Jaguar's XJ13 is one of the great 'what ifs' of motorsport. Originally envisaged in the early 60s, the mid-engined V12 machine was intended to reassert the marque's Le Mans dominance, but corporate cold feet meant that by the time a prototype was built in 1966 it was too late.
Its quad-cam, 5.0-litre V12 was practically two six-cylinder XK engines sharing a common crankshaft and an aluminium cylinder block. Both it and the car's five-speed manual transmission were structurally integral in their midship placement, and were surrounded by a swooping Malcolm Sayer-designed aluminium body. In both its engineering and aesthetics it was a thing of beauty but, aside from an unofficial Mira lap record - albeit one which stood for 32 years - the XJ13 never got the chance to prove itself.
Now, though, Ecurie Ecosse is looking to rewrite the car's history, imagining the XJ13 as if its full potential had been realised. To ensure as authentic an end product as possible, the design and engineering team had to adhere to period regulations, with their finished machine - dubbed the LM69 - only allowed to sport design details and technology which entered motorsport no later than early 1969.
To that end, the LM69 features bodywork developed to an all-new design, while remaining "true in spirit and sympathetic to the style of the fabulous XJ13." Composite materials have been used where appropriate, as would have been the case had the original car ever been prepared for genuine competition use, while wider wheels and tyres have also been fitted.
The quad-cam V12 is said to be "much improved", too, having been designed to evoke the experience of driving at Le Mans in 1969. Remaining "of the period" and "inspired by the basic architecture of those engines which powered cars to victory in the late 1960s" it will use traditional distributors and mechanical fuel injection as standard, though clients will be offered the option of fully programmable fuel injection and ignition for improved efficiency and tuneability. Two capacities will be offered, a "standard" 1966 5.0 - 5.3 litre version, and a larger 7.3-litre alternative that uses the same basic architecture, albeit bored and stroked.
Only 25 LM69s will be produced, in keeping with the 1969 FIA homologation requirements, with each one being individually hand-built in the West Midlands. All cars will be fully road-legal, although whether they'll be eligible for entry into historic motorsport events such as Goodwood Revival, we'll have to wait and see. The Ecurie Ecosse LM69 will be officially launched at the International Concours of Elegance at Hampton Court Palace in London on September 6th - we're certainly looking forward to seeing it in the metal for ourselves.