The JS3 was designed in late 1970 by
Michel Têtu. Two scale models of the car were built and tested at the Eiffel wind tunnel late in January 1971 before choosing one to become the final design. Ligier chose
Cosworth to supply the engine. The JS3 did not use the four-cylinder
FVA found in the JS1 but instead got a 2993cc
DFV V8 capable of producing more than 400 bhp. This engine had already had considerable success in Formula 1, but far less success in sportscar racing.
Keith Duckworth himself felt that the DFV's
flat-plane crankshaft would limit the engine's reliability and, thus, potential success, in endurance racing events. The DFV-powered
Ford P68 and
Ford P69 designed by
Len Bailey, for example, were unsuccessful The JS3 was officially unveiled on March 15, 1971, at Automobiles Ligier's Vichy workshops. It wore the distinctive green-and-yellow livery of the car's sponsor, British Petroleum. ==Racing history==