Jaguar AJ6 engine
Encyclopedia
The AJ6 and the similar AJ16, was an inline-6 piston engine used by Jaguar
in the 1980s and 1990s. It was designed to replace the much-loved Jaguar XK6 engine
, and was introduced in 1984. The AJ6 was only the third engine ever designed by the company. The AJ16 was replaced in 1996 with the Jaguar developed Jaguar AJ-V8 engine
.
Jaguar had considered cutting the V12
in half to build a V6, or possibly a V8, but chose instead to develop a new inline-6. The cylinders are inclined, as in a slant-6, by 22 degrees. It uses an aluminum block to reduce weight, and has an optional DOHC head for higher efficiency and power.
. It had DOHC 4-valve heads with a 91 mm (3.6 in) bore and 92 mm (3.6 in) stroke. Power was 165 kW with 325 newton metre of torque. Power was reduced to 201 hp for versions having catalytic exhaust system. Early versions of the 3.6L AJ6 as used in the 1984 - 1987 XJ-S cars had a conventional distributor type of ignition system with electronics within the distributor body. This early AJ6 ignition system is nearly identical to the system used on the XK engine in the Series III XJ6 cars. The Lucas fuel injection system on the 3.6L AJ6 engines in these early XJ-S cars sensed engine load using a Manifold Absolute Pressure (MAP) sensor just like the V12 cars from the same era. Later 3.6L AJ6 engines as used in the 1986-1989 XJ40 cars had a crank sensor type of ignition system with a bare distributor that only carried the spinning ignition rotor inside the distributor cap. The fuel injection system used on the later 3.6L AJ6 engines used a hot wire Mass Air Flow sensor to determine engine load.
Vehicles using the 3.6 were:
, and was prone to failure. The block is the same as the 3.6, with the crankshaft and pistons lowering the stroke to 74.8 mm (2.9 in). Only the 1984-1989 Jaguar XJ6
used the 2.9. It was used for the entry-level XJ6 in Britain and Europe but rarely, if ever, seen in models exported to the US. The SOHC 2.9, which was generally considered somewhat underpowered for such a large car, was discontinued in 1990 (Actually 3.2 starts with a J-plate, so late 90 2.9 is possible) and replaced with a DOHC 3.2 (essentially identical to the DOHC 4.0).
The 2.9 Engine was, as in earlier years the 2.8 XK-engine, sized to match road-tax regulations in some European Countries like Italy or France. In France cars with more than 3 litres of engine size had to pay a luxury tax.
TWR modified XK40s resulting in the XJR. Jaguarsport was also formed as a partnership between TWR and Jaguar. The first XJR, the XJR 3.6L, had extensive appearance changes coupled with stiffer suspension, anti-roll bar/links, power steering valve that reduced efficiency by 40% and an LSD but no performance enhancements. Interior-wise it included special stitching, "sport" or "XJR" embossed front headrests, and Jaguarsport speedometer labels and tread-plates.
1990 XJRs had the upgraded 4L engine with the old style body-kits, and appearance changers.
XJR 4.0Ls from 1990 on Had all of the XJR 3.6 handling upgrades and benefits from engine enhancements such as high lift cams, improved double plenum inlet manifold, and a compression ratio of 9.75:1. They were sent directly after being produced to TWR in Coventry to be modified.
Exterior also changed again for last generation of the XJ40 XJR from H-registration year onwards. Bodykit was re-sculptured and the boot spoiler was deleted. Side mouldings were now added, with the smaller "XJR" badge embedded in them. Engine now had a plaque saying "Jaguarsport XJR 4L" on the rocker cover. XJR badge size was decreased on the boot (had previously ranged from XJR-3.6, XJR-4L, 4-litre and "XJR". The later one ("XJR") is most common and the only badge you could choose on the boot infil panel models. A "sport" one on the front within its own unique XJR grill. In this unique grill a "sport" badge was installed. Interior even had XJR specific wood (SPB part number).
Total XJ40 cars built was 208,733 and supposedly 500 JaguarSport cars built, 200 of the round headlight versions and then about 300 with the square headlights like the Sovereigns and Daimler's. 1990+ XJR power output is around 250 bhp / 278 lbft.
Following the launch of the Aston Martin DB7
, a car based on Jaguar's original replacement platform for the XJS (which was discarded in favour of the XK8 based on the X300 platform, note the traditional Jaguar 6-dial dashboard and ski-slope), the Jaguar AJ6 was used by Aston Martin as well. This version featured an Eaton
supercharger
.
Cars using the 4.0 and 3.2 included:
(XK8 and XJ8 in 1996/7).
Cars using the 4.0 and 3.2 included:
which used an Eaton
M90 blower to boost output to 240 kW and 512 newton metre.
