Before Jaguar started to produce the D-Type, a small group of pre-production cars were made starting with the prototype chassis XKC401. This car became the testbed for the new ideas that Malcom Sayer and others would implement into their already winning C-Type design. Our feature car also has the distinction of remaining in largely original condition and is easily spotted by its long-time OVC501 registration tag.
Even before the 1953 victory at Le Mans, it became clear to Jaguar that a new car would be necessary to stay ahead of Ferrari, Alfa Romeo, Aston Martin and Maserati. Sir Williams Lyons, the founder of Jaguar, assembled a team of Engineers including Malcom Sayer, an aviation aerodynamist, to create the all-new D-Type.
The first prototype was built up similar to the production cars with an innovative chassis structure. It used stressed-skin engineering, incorporating the framework with riveted aluminum body panels to form a single rigid structure. Such design made the D-Type one of the first cars to use monocoque construction.
The prototype was fabricated using the lightest materials possible including aluminum and magnesium alloys but many of these were replaced by steel for series production. A good example of this is the front sub frame which is fabricated in aluminum on the prototype and steel on the later versions for ease of repair and durability.
Design requirements for the D-Type said it should be lower and shorter that its predecessor. Most of the shape came from mathematical computation with the help of Malcom Sayer. Initial tests on the unpainted prototype revealed a top speed of 178 mph, almost 30mph faster than the Type-C.
The XK-based engine powering the D-Type played a large role in helping achieve a high top speed. It was both shorter, thanks to dry-sump lubrication, and more powerful than the previous engines. The combination of a revised block, larger valves and triple Weber carburetors helped the engine achieve 245 bhp.
Numerous details separate the D-Type Prototype from all the other cars. This includes a unique cockpit with gauges on the left side of the steering wheel and a riveted head cowl that was properly formed on subsequent cars. The prototype was always retained as a test bed and was never actively raced.
It was first tested on April 13th, 1954 and later was used at the Le Mans test to set the unofficial lap record. The car was continually used for testing items such as the ZF differential de Dion-tube rear suspension. For a long time it was displayed at the Jaguar/Daimler Heritage Trust. More recent outtings include the 2006 Goodwood Festival of Speed and an appearance at the 2010 Villa d’Este Concorso d’Eleganza.