made its appearance at the 1938 Earl Court Motor Show. The final iteration of design had headlamps that sat behind the founded radiator shell.
by Dan Vaughan