|Jaguar Land Rover Special Operations’ new Lightweight E-type. Click to enlarge.|
Jaguar Land Rover Special Operations unveiled its new Lightweight E-type—the first recreation to come from Jaguar Heritage, which operates within the Jaguar Land Rover Special Operations division. Only 6 will be built. Car Zero has been completed and, on 14 August, will be revealed at the opening reception to the Pebble Beach Automotive weekend. Jaguar announced in May 2014 that it would recreate six new Lightweights, each built by Jaguar Heritage, part of Jaguar Land Rover’s new Special Operations division.
In recreating the Lightweight, Jaguar Heritage has drawn on Jaguar’s engineering and design resources, including the company’s aluminum body technology. The specification includes an aluminum bodyshell with doors, trunklid, hardtop and hood also in aluminum. The six-cylinder XK engine mirrors the original power units, with an aluminum block, wide-angle aluminum cylinder head and dry sump lubrication.
Each of the six cars will be built to a specification originated from the last Lightweight E-type produced in 1964 and will be hand-crafted at the original home of the E-type, Jaguar’s Browns Lane plant in Coventry, England. The cars will be sold as period competition vehicles and all will be suitable for FIA homologation for historic motorsport purposes.
The bodyshell. The core component of the Lightweight E-type is its aluminum bodyshell. This material replaced the steel of the production E-type in the quest to shed weight—some 250lb (114kg) were saved compared with the standard car.
Current advanced technology was deployed to ensure the highest quality and most faithful rendition of the Lightweight E-type’s open two-seater body components. Using state-of-the-art scanning technology, the inner and outer surfaces of a Lightweight bodyshell were digitally mapped.
The resulting massively detailed scan, which recorded dimensions and shape down to a fraction of a millimeter, was then assessed by Jaguar’s technicians to validate how the body was assembled back in the 1960s, how consistent the structure was side-to-side, and how it could be engineered today to produce the highest quality result for the Lightweight E-type project.
As this digital capturing process gave Jaguar’s engineers complete control over the Lightweight E-type body’s 230 individual components, their shapes could then be optimized before the data was sent to the tool room at Jaguar’s Whitley 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 datum, this being flipped to produce an identical condition on the opposite side.
Additionally, before being signed-off, the outer ‘A-surface’ CAD scan was transferred to Jaguar’s design department where the surface geometry was finalized. All this work ensured that the tooling from which the majority of the new body parts are produced is as accurate as possible.
Approximately 75% of the panels are made in-house at Whitley, just a few very large pressings being supplied by external specialists using Jaguar-designed tooling. The grades of aluminum used for both the under-structure and surface panels are almost identical in mechanical properties to those used for the original 1963 Lightweight E-types.
The body is completed to original Lightweight E-type Chassis no. 12 condition, by which time Jaguar had added some additional strengthening in key areas of the shell. The aluminum body is then completed by the addition of an aluminum bonnet, 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 Car Zero; this is effectively an engineering prototype and will not carry one of the six Lightweight chassis numbers.
The engine and drivetrain. The Lightweight E-type was powered by a highly developed version of Jaguar’s straight-six XK engine which, with its chain-driven twin overhead camshafts and aluminum head with hemispherical combustion chambers, remained highly advanced in 1963 even though it had first been seen in the XK 120 as far back as 1948.
This engine powered the C- and D-types to five Le Mans victories in the 1950s, and the unit developed for the Lightweight E-type is based on the 3,868cc (236 cu in) engine which, in the D-type, had won Le Mans in 1957. A similar big valve wide angle cylinder head is used, but in place of the D-type’s cast iron block, Jaguar introduced an aluminum block for the Lightweight E-type which substantially reduced the amount of weight over the front wheels. This also features in the present-day car, with pressed-in steel liners.
|Click to enlarge.|
Another major 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 in the under hood area. This eliminates oil surge during fast cornering and consequent risk of damage to the engine’s bearings, and also allows a greater quantity of oil to be carried.
The compression ratio is 10:1; today’s car is supplied with three 45DCO3 Weber carburetors. These were homologated by Jaguar for the Lightweight E-type in addition to a Lucas mechanical fuel injection system, which is being offered to customers as a cost-option (and which is fitted to Car Zero). The exhaust manifold is a steel fabrication and leads the exhaust gases into twin pipes which take them through a center silencer box to the rear of the car, where the exhaust system ends in twin polished tail pipes.
Whether carburetors or fuel injection is specified, brake horsepower is well above 300, and with torque in the region of 280 lb-ft (380 N·m) at 4500 rpm, the car is endowed with rapid acceleration from comparatively low engine revs—a traditional feature of Jaguar racing engines.
A 12-volt negative earth electrical system is used, and the engine benefits from a modern inertia-type starter motor. The water and oil radiators are in aluminum alloy, there is an aluminum expansion tank for the coolant, and the fuel tank is mesh-filled for safety.
The power is transferred to the road via a lightweight, low inertia flywheel, a single-plate clutch and a Jaguar close-ratio, manual four-speed all-synchromesh gearbox as used by the Lightweight E-type in period. A variety of final drive ratios are available, all with the Powr-Lok limited-slip differential, but a 3.31:1 ratio is supplied as standard.
Suspension, steering and brakes. The twin 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 uprated shock absorbers controlling the torsion bar springs (front) and the four coil springs (rear).
The steering is the standard E-type rack-and-pinion, with a traditional wood-rim wheel for the driver. Larger (12.25in) 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 period type in the correct perforated style, and like the originals are cast in magnesium alloy. Rim width is 7-inches front, 8-inches rear. Dunlop racing tires are fitted, 6.00 section front, 6.50 section rear, both in CR65 compound.
The monocoque bodyshell is built at Whitley where it is mated to its tubular engine sub-frame—which is stiffened with gussets as for the original Lightweight—and then shipped to Jaguar’s Gaydon facility for painting. From there it is then taken to Jaguar Heritage at Browns Lane where the car is built up with powertrain, suspension, brakes, steering, electrical items, instrument panel and soft trim.
Car Zero underwent a 15-day shake-down period at Jaguar Land Rover’s test facility at Gaydon to prove out the car’s dynamics and establish optimum suspension settings.
The E-type was produced between 1961 and 1975; just above 72,500 were built. The Lightweight E-types were built in 1963 (one car being delivered in 1964) by Jaguar’s competition department. Twelve complete cars were built in total—11 are believed to survive today.