Jaguar (car)
Jaguar Cars Ltd, known simply as Jaguar , is a British luxury car manufacturer, headquartered in Whitley, Coventry, England. It is part of the Jaguar Land Rover business, a subsidiary of the Indian company Tata Motors....
in the 1980s and 1990s. It was designed to replace the much-loved Jaguar XK6 engine
Jaguar XK6 engine
The renowned Jaguar XK dual overhead camshaft inline 6-cylinder engine was introduced in 1949 and continued in manufacture until 1992. It was produced in five displacements for Jaguar passenger cars, with other sizes being made by Jaguar and privateers for racing...
, and was introduced in 1984. The AJ6 was only the third engine ever designed by the company. The AJ16 was replaced in 1996 with the Jaguar developed Jaguar AJ-V8 engine
Jaguar AJ-V8 engine
The Jaguar AJ-V8 is a compact DOHC V8 piston engine used in many Jaguar vehicles. It was the fourth new engine type in the history of the company. In 1997 it replaced both designs previously available on Jaguar cars: the straight-6 Jaguar AJ6 engine , and the Jaguar V12 engine...
.
Jaguar had considered cutting the V12
Jaguar V12 engine
Jaguar V12 piston engine was one of the premier powerplants of the 1970s and 1980s. It was first seen in the Series 3 Jaguar E-type of 1971 and 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...
in half to build a V6, or possibly a V8, but chose instead to develop a new inline-6. The cylinders are inclined, as in a slant-6, by 22 degrees. It uses an aluminum block to reduce weight, and has an optional DOHC head for higher efficiency and power.
AJ6
The original engines were the DOHC 3.6 and the SOHC 2.9. The DOHC 3.6 was revised and enlarged to 4.0 in 1990. It is still essentially an "AJ6", however. This was, as per usual, offered for the XJ-S before it was built into the XJ40 saloon.3.6
The 3.6 was the first AJ6 engine, debuting in 1983 on the XJ-SJaguar XJS
The Jaguar XJ-S is a luxury grand tourer produced by the British manufacturer Jaguar from 1975 to 1996. The XJ-S replaced the E-Type in September 1975, and was based on the XJ saloon. It had been developed as the XK-F, though it was very different in character from its predecessor...
. It had DOHC 4-valve heads with a 91 mm (3.6 in) bore and 92 mm (3.6 in) stroke. Power was 165 kW with 325 newton metre of torque. Power was reduced to 201 hp for versions having catalytic exhaust system. Early versions of the 3.6L AJ6 as used in the 1984 - 1987 XJ-S cars had a conventional distributor type of ignition system with electronics within the distributor body. This early AJ6 ignition system is nearly identical to the system used on the XK engine in the Series III XJ6 cars. The Lucas fuel injection system on the 3.6L AJ6 engines in these early XJ-S cars sensed engine load using a Manifold Absolute Pressure (MAP) sensor just like the V12 cars from the same era. Later 3.6L AJ6 engines as used in the 1986-1989 XJ40 cars had a crank sensor type of ignition system with a bare distributor that only carried the spinning ignition rotor inside the distributor cap. The fuel injection system used on the later 3.6L AJ6 engines used a hot wire Mass Air Flow sensor to determine engine load.
Vehicles using the 3.6 were:
- 1984-1989 Jaguar XJ-SJaguar XJSThe Jaguar XJ-S is a luxury grand tourer produced by the British manufacturer Jaguar from 1975 to 1996. The XJ-S replaced the E-Type in September 1975, and was based on the XJ saloon. It had been developed as the XK-F, though it was very different in character from its predecessor...
- 1986-1989 Jaguar XJ6Jaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- 1986-1989 Jaguar XJ6 SovereignJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- 1986-1989 DaimlerJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
2.9
The 2.9 used a SOHC head from the Jaguar V12 engineJaguar V12 engine
Jaguar V12 piston engine was one of the premier powerplants of the 1970s and 1980s. It was first seen in the Series 3 Jaguar E-type of 1971 and 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...
, and was prone to failure. The block is the same as the 3.6, with the crankshaft and pistons lowering the stroke to 74.8 mm (2.9 in). Only the 1984-1989 Jaguar XJ6
Jaguar XJ
Jaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
used the 2.9. It was used for the entry-level XJ6 in Britain and Europe but rarely, if ever, seen in models exported to the US. The SOHC 2.9, which was generally considered somewhat underpowered for such a large car, was discontinued in 1990 (Actually 3.2 starts with a J-plate, so late 90 2.9 is possible) and replaced with a DOHC 3.2 (essentially identical to the DOHC 4.0).
The 2.9 Engine was, as in earlier years the 2.8 XK-engine, sized to match road-tax regulations in some European Countries like Italy or France. In France cars with more than 3 litres of engine size had to pay a luxury tax.
4.0 (1989-1994)
The 24 valve DOHC 4.0 L (3980 cc) version replaced the 3.6 L AJ6 in 1989. It featured a longer 102 mm (4 in) stroke, and generated 183 kW power and 392 newton metre of torque. The 4.0L engines as used in the 1990-1994 XJ40 cars continued with the crank sensor and empty distributor type of ignition system and the hot wire Mass Air Flow sensor type of fuel injection control system as the 1988-1989 3.6L XJ40 cars.TWR modified XK40s resulting in the XJR. Jaguarsport was also formed as a partnership between TWR and Jaguar. The first XJR, the XJR 3.6L, had extensive appearance changes coupled with stiffer suspension, anti-roll bar/links, power steering valve that reduced efficiency by 40% and an LSD but no performance enhancements. Interior-wise it included special stitching, "sport" or "XJR" embossed front headrests, and Jaguarsport speedometer labels and tread-plates.
