Jaguar has revealed the prototype of its continuation Lightweight E-Type – six of which will be built and sold.
Jaguar announced in May 2014 that it would create six continuation Lightweight E-Type vehicles, each built by Jaguar Heritage, part of Jaguar Land Rover’s new Special Operations division.
Each of the six cars will be built to the specification of the last Lightweight E-Type delivered in 1964 and will be hand-crafted at a new Heritage facility located at the spiritual home of the E-Type, Browns Lane in Coventry, England. The cars will be sold as competition vehicles and all will be suitable for FIA homologation for historic motorsport purposes.
These six cars are the 'missing' six vehicles from the 'Special GT E-Type' project, which originally started in February 1963 with the objective of building 18 cars. Only 12 of the aluminum-bodied Lightweight E-Type vehicles were eventually built and the remaining six designated chassis numbers have lain dormant, until now. The six new cars will carry these unused Lightweight E-Type chassis numbers. A race winner in the hands of a variety of famous drivers during its competitive career, the car achieved worldwide fame, and today, original examples are highly sought after.
In recreating the Lightweight E-Type, Jaguar Heritage has been able to call upon the superlative skills and experience of many talented engineers and technicians currently working at the company. Many employees have historic links with the building of the original E-Type. One employee can trace three generations of service to Jaguar, dating back to the 1960s. The expertise and attention brought to bear on this project ensures the vehicles will be authentic and built to the highest quality standards.
“Operating from a brand new workshop at Browns Lane – now open for the restoration and servicing of customer cars – the building of six new, meticulously crafted Lightweight E-Type period competition cars by Jaguar Heritage is testament to the unique skills within the team. To know those same skills can also be utilized to the benefit of existing classic Jaguar owners means this is a very exciting time for Jaguar Heritage.”
Derek Weale, Director, Jaguar Heritage Business
ENGINEERING
Body
The core component of the Lightweight E-Type is its aluminum body shell, which reduced the weight by 250lbs (114kg) versus the production steel bodywork. When tasked with recreating the aluminum body, today's Jaguar engineers could relate at once to what their predecessors had achieved 50 years before. Even though enormous advances in aluminum technology have been made since the 1960s, the decision was taken not to incorporate modern materials or build methods. While high-strength aluminum alloys and bonded structures would have been invisible, they would not have been true to the original design – nor would they have conformed to the FIA’s homologation requirements for historic racing.
Advanced technology was deployed to ensure the highest quality and most faithful rendition of the Lightweight E-Type. Using advanced scanning technology, the inner and outer surfaces of a Lightweight body shell were digitally mapped. The resulting detailed scan, which recorded dimensions and shape down to a fraction of a millimeter, was assessed to validate how the body was assembled in the 1960s. This also revealed how consistent the structure was side-to-side, and how it could be engineered today to produce the highest quality results.
This digital capturing process gave engineers complete control over the body's 230 individual components. Shapes were optimized before the data was sent to the tool room at the engineering center. Even panels which are unseen within the structure have been faithfully reproduced. To ensure absolute symmetry, one side of the scanned body was used as the baseline, and then mirrored to produce an identical form on the opposite side.
The outer ‘A-surface’ CAD scan was then transferred to the design department, where the surface geometry was finalized. This work ensures that the tooling from which the body parts are produced is as accurate as possible.
Approximately 75 percent of the panels are made in-house at Jaguar Land Rover, with a few very large stampings being supplied by external specialists using Jaguar-designed tooling. The grades of aluminum used for both the under-structure and surface panels are nearly identical to those used for the original vehicles. The body is completed to original Lightweight E-Type Chassis no. 12 specifications, by which time additional strengthening in key areas of the shell had been added.
The aluminum body is then completed by the addition of an aluminum hood, doors and trunk lid. As with the original cars, an aluminum hard top is standard.
The development of the body-in-white tooling was undertaken by the same department that builds all Jaguar Land Rover prototype vehicles. The build process and assembly procedures were initially proved out on a prototype known as “Car Zero;” this is an engineering prototype and will not carry one of the six Lightweight chassis numbers.
For the Lightweight E-Type project, Jaguar engineers created a 'grey book' of the type used during the development of new production Jaguar vehicles. This internal document sets out the required quality standards in terms of body shell fit-and-finish and ensures a consistency of build quality for all six new Lightweight E-Type vehicles.
