1951 Jaguar XK120

The Jaguar XK120 was conceived and constructed three months prior to its debut in 1948 at the Earls Court Motor Show where its stunning appearance caused such a sensation that it took Jaguar by surprise. The resulting demand for what was then the world's fastest production cars convinced Sir William Lyons and the team at Holbrook Lane, Coventry (through 1951, then Browns Lane, Coventry from 1951 to 1954) to put it into production.

The XK120 was the work of Jaguar boss William Lyons himself and one of the most elegant shapes to ever grace a motor car. It was produced from 1948 to 1954 and was their first sports car since the SS100 which ceased production in 1940. Initially built with roadster bodywork, the '120' in its name referenced its top speed which made the XK120 the world's fastest standard production car at the time of its launch. The roadster body was joined by a coupe in 1951, and then a drophead coupe in 1953.

The XK120 had been conceived as a coachbuilt, aluminum paneled structure as Jaguar did not anticipate selling more than 200 examples in its inaugural year. With demand quickly outpacing that initial 200 figure, Jaguar worked with the Pressed Steel Fisher Company for the fabrication of a new all-steel paneled body, which retained the appearance of the coachbuilt original while differing in minor external details. The first 242 cars were open 2-seater bodies with aluminum panels, while subsequent production used 1 cwt or 112 lb heavier all-steel bodies. Beneath the skin, the steel car was entirely different and it would take approximately twenty months of development before manufacture could begin.

Powering the XK120 was the XK engine which had been developed during the war and intended for Jaguar's forthcoming Mark VII saloon. The 3.4-liter straight-six used double overhead camshafts, hemispherical combustion chambers, a high-strength aluminum-alloy cylinder head, seven main bearings, inclined valves, and twin side-draft SU carburetors. With the standard compression ratio of 8:1, the engine offered 160 horsepower. The 7:1 lower compression version with less performance was reserved for the United Kingdom market, where the post-war austerity measures restricted buyers to 70 octane 'Pool petrol.' The XK engine was later modified into a 3.8 liter and 4.liter version, surviving into the late 1980s.

Jaguar essentially shortened the chassis of the simultaneously announced Mark V saloon and incorporated William Heynes' torsion bar independent front suspension. There were semi-elliptic leaf springs in the rear, recirculating ball steering, 12-inch drum brakes, and a telescopically adjustable steering column. The drum brakes had a tendency to fade, so some examples received Alfin (ALuminium FINned) brake drums to rectify this problem.

The first 242 production examples of the XK120 were hand-built with aluminum bodies on ash framing with a steel chassis similar to the Mark V. These early examples were built from late 1948 through early 1950. As demand increased and beginning with the 1950 model year, all subsequent XK120 models received the pressed-steel bodies, but with aluminum hood, boot lid, and doors. The fixed head coupe (FHC) and drophead coupe (DHC) were better equipped and more luxurious than the open roadster, with wood veneer on the dashboard and interior door caps (the roadsters had leather-trimmed door caps), and wind-up windows. The detachable side screens and lightweight canvas top of the roadster could be stowed behind the seats when not in use. The roadster was devoid of external door handles, with access from the interior provided by a pull-cord accessed through a flap in the side screens when in place. Aero screens could be installed in place of the windscreen.

All body styles wore removable spats, known in the United States as 'fender skirts,' which covered the rear wheel arches and added to the vehicle's streamlined appearance. The exception was the optional center-lock wire wheels, becoming available from 1951 forwards, and when installed, the spats were omitted due to insufficient clearance for the chromed, two-eared Rudge-Whitworth knockoff hubs. The standard setup was 6.00x16-inch ply tires on 16x5K solid wheels for pre-1951 cars. 185VR16 Pirelli Cinturato radial tires were optional later in the development cycle, and chromium-plated wire wheels were optional from 1953.

The drophead coupe body style had roll-up windows with opening quarter lights, a flat glass two-piece windscreen installed in a steel-painted (body color) frame that was integrated with the body. The lined canvas top was padded and could fold onto the rear deck behind the seats when retracted.

The Special Equipment (SE) option (in the United States, it was called the M Version for Modified) added a dual exhaust system, stiffer suspension, higher lift camshafts, and 180 horsepower at 5,300 RPM. The SE option was optional beginning in mid-1951 per Service Bulletin number 95 dated June 1951.

