XK120 Timeless founder of a sporting dynasty

AutoTrader NZ
Published 9 March 2020

The two cars, the Super Sports (which became the XK120 two-seat roadster), and the Mark VII both used the same engine, a 3.4-litre double overhead camshaft six-cylinder.
The motor had a seven-bearing crankshaft and in the XK120 developed 160bhp.

Jaguar had planned to build 200, but public interest was so great that the sports car went into full-scale production.

It had a sleek body that is as ageless as its descendent the E-Type’s; spats smoothed the airflow over the rear wheels.

Export markets were supplied from mid-1949, and British buyers had to wait until 1951 to get their hands on this revolutionary sports car that blended a competitive price with outstanding performance.

Motor magazine clocked its test XK at 125mph (around 200km/h), and a version with an aerodynamic undertray went 132.6mph in a test run on a Belgian motorway.

More usually the XK120’s top speed was a genuine 120mph, which made it the world’s fastest production car at that time. Acceleration was equally impressive: 0-96km/h took 10 seconds and the car would reach 160km/h in a shade over 35 seconds. Average fuel economy was 22 miles per gallon.

Original cars had hand-built aluminium-bodies but tooling for steel-bodied cars was in place by 1950.

Jaguar raced the car from the outset, and XK120s took the first three places in the 1949 production car race on the ultra-fast Silverstone track in England.

Ian Appleyard drove one to victory in the Alpine Rally, and the legendary Stirling Moss won the Tourist Trophy in an XK.

A fixed-head coupe version (our cover car) arrived in 1951, followed by a droptop coupe two years later.

The XK120 had a separate chassis, twin SU carburettors, and a four-speed Moss gearbox with synchromesh on the upper three ratios.

Front suspension was by wishbones and torsions bars, and the solid rear axle rode on semi-elliptic springs.

The standard wheels were steel, though wire wheels were a popular option. Brakes were 12-inch diameter drums.
In 1954, the 120 was replaced by the similar-looking XK140 with 190bhp motor, laying the foundations for the elegant XK150 of 1957 and the most desirable of all Jaguar sports cars, the E-Type of 1961.

Like the E-Type, the XK is an ageless design, a superb and ground-breaking vehicle that paved the way for some of the world’s most desirable sports cars.