The Ford GT40 is a high-performance endurance racing car with the Mk I, Mk II, and Mk III model cars being based upon the British Lola Mk6, and were designed and built in England, while the GT40 Mk IV model was designed and built entirely within the United States. The range was powered by a series of American-built engines modified for racing.
The GT40 won the 24 Hours of Le Mans four consecutive times, from 1966 to 1969 (1966 being the Mk II, 1967 the Mk IV, and 1968–1969 the oldest chassis design, the Mk I), including a 1-2-3 finish in 1966. In 1966, with Henry Ford II personally in attendance at Le Mans, the Mk II GT40 provided Ford with the first overall Le Mans victory for an American manufacturer, and the first victory for an American manufacturer at a major European race since Jimmy Murphy´s triumph with Duesenberg at the 1921 French Grand Prix. The Mk IV GT40 that won Le Mans in 1967 is the only car designed and built entirely in the United States to achieve the overall win at Le Mans.
The GT40 was originally produced to win long-distance sports car races against Ferrari (who won at Le Mans six times in a row from 1960 to 1965). Ford/Shelby chassis #P-1075, which won in 1968 and 1969, is the first car in Le Mans history to win the race more than once, using the same chassis. Using an American Ford V-8 engine, originally of 4.7-litre displacement capacity (289 cubic inches), it was later enlarged to the 4.9-litre engine (302 cubic inches), with custom designed alloy Gurney–Weslake cylinder heads.
The car was named the GT (for Grand Touring) with the 40 representing its overall height of 40 inches (1.02 m, measured at the windshield) as required by the rules. Large-displacement Ford V8 engines (4.2-litre, 4.7-litre and 7-litre) were used, compared with the Ferrari V12, which displaced 3.0 litres or 4.0 litres.
Early cars were simply named “Ford GT”. The name “GT40” was the name of Ford’s project to prepare the cars for the international endurance racing circuit, and the quest to win the 24 Hours of Le Mans. The first 12 “prototype” vehicles carried serial numbers GT-101 through GT-112. The “production” began and the subsequent cars—the MkI, MkII, MkIII, and MkV (with the exception of the MkIV, which were numbered J1-J12)—were numbered GT40P/1000 through GT40P/1145, and thus officially “GT40s”. The name of Ford’s project, and the serial numbers dispel the story that “GT40” was “only a nickname.”
The contemporary Ford GT is a modern homage to the GT40.
Information thanks to Wikipedia