The Jaguar V12 engine is a V12 internal combustion engine produced by Jaguar Cars. The engine was based on a prototype design by Claude Baily for an intended Le Mans car—the Jaguar XJ13. The XJ13 project was terminated in 1966 before the car was ever entered into competition, but under the direction of Jaguar Chief Engineer William Heynes the V12 engine design was reworked by engineers Walter Hassan and Harry Mundy into a production-ready version, first installed in the Series 3 Jaguar E-Type of 1971. The V12 was the second production engine design in Jaguar's history. The all-aluminium block was fitted with removable wet iron liners, complete with single overhead camshaft aluminium heads with two valves per cylinder. It was regarded as one of the premier power plants of the 1970s and 1980