Jaguar's V12 was one of the premiere power plants of the 1970s and 1980s. It was a V12 piston engine, originally designed for a Le Mans car, the ill-fated Jaguar XJ13. The V12 was only Jaguar's second engine design in the history of the company. It had a SOHC 2-valve head with flat combustion chambers.
The original 5.3 L (5343 cc) version had an under square 90mm bore and 70mm stroke and produced 240kW and 420Nm.
This version was used in the following cars:
1975-1981 Jaguar XJS
1972-1981 Jaguar XJ12 (Series 1 and 2)
Jaguar V12 engine and gearbox. Early Carburettor version
A High-Efficiency 5.3 HE debuted in 1982. Although power was down somewhat, fuel economy was up by nearly 50%.
The 5.3 HE was used in these cars:
1982 Jaguar XJ12 (Series 3)
1982-1992 Jaguar XJS
The engine was stroked to 78.5mm in 1989 for a displacement of 6.0 L (5994 cc) to bring back some of the power lost to emissions requirements.
The 6.0 HE was used in the following cars:
6 litre fuel injected Jaguar V12 in situ
1994-1995 Jaguar XJS
1994-1995 Jaguar XJSC
Jaguar XJ12 (XJ40)
1994-1996 Jaguar XJ12 (X300)