1961 Jaguar XK150

The Jaguar XK150 was introduced a decade after the arrival of its predecessor, the XK120, yet retained a strong family resemblance on the outside while embracing tremendous mechanical changes underneath. The XK140 that was built between the XK120 and XK150, was a transitional model, while the XK150 was a thorough updating of the XK look with a styling progression that moved Jaguar from the 1940s into the 1960s. The small glass area of the previous cars was greatly enlarged for improved visibility and modernized with a one-piece wraparound windshield design. The slab-sided body and thin doors were very modern, and the interior room and comfort were dramatically increased. For the first time, larger real roll-up glass windows were used, and Jaguar's Le Mans boot badge was updated with an ever-growing list of victories. The interior did away with the previous high-maintenance wood veneer, opting instead for an entirely new roadster-style aluminum and padded leather dash. Front-wheel disc brakes were standard on all XK150s, a big improvement over the previous drum brakes, which would experience 'fade' following repeated stops from high speed. With the disc brakes installed, the XK had stopping power to match its prodigious straight-line speed.

The Jaguar XK150 was announced in its home market in May 1957 and production would continue through 1961, with 9,382 examples built during that time. The much-admired chromed Jaguar mascot was made available as an optional extra on an XK for the first time.

Mechanical Specification
The X-frame chassis had a 102-inch wheelbase, an overall length of 177 inches, and was 62.2 inches wide. Although it used the same basic chassis as its predecessor, its body was wider and although it used many XK120/140 pressings, the increase was achieved by means of a 4-inch wider central fillet. A higher front wing line and broader radiator grille were other visual differences.

The suspension and chassis were similar to the XK140, with an independent front setup with wishbones and a torsion bar, while the rear relied on a live axle with half-elliptic leaf springs. Steering was via a manual-only rack and pinion system. In 1960, four-wheel Dunlop 12-inch disc brakes became optional. Factory specification 6.00 × 16 inch Dunlop Road Speed tires or optional 185VR16 Pirelli Cinturato CA67 radials could be installed on either 16 × 5K½ solid wheels or optional 16 × 5K wire wheels.

XK Engine
The William Heynes designed 3.4-litre Jaguar XK double overhead camshaft inline-6 engine was similar to the XK140's, but with a new 'B' type cylinder head that boosted output to 180 (SAE) bhp at 5,750 RPM. It had double SU HD65 carburetors and the bore measured 83 mm and the stroke of 106mm.

A fire at the factory in February 1957 caused a twelve-month delay of special equipment models with the more potent SE engine and disc brakes. Upgrades included a modified B-Type cylinder head with larger exhaust valves and twin 1.75-inch SU HD6 carburetors which helped increase output to 210 (SAE) BHP at 5,500 RPM and, even more noticeably, an 11% increase in torque. Most of the export cars received the SE improvements.

The open two-seater could also be purchased with an 'S' engine which had three 2-inch SU HD8 carburetors and a straight-port cylinder head, bringing output to 250 (SAE) bhp.

In 1960, engineers took the 3.8-liter engine from the full-sized luxury Mark IX saloon and placed it into the bay of the XK150. This optional engine delivered 220 bhp in standard guise and 265 bhp in 'S' models.

Overdrive and a Borg-Warner automatic gearbox were the transmission options, the latter becoming an increasingly popular choice, while a Thornton Powr-Lok limited-slip differential was available for the XK150 'S'.

Body Styles
Body styles included a fixed head coupe (FHC) and a drophead coupe (DHC), with a roadster version arriving the following year, in 1958. The Drophead coupes had a neater rear decklid than previous examples, along with unique chromed rain gutters and the convertible top had been styled to work harmoniously with the XK150's lines. It sealed tight to repeal water but could also fold swiftly into a compact, well-engineered bustle, complete with a tonneau.

Production
By the time production ceased in October of 1960, a total of 9,382 examples of the XK150 had been built. The most popular was the fixed head coup with 4,445 units built, followed by 2,672 of the drophead coupe and 2,265 of the roadster.

The XK150 was the final glorious incarnation of Jaguar's fabulous 'XK' series of sports cars.

by Daniel Vaughan | Jun 2023