Jaguar quickly demonstrated the capability of the XK120, showcasing its claimed top speed was no idle boast in May of 1949 by driving a roadster with its hood and side screen in place to a recorded speed of 126.448 mph on the Jabbeke to Aeltre autoroute. With the hood and windscreen detached and an under-tray fitted, the XK120 reached 132.596 mph. The car was chassis number 670002, the second XK120 built. It was finished in white, had a left-hand drive configuration, and was intended to be driven by development engineer Walter Hassan. After falling ill, driving duties were assigned to Jaguar test-driver Ron 'Soapy' Sutton.

In 1950, Leslie Johnson and Stirling Moss drove JWK 651 at the Autodrome de Montlhéry where it averaged over 100 mph for 24 hours, making it the first production car to had an average above 100 mph for 24 hours. During those twenty-four hours, there were driver changes every three hours, the best lap was 126.2 mph, the average was 107.46 mph, and it covered 2,579.16 miles. A year later, Johnson drove JWK 651 at Montlhéry with an average speed of 131.83 mph for one hour.

Along with performance, the XK120 established new standards of comfort and road-holding for a British sports car, while maintaining an attractive price. Production continued through 1954 and would prove to be the most popular of the XK series with 12,045 examples built. Of those, 7,606 were roadsters (open two-seater with 6,436 in left-hand configuration), 2,672 fixed-head coupes (2,477 with LHD), and 1,767 Drop heads (1,472 LHD).

by Dan Vaughan

Hardtop Coupe
Chassis number: 679002

This important XK120 is the first left-hand-drive Fixed Head Coupe and was the 1951 Geneva Show car. Jaguar used this car for publicity shots for the official launch of the Coupe. One of two prototypes, the car was converted from an XK120 Roadster in Jaguar's experimental department. After Geneva, the car was purchased by Captain J. Arthur, a US serviceman stationed in Germany. The car was delivered to Los Angeles in 1952 and remained in the United States for 40 years before being discovered by Australian engineer Percy Dixon. The car returned to the United Kingdom 62 years to the exact day it left, to be restored by Jaguar specialists JD Classics. This car has a number of unique features, including Mark V sidelights, a unique dashboard and a 'flower rain' on the rear shelf as well as numerous chassis and body modifications not found on the production cars but seen on the prototype XiK120 roadsters on which this car is thought to have been based.

XK120 LT2 Racer

The Jaguar XK120 LT2, also known as the Silverstone, was the factory works lightweight version of the XK 120 constructed with a one-piece magnesium body.

A few lightweight Jaguar XK120s were constructed; around 240 or 242 examples were built with alloy bodies, and were intended for competition.

There were two (some sources say 3) examples of the LT2 constructed; they were intended for competition at the 1951 LeMans 24 Hours race in the event that the XK120C was not ready in time for competition. The C-Types were ready and time and went on to win the race.

This example is a Jaguar XK120 LT2 2-seater racer. It is seen here at the 2006 Pebble Beach Concours d'Elegance.

Roadster
Chassis number: 660792

Chassis number 660792 was completed on May 3rd of 1951, and left for Brysons, Melbourne, Australia, on June 12th of 1951. The vehicle was first registered in Victoria in 1951 and then it changed hands several times in the late 1950s and 60s eventually ending up in the collection of Mark Tucakovic of Wallington, Australia, in 1973. In 1992, auto designer Karl Robertson bought the car and took it with him to Frankfurt, Germany. He completed a full restoration of the all numbers-matching car, including fitting it with the twin Brooklands screens and a Quick Type Fuel Fill to match the original 1950 LeMans team cars. The vehicle is also equipped with rare Don Busch Turbo Vent wheels of which only ten sets were produced for Australian race vehicles.

Mr. Robertson moved to the U.S. where he showed it extensively at various Concours and charity events until its sale to the current owners in 2008. The vehicle was raced extensively and the current owner performed a full refresh in 2010.

The XK120 was launched as a roadster at the 1948 London Motor Show and caused such a sensation it was quickly put into production. It earned much success competing on road-racing circuits and was Jaguar's first sports car since the SS100 which ended production in 1940.

The '120' referred to its 120 mph top speed, which made the XK120 the world's fastest standard production car at the time. With alloy cylinder heads and twin side-draft carburetors, the dual overhead cam 3.4 L straight six was comparatively advanced for a mass-produced unit of the time. It is also equipped with the rare Don Busch Turbo Vent wheels, of which only 10 sets were ever built for Australian race vehicles.

Roadster

The XK120 debuted at the 1948 London Auto Show at Earl's Court. With its full-width streamlined body and exotic mechanicals, the XK simply reset expectations for sports car enthusiasts of the time. Sir William Lyons had

sent notice that Jaguar was a force to be reckoned with, and they were, for years to come.

