Jaguar V12 engine

Jaguar V12 engine
5.3 L (5,344 cc) in a Jaguar XJS
Overview
Manufacturer	Jaguar Cars
Production	1971–1997 (161,583 units)
Layout
Configuration	Naturally aspirated 60° V12
Displacement	5.3 L (5,344 cc) 6.0 L (5,993 cc) 7.0 L (6,995 cc)
Cylinder bore	90 mm (3.54 in) 94 mm (3.7 in)
Piston stroke	70 mm (2.76 in) 78.5 mm (3.09 in) 84 mm (3.31 in)
Cylinder block material	aluminium, with cast-iron cylinder liners
Cylinder head material	aluminium
Valvetrain	SOHC
Compression ratio	7.8:1 – 12.5:1
RPM range
Max. engine speed	6,500
Combustion
Fuel system	4 side draft Zenith-Stromberg carburettors Lucas fuel injection
Fuel type	Petrol
Oil system	wet sump
Cooling system	Water-cooled
Output
Power output	242–750 hp (180–559 kW; 245–760 PS)
Torque output	295–580 lb⋅ft (400–786 N⋅m)
Chronology
Successor	Jaguar AJ-V8

An evolution of the 1964 DOHC prototype “XJ13” engine, the Jaguar V12 engine is a family of SOHC internal combustion V12 engines with a common block design, that were mass-produced by Jaguar Cars for a quarter of a century, from 1971 to 1997, mostly as 5.3‑litres, but later also as 6‑litres, and 7‑litre versions that were deployed in racing. Except for a few low-volume exotic sports car makers, Jaguar's V12 engine was the world's first V12 engine in mass-production. For 17 years, Jaguar was the only company in the world consistently producing luxury four-door saloons with a V12 engine.^[1][2] The V12 powered all three series of the original Jaguar XJ luxury saloons, as well as its second generation XJ40 and X305 successors.

Originally fitted with carburettors, the SOHC V12s received electronic fuel injection in 1975. In 1981, the engines were improved with higher efficiency (HE) cylinder heads. After two decades, the enlarged 6 litre V12 was offered in production in the XJS and Daimler Double Six, from 1991 and 1993 respectively. Including the V12 E-Type mark 3 models, and in the XJS (from 1975 to 1996), Jaguar made a total of 161,583 SOHC V12-engined cars.^[2] The Jaguar V12 was regarded as one of the premier power plants of the 1970s and 1980s.^[3] After launching the second generation XJ series in 1986, Jaguar developed their V12 into the racing engines that brought two overall victories at the 24 hours of Le Mans endurance races of 1988 and 1990.^[2]

Remarkably, three decades earlier, the engine was initiated in 1951 by Claude Baily as a prototype design for an intended Le Mans racecar: the Jaguar XJ13 - as well as for planned use in Jaguar’s range of luxury and sports cars. After building six DOHC engines, 3 of which were extensively tested in cars, the XJ13 project was terminated in 1967, before the car ever entered into competition. Under the direction of Jaguar Chief Engineer William Heynes, the DOHC V12 engine design was reworked by engineers Walter Hassan and Harry Mundy into a road-going SOHC production-vehicle version, first installed in the Jaguar E-Type mark 3 of 1971. The SOHC V12 was just the second production engine design in Jaguar's history, after the 1949 straight-six XK engine, built through 1992. It uses an all-aluminium block and cylinder heads with removable wet steel liners, and single overhead camshafts with two valves per cylinder.