1990 XJRs had the upgraded 4L engine with the old style body-kits, and appearance changers.
XJR 4.0Ls from 1990 on Had all of the XJR 3.6 handling upgrades and benefits from engine enhancements such as high lift cams, improved double plenum inlet manifold, and a compression ratio of 9.75:1. They were sent directly after being produced to TWR in Coventry to be modified.
Exterior also changed again for last generation of the XJ40 XJR from H-registration year onwards. Bodykit was re-sculptured and the boot spoiler was deleted. Side mouldings were now added, with the smaller "XJR" badge embedded in them. Engine now had a plaque saying "Jaguarsport XJR 4L" on the rocker cover. XJR badge size was decreased on the boot (had previously ranged from XJR-3.6, XJR-4L, 4-litre and "XJR". The later one ("XJR") is most common and the only badge you could choose on the boot infil panel models. A "sport" one on the front within its own unique XJR grill. In this unique grill a "sport" badge was installed. Interior even had XJR specific wood (SPB part number).
Total XJ40 cars built was 208,733 and supposedly 500 JaguarSport cars built, 200 of the round headlight versions and then about 300 with the square headlights like the Sovereigns and Daimler's. 1990+ XJR power output is around 250 bhp / 278 lbft.
3.2 (1990-1994)
A 24 valve DOHC 3.2 L, essentially a shorter-stroke (83 mm) 4.0 L, replaced the 12 valve SOHC 2.9 in 1990. It produced 149 kW of power and 298 newton metre of torque, and proved a popular engine in Europe (sales outnumbered 4.0 L saloons roughly 4:1) but was not exported to America.Following the launch of the Aston Martin DB7
Aston Martin DB7
The Aston Martin DB7 is a grand tourer which was produced by Aston Martin from September 1994 to December 2004. The grand tourer was available either as a coupé or a convertible. The prototype was complete by November 1992, and debuted at the Geneva Motor Show in March, 1993, the car was styled by...
, a car based on Jaguar's original replacement platform for the XJS (which was discarded in favour of the XK8 based on the X300 platform, note the traditional Jaguar 6-dial dashboard and ski-slope), the Jaguar AJ6 was used by Aston Martin as well. This version featured an Eaton
Eaton Corporation
Eaton Corporation is a global diversified power management company with 2010 sales of $13.7 billion. The company is a leading provider of electrical components and systems for power quality, distribution and control; hydraulics components, systems and services for industrial and mobile equipment;...
supercharger
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
.
Cars using the 4.0 and 3.2 included:
- Jaguar XJSJaguar XJSThe Jaguar XJ-S is a luxury grand tourer produced by the British manufacturer Jaguar from 1975 to 1996. The XJ-S replaced the E-Type in September 1975, and was based on the XJ saloon. It had been developed as the XK-F, though it was very different in character from its predecessor...
(4.0 only) - Aston Martin DB7Aston Martin DB7The Aston Martin DB7 is a grand tourer which was produced by Aston Martin from September 1994 to December 2004. The grand tourer was available either as a coupé or a convertible. The prototype was complete by November 1992, and debuted at the Geneva Motor Show in March, 1993, the car was styled by...
(modified, supercharged 3.2) - Jaguar XJ6Jaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- Jaguar SovereignJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- Jaguar XJRJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
(4.0 only) - Daimler SixJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
AJ16
Both the 3.2 and 4.0 were substantially revised for the 1995 launch of the new X300 saloon. These are the "AJ16" engines, both now featuring coil-on-plug distributorless ignition, new engine management systems, magnesium alloy valve covers, revised pistons and other detail changes. The AJ16 was discontinued with the launch of the AJ-V8Jaguar AJ-V8 engine
The Jaguar AJ-V8 is a compact DOHC V8 piston engine used in many Jaguar vehicles. It was the fourth new engine type in the history of the company. In 1997 it replaced both designs previously available on Jaguar cars: the straight-6 Jaguar AJ6 engine , and the Jaguar V12 engine...
(XK8 and XJ8 in 1996/7).
4.0 / 3.2 (1994-1997)
For the launch of the new X300 saloon for 1995, substantial revisions were made to the 4.0 L and 3.2 L AJ6 engines. The new design was called the AJ16 to reflect the major differences between it and the original AJ6.Cars using the 4.0 and 3.2 included:
- Jaguar XJSJaguar XJSThe Jaguar XJ-S is a luxury grand tourer produced by the British manufacturer Jaguar from 1975 to 1996. The XJ-S replaced the E-Type in September 1975, and was based on the XJ saloon