A roll cage is standard equipment and the body includes mounting points for a detachable front extension which is available as an option. The cars are built in a form suitable for FIA homologation for historic motorsport purposes.
Powertrain
The Lightweight E-Type was powered by a highly tuned version of the Jaguar XK inline-six engine. With chain-driven dual overhead camshafts and an aluminum head with hemispherical combustion chambers, it remained an advanced design in 1963 even though it was introduced in 1948 in the Jaguar XK 120.
This was this engine that powered the C-Type and D-Type vehicles to five Le Mans victories in the 1950s. The unit developed for the Lightweight E-Type is based on the 3,868cc (236 cu in) engine which won Le Mans in 1957 in the D-Type. A similar cylinder head is used, but in place of the D-Type's cast iron block, Jaguar introduced an aluminum block with steel liners for the Lightweight E-Type, which substantially reduced the amount of weight over the front wheels.
Another feature transferred from the D-Type is the dry sump lubrication system. This uses a scavenge pump to collect oil from the sump and return it to a separate oil tank. This reduces oil windage, maintains oil pressure during fast cornering and allows for higher oil capacity.
The compression ratio is 10:1 and the car is equipped with three 45 DCOE carburetors. These were homologated for the Lightweight E-Type alongside a mechanical fuel injection system. This fuel injection system is being offered to customers as an option, and is fitted to prototype “Car Zero.” The exhaust manifold is a steel fabrication that leads into dual exhaust pipes and a center muffler at the rear of the car, later terminating in two polished tail pipes.
With over 300 horsepower and torque in the region of 280 lb-ft at 4500 rpm, the car is endowed with rapid acceleration from a comparatively low engine speed – a traditional feature of Jaguar racing engines. A 12 volt negative ground electrical system is used, and the engine benefits from a modern inertia-type starter motor. Other aluminum features include the radiator, oil cooler and expansion tank for the coolant.
The power is transferred to the road via a lightweight, low inertia flywheel, a single-plate clutch, and a close-ratio, four-speed, fully-synchronized manual gearbox. The standard rear axle ratio is 3.31:1 and a variety of final drive ratios will be available. All Lightweight E-Type vehicles will be delivered with the Powr-Lok limited-slip differential.
Chassis
The double wishbone front suspension and independent wide-based wishbone rear suspension (where the drive-shaft serves as the upper link) are set up according to period racing practice, with upgraded shock absorbers controlling the front torsion bars and rear coil springs.
The steering is the standard E-Type rack-and-pinion, with a traditional wood-rim wheel for the driver. Larger (12.25-inch) brake discs are fitted at the front, with the rear brakes being standard E-Type. No servo is fitted.
The 15-inch diameter wheels are the period correct 'perforated' style, and cast in magnesium alloy. Rim width is 7-inches in front, and 8-inches in the rear. Dunlop racing tires are fitted – 6.00 section front, 6.50 section rear, both in CR65 compound.
Final assembly
The unibody is built at the JLR facility in Whitley, England where it is mated to its tubular engine sub-frame – which is stiffened with gussets as it was on the original Lightweight – and then shipped to the JLR Gaydon facility for painting. It is then taken to Jaguar Heritage facility at Browns Lane where the car receives its’ powertrain, suspension, brakes, steering, electrical items, instrument panel and soft trim. This process takes place in a dedicated work area close to where the original Lightweight E-Type vehicles were assembled.
It is at this stage that personal consultation with the customer dictates the final specification for each car – no two of which are expected to be identical.
Prototype “Car Zero” underwent a rigorous shake-down period at our test facility at Gaydon, England. This test included a vigorous shakedown at the hands of Mike Cross, Jaguar Chief Engineer, Vehicle Integrity. Each of the six new Lightweights will go through similar tests to ensure that they meet the required standards in terms of braking, handling and steering.
“In our contemporary Jaguar sports cars our aim is always to achieve an immediacy of response to all driver inputs – and the goal with Lightweight E-Type was the same. For me, its response to steering, brake and throttle inputs – along with the terrific noise it creates – is what makes it such an engaging machine from the driver’s seat.”
Mike Cross, Chief Engineer, Vehicle Integrity, Jaguar
Source: Jaguar