In the postwar era, Jaguar's people, from the top down, demonstrated a drive, a fervor to get going again, that was not present in the rest of the struggling industry. Materials were short, power was expensive and petrol was hard to get, but Jaguar had big plans, including a new engine, a new sedan, a new sports car and a new race car.
The XK engine, as it came to be called, started out as a four-cylinder dohc design, not a six. It was an engineering collaboration between racers and engineers, the team including longtime engineering boss Bill Heynes, racer Wally Hassan, engineer Claude Baily, driver-builder Dick Oats and the now famous Harry Weslake.
In September 1948, a finished version of the 2.0-liter four-cylinder Jag engine, installed in a streamliner built especially for the stunt, ran across a section of Belgian autoroute in Jabbeke at a speed in excess of 176 mph without the other two cylinders.
A few days later, on October 1, Jaguar announced the Mark Five sedan and drophead coupe, with full hydraulic brakes and independent front suspension, in either 2.7- or 3.5-liter versions. And a few days after that, Jaguar showed a car that would live forever, the brand-new XK 120 with its dohc six-cylinder. It was nothing short of sensational. The car was shown in the U.S. for the first time at the New York Auto Show in early 1949, under the watchful eye of legendary importer Max Hoffman, who had the Jaguar franchise. Another sensational introduction on foreign soil assured Sir William Lyons and his staff that the sports car was on its way.
Late in May 1949, with the success in New York still reverberating, Jaguar ran the car privately on yet another section of Belgian motorway and easily exceeded 120 mph in completely stock trim. In fact, it exceeded 130 mph! A planeload of British, ink-stained wretches from The Motor and Autocar and the London and provincial papers was flown over to watch the car do 120 officially. A plot was hatched to race the car for the first time ever at a 1-hour sprint at Silverstone in August of 1949.
Team Jaguar showed up with one red car, one white car and one blue car, the colors of the British flag, for the first postwar production car race in England: Leslie Johnson finished first in the white car, Peter Walker second in the red car and Prince Birabongse of Thailand (racing name, B. Bira) taking a DNF after a shunt and a blown tire. First and second, first time out!
The first time a Jaguar XK 120 came to America to race was in January 1950, when Leslie Johnson led a contingent of three cars to the SCCA race in Palm Beach, Fla., shortly after New Year's Day. In rain and high winds, the Jaguar finished fourth in a race that included three giants of American sports-car racing-Briggs Cunningham in a Cadillac-Healey, second; Phil Walters in a Healey, fifth; and Miles Collier in a Riley-Ford, sixth. Sam Collier finished eighth in one of the XK 120s, and Bill Spear DNF'ed with no brakes in the third car. All the drivers agreed the fitted drum brakes were not optimal and that something should be done about them.
Jacked up by its initial good showings in Britain and America, Jaguar financed a five-car team for the 1950 Mille Miglia, but only one of the five cars, Leslie Johnson's, had a good result, a fifth place. The engineers were quickly finding the weak spots in the XK 120 and fixing them, including rear springs, connecting rods and, of course, weak brakes. The racing program, and everything at Jaguar, was complicated in 1950 by the move from Swallow Road to the new million-sq-ft facility at Brown's Lane, which, in completely redone form, is still in use today as a Jaguar production site.
An XK 120 finally won a race outside Britain when a privateer, Alfonso Mena, slaughtered the weak competition in a race in Cuba in February 1950. But shooting fish in a barrel was not the British idea of open competition. Le Mans was. So three fresh cars went to The Big Race in 1950, only to be trounced by Briggs Cunningham's Cadillacs. Leslie Johnson ran as high as second during the middle portion of the race, but, in order to save brake wear, he kept downshifting the transmission at high speeds and eventually blew the clutch, which prompted the substitution of a solid-disc clutch plate from then on.
Two months went by and Jaguar loaned out Tommy Wisdom's Mille Miglia race car to run in the most famous race in Ireland, the Tourist Trophy event that ran between Belfast and Lough Neagh through the green hills and dales. In pouring rain, the new driver hung it all the way out and won. His name was Stirling Moss, and shortly after the TT victory Moss and Johnson did a pre-Le Mans 24-hour test at the Montlhery circuit in France in Johnson's race car.
And, to top off what was already a landmark year in the history of Jaguar racing, another young racer, operating out of International Motors in Hollywood, Calif., won the prestigious sports-car race at Pebble Beach in November, the first Jaguar victory on American soil by an American driver. That man was Phil Hill.
To end the year, Jaguar took another new car, the Mark Seven sedan, to the London Motor Show and to a reception at the Waldorf-Astoria in New York.
All of this success in the salesrooms and on the race, rally, cross-country and endurance courses of Europe and America was prelude to the introduction of the XK 120C or C-Type, Jaguar's first, pure race machine of the postwar era, in 1951.