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Jaguar V12
Manufacturer	Jaguar Cars
Production	1971–1996
Successor	Jaguar AJ-V8
Class	SOHC V12
Engine	5.3 L (5343 cc/326 in³) 6.0 L (5994 cc/365 in³)

Jaguar's V12 was one of the premiere powerplants of the 1970s and 1980s. It was a V12 piston engine, The engine first seen in the Series 3 E-type of 1971 was based loosely on an earlier design intended for a Le Mans car, the ill-fated Jaguar XJ13. The V12 was only Jaguar's second engine design to go into production in the history of the company. The all alloy block was fitted with removable wet liners and had a SOHC 2-valve alloy head with flat combustion chambers.

Contents 1 5.3 1.1 5.3 HE 2 6.0 HE 3 TWR/Lister 4 See also

The original 5.3 L (5343 cc) version had an oversquare 90 mm bore and 70 mm stroke. It produced 210 kW (285 hp) (245 to 299 bhp depending on emission controls and compression ratio) and 400Nm (295 Lb-Ft) in fuel-injected form. Right from the start of production in 1971 for the Series 3 E-Type, the V12 engine had Lucas OPUS electronic ignition. This system was used until 1982 when the Lucas CEI system was introduced. When first issued, the OPUS ignition amp unit was secured directly to the engine between the cylinder heads and had problems due to overheating. Later cars had the ignition amplifier moved away from the engine where it could get air flow for cooling. Originally the V12 was supposed to get an advanced Fuel Injection system under development by AE Brico. When that was cancelled at a late stage, possibly due to concerns that the design was too similar to Bosch products, the V12 as used in the Series 3 E-Types and the S1 XJ12 cars had four Zenith-Stromberg side draft carburetors. In the middle of 1975, the V12 engine used in the S2 XJ12 and the new XJ-S had a Lucas fuel injection system which was based around the Bosch D-Jetronic system.

This version was used in the following cars:

• Jaguar E-Type
• 1975-1981 Jaguar XJS
• 1972-1981 Jaguar XJ12 (Series 1 and 2)
• 1973-1981 Daimler Double Six (Series 1 and 2)
• Panther J72
• Panther De Ville

A High-Efficiency 5.3 HE debuted in 1981. This version of the engine used the special high swirl design 'May' cylinder head, and had an unusually high compression ratio (10.5:1 - 12.5:1 depending on market and year). In any given market, power levels remained similar to the previous model, but fuel economy was up by nearly 50%. The HE V12 engines had a fuel injection or engine control system from Lucas that was based on the Bosch P-Jetronic system. The Lucas CEI ignition system continued until mid 1989 when it was superseded by a system from Magneti Marelli on the XJ-S. Series 3 XJ12 and Daimler Double Six cars used the Lucas CEI system until the end of production in 1992. The Marelli ignition system was used until the end of XJ-S production and on the 6.0L V12 used in the XJ81 four door saloons made in 1993-1994. The 6.0 litre X305 1995-96 XJ12 and Daimler Double-Six cars had a new Nippondenso distributor-less crank fired ignition system with coil packs that are very similar to Ford EDIS-6 units.

The 5.3 HE was used in these cars:

• 1981-1992 Jaguar XJ12 (Series 3)
• 1981-1992 Jaguar XJS
• 1981-1992 Daimler Double Six (Series 3)

The engine was stroked to 78.5 mm in 1992 for a displacement of 6.0 L (5994 cc) to make this the most powerful Jaguar production engine to date.

The 6.0 HE was used in the following cars:

• 1992-1995 Jaguar XJS
• 1993-1995 Jaguar XJ12 (XJ81)
• 1995-1996 Jaguar XJ12 (X305)
• 1993-96 Daimler Double Six (XJ81 and X305)

In 1985, Tom Walkinshaw Racing became Jaguar's official team in World Endurance Championship, taking over the project from American team Group 44. Their first car, XJR6, used the 6.0 L engine, but in the following year the engine was upgraded to 6.9 L and in 1988 the XJR9 used the engine's most famous displacement of 7.0 L. By 1991, the V12 was good for 7.4 L inside the XJR12, developing an impressive 750 bhp.

TWR also upgraded production Jaguar cars (usually XJ-S), with a variety of styling, handling and performance modifications. Most of the cars thus modified were straight from the Jaguar factory and sold through Jaguar dealerships. By 1989, TWR were selling moderate numbers of XJ-S fitted with a 6.0 litre version of the V12, which pre-dated the Jaguar production version by some 3 years.

Lister Cars, a well-known Jaguar tuner with a long history of technical collaboration with the British automaker, was the first to use the TWR-tuned engine in a road car. In 1991, they fitted the 7.0 L (6996 cc/427 in³) version of the engine, with a 94 mm (3.7 in) bore and 84 mm (3.3 in) stroke, into a modified Jaguar XJS, which was rebadged Lister Le Mans. This engine officially produced 407.2 kW (546 hp) and 786.37 N·m (580 ft·lbf). From 1993, Lister owner Laurence Pearce produced the company's first design the Lister Storm, which, naturally, continued using the V12 engine, both on the road and on the track, with the car becoming a mainstay of the FIA GT Championship and several national championships for the following decade.

• Jaguar XK6 engine
• Jaguar AJ6 engine
• V12 Performance

Jaguar Cars, a subsidiary of Ford since 1989, road and race car timeline, 1940s-1980s  v • d • e
Type	1940s					1950s										1960s										1970s										1980s
	5	6	7	8	9	0	1	2	3	4	5	6	7	8	9	0	1	2	3	4	5	6	7	8	9	0	1	2	3	4	5	6	7	8	9	0	1	2	3	4	5	6	7	8	9
Sports				XK120							XK140			XK150			E-type S1							E S2			E-type S3				XJ-S						XJ-S HE
Saloon											Mark 1					Mark 2, 240, 340
																				S-Type											XJ-C
																						420		XJ6 Ser I						XJ6 Ser II						XJ6 Ser III								XJ6 (XJ40)
	Mk IV				Mk V			Mk VII				Mk VIII			Mk IX			Mk X				420G						XJ12		XJ12 S II						XJ12 Ser III
Supercar														XKSS
Racing							C-Type			D-Type								E-Type				XJ13										XJ-C		Jaguar XJ41& XJ42						XJRs
Corporate ownership	Independent																					BMH		British Leyland															Independent					Ford