Jaguar cars considered the idea of building a low drag sports car racer, based on the D-Type, which had been discontinued five years before.
The concept was tested by designing a fixed head coupe, with a monocoque structure, which would be rigid enough to withstand the stresses of racing.
Lightweight aluminium body panels would be used, whilst the front sub-frame supporting the engine and front suspension would be made of steel.
The incline of the windscreen was increased, and cooling vents for the rear brakes were added near the rear windows.
Apart from the windscreen, perspex replaced the use of glass elsewhere.
It was powered by a tuned version of the 3.8 litre XK engine as used in the later versions of the D-type Jaguar.
Only one prototype was built, and although it produced improved performance over the production E-Type, the increase was not sufficient to warrant development, and the project was shelved.
The Lightweight E-Type
In 1956, Jaguar made the decision to exit car racing. However, when the E-Type was launched in March 1961, it was at a time of growing interest in GT cars.
Compared with purpose-built race cars like the Ferrari 250 GTO, the E-Type was completely outmatched. What was needed was to create a lighter version of this road car.
Consequently, the company decided to re-enter sports car racing and, in early 1962, instigated a project to develop a lighter version of the E-Type for endurance racing.
The result was a decidedly beautiful GT car, which featured a low drag roof and rear section.
It first ran in May 1962, but was sidelined since the FIA would not include the GT Class in the Sports Car World Championship.
However, a private motor dealer prepared a convertible which became Jaguar cars principal development E-Type, and was progressively modified with a lighter gauge steel body, and an engine with a wide angle head.
The result was the Lightweight E-Type Jaguar sports car and, in October 1962, work began on producing the first car which was intended to be the prototype for a short run of similar cars.
In the end, 12 factory Lightweights were built, with all but one being delivered in 1963, along with two semi-lightweight versions.