The XK engine is a dual overhead cam 3.4 liter, straight six, with an alloy cylinder head and twin SU carburetors. It developed 160 horsepower and helped the XK120 reach an advertised 120 MPH. It was among the most powerful sports cars of the day and sold for a very reasonable $3,000.

Hardtop Coupe
Chassis number: 860010

The first XK120 with its iconic William Lyons-designed body was first seen in 1949, and the XK line continued with the XK140 and XK150 models, until the E-Type's arrival in 1961.

This very significant Jaguar was retained by Jaguar itself for the first four years of its life, serving first as a press testing vehicle and later as a development test vehicle, and it is believed to be the lost vehicle from the batch of three cars built for the launch of the Jaguar E-Type in 1961. Perhaps most notably, it was used for high-speed testing by Norman Dewis, Jaguar's chief competition test driver. Belgian racing great and motoring journalist Paul Frere also tested the car at speed, recording 256 km/h on the Autostrada and writing about it. In the course of testing, the car was fitted with many technical enhancements and modifications, some of which made it into production and some of which did not, but many of which are still evident on this vehicle. For example, as with all of the early E-Types, it has a flat floor - but only the passenger side; the driver's side has a dropped floor as implemented on later production E-Types. It was also fitted with an interior bonnet release. In November 1963, Jaguar sold this car to Cooms of Guildford, which sold it to Bruce Buckley of Hampshire. Finished in Opalescent Dark Green with a Suede Green interior, it has been very carefully restored over a period of six years.

Roadster
Chassis number: 660881
Engine number: W3131-8

This Jaguar XK120 Roadster was built near the end of August 1951 with right-hand drive configuration. Destined for the U.S. market, it was supplied through the East Coast distributor Hoffman of New York to Sport Car Inc of Bryn Mawr, Pennsylvania, on November 12, 1951. It wore cream paintwork with a fawn top and a biscuit and red interior. By 1970, the car was owned by Kurt Rappold of Chester, PA, and purchased by Thomas Hendricks in August 1971. The car remained with Mr. Rappold for fifty-one years.

by Dan Vaughan

Roadster

Introduced in 1948 at the Earl's Court Motor Show, the XK 120 was powered by an inline six-cylinder, 3.4-liter engine paired to a four-speed manual gearbox. With 160 horsepower on tap, the XK120 was capable of achieving a sustained 120 miles per hour without breaking a sweat.

by Dan Vaughan

The Jaguar XK120 was designed to be a prestigious vehicle and produced in low numbers. The designation '120' represented the vehicle's top speed of 120 miles-per-hour. At the time, it was the fastest production car in the world.

The British automotive industry was greatly influenced by World War II. Many manufacturers went out of business due to the lack of funds, fuel and supply shortages, or their factories had been destroyed during the war. In order to stay in business, a solid production line was required that could compete with its class of vehicles. William Lyons, the owner of Jaguar, did so by creating a new class - one that was faster, more reliable, stylish, and cheaper than any other vehicle on the market.

To gain industry recognition, Lyons knew that he needed a show car that was revolutionary and bold. Lyons handled the styling while his chief engineer, William Heynes, was tasked with designing the mechanical components. When the vehicle was displayed at Earls Court, the reaction was overwhelming. Originally, Lyons planned to make between 100 and 200 examples. After the public reaction to the car and to keep up with demand, he decided to change the body from hand-formed aluminum to all-steel construction.

The body of the car was reminiscent of the 'French Curves' produced by manufacturers such as Bugatti and Delahaye of the early 1930's and 1940's. They were created in three different body styles, roadster, fixed head, and drop head (convertible).

The vehicle was powered by a 160 horsepower, 3.4 liter, inline-six-cylinder engine. Peak horsepower was achieved at 5000 RPM. The 120-mph was the promised speed, the top speed of the vehicle was around 126-132 mph depending on the trim of the vehicle.

The vehicle was designed as a touring car. However, many of the vehicles were raced. Their main weaknesses were their drum brakes which wore quickly, and their steering which was heavy and less responsive when compared to other purpose-built racing vehicles.

In 1951, Jaguar entered the grueling 24-hour of Le Mans endurance race. Three XK120C, the 'C' representing 'competition', was entered. One of the three entrants won the event.

In 1952, an XK120 was driven continuously for seven days and nights around a track located in Montlhery, France. After more than 16,000 miles in one week, the vehicle once again proved its endurance capabilities.

In 1954 production ceased. Over 12,000 examples were produced.

by Dan Vaughan