Jaguar’s XK engine is rumored to have been developed during World War II by a group of engineers as they protected the firm’s Coventry factory during a German bombing raid. So excited about the engine’s potential, company founder Sir William Lyons is said to have begun testing the design during the war under the auspices of it having a potential military application.

The result was a masterpiece. Displacing 3.4 liters, the inline six-cylinder engine featured qualities unheard of for the time, including a high-temperature, high-strength aluminum-alloy cylinder head with hemispherical combustion chambers, inclined valves, and double overhead camshafts. Fed by twin SU carburetors, the engine produced a reported 160 horsepower. To showcase his revolutionary engine, Lyons penned an open two-seat sports model utilizing lightweight aluminum bodywork. He later named the sleek, short-wheelbase roadster the XK 120—a reference to the car’s reported top speed of 120-mph

Famously debuting at the 1948 Earl’s Court Motor Show, the car was thought by Lyons to be a limited production model. All plans changed once the public laid eyes on it. Faced with overwhelming interest, Lyons and his team quickly altered the hand-formed aluminum body to one of all steel and thrust the showstopper into production. The XK 120’s performance proved historic as its competition-bred evolution, the XK 120-C—better known as the C-Type—would go on to win the 24 Hours of Le Mans in both 1951 and 1953.

The stunning Jaguar XK 120 SE roadster offered here checks all the right boxes. Completed at Jaguar’s Browns Lane factory towards the end of 1954, the car came factory equipped with the desirable “Special Equipment” performance package, which included stronger pistons, higher-lift camshafts, and dual exhaust for a claimed 20 horsepower increase.

A left-hand drive, US-market example, this XK 120 SE roadster was reportedly treated to a full restoration in 2004 to concourse quality and is said to have covered just over 4,000 miles since. It is finished in the ultimate Jaguar color combination of British Racing Green over Biscuit tan leather upholstery with a black fabric soft-top. The car rides on chromed 48-spoke, wire wheels with two-eared Rudge-Whitworth knockoff hubs and shod in period-correct Dunlop tires. Most importantly, the accompanying Jaguar Heritage Trust Certificate confirms this car retains its numbers matching engine.

This stunning Jaguar XK 120 SE Roadster is certainly among the finest examples on the market. Well-equipped from the factory and eligible for a host of international touring events, this wonderful example will surely continue to impress its next curator and all who behold it.