Jaguar XK 120 Roadster

Jaguar XK 120 OTS

Initially produced as roadster only, the XK120 featured a split windscreen, cut-down

doors, canvas roof and detachable sidescreens. When removed, the roof and side screens

were stored behind the seats.

There were no exterior door handles; entry was made via a pull-cord. When the top and

sidescreens were

on, the pull-cords were accessed through a flap in the sidescreens.

With intentions of making just a few hundred cars, the first run of Jaguar XK120's

were aluminum-bodied, but overwhelming demand quickly prompted the switch to pressed

steel. In May 1950, the first predominantly steel bodied XK120 rolled off the

production line. Only the hood, doors and trunk remained aluminium.

Chassis and Suspension

Borrowed from Jaguar's big sedans, the modified frame was actually sturdier than needed, making

the XK heavier than other sports cars of the day. Riding on 16" x 6" tires, the

chassis featured torsion-bar independent front suspension with ball joints, and semi-elliptic leaf

springs in the rear. The car was narrow, tracking 51 inches at the front and 50 inches in the rear.

DOHC Motor

Described by many as "jewel-like", the dual overhead cam motor was built under direction

of William Heynes. The under-square 3.4 litre size was derived by an 83 mm bore by 106 mm stroke.

Underneath the polished valve covers were a pair of chain-driven camshafts, which sat atop

an aluminum-alloy head. Hemispherical-shaped combustion chambers allowed

use of larger valves. Induction was supplied by a pair of SU H6 sidedraft carburetors.

When fitted with domed cast-aluminum pistons, engine compression ratio

was 8.0:1. In this configuration, peak output was 160 horsepower with

195 lb/fts of torque. For some markets, the compression ratio was dropped to 7.0:1. This was

due to the fact that only 70 octane fuel was available in some post WW2 countries.