A FEW LESS-KNOWN FACTS ABOUT THE JAGUAR XK ENGINE

Early variations of the XK and other experimental Jaguar engines were probably test running as early as 1943, during the Second World War. Prior to the war, SS cars, as Jaguar was then known, had used engines supplied by the Standard Motor Company. They were a 1.5-litre four-cylinder and two six-cylinder engines of 2.5 and 3.5 litres. After the war, Jaguar boss William Lyons, together with William Heynes, Claude Baily, and Walter Hassan, sought to develop a range of new engines for the cars, designed to stay ahead of the opposition for some years. A range of engine types was considered, and different types of valve operation experimented with. XG four: 1776cc, using Standard engine with crossover pushrods similar to BMW 328 engines XF four: 1732cc with twin cams and run in 1942 XK1: the first of four Heynes engines of 1790cc XK2, 3, and 4: 1790cc, developed from 1946 –1947 Engine of 1970cc used in the MG land-speed record breaker of Goldie Gardner in 1948 XK1 and 2 had a three-bearing crankshaft and XK5 had a five-bearing crankshaft. By 1947, a 3.2 litre six-cylinder was being experimented with. It was then stroked to 3442cc, and became the production engine size in 1947–48. A four-cylinder XK unit was also kept in development alongside the sixes until 1953. In 1951, a 1986cc six-cylinder XK was developed, and by 1954 this had been stretched to 2483cc to power the new Jaguar compact, the Mark I, as a short block version of the larger XK engine, later expanding into 2.8 litres for the new XJ6 sedan, along with alloy block race versions of the engines . Powerful and reliable even under extreme race conditions, the XK six engine in 4.2-litre guise soldiered on in the XJ6 sedan until 1986 and in the Daimler DS420 Limousine until 1991. The XK engine also saw use in some British armoured vehicles and in low-production race and road cars, and it remained one of the longest serving power plants in the world for some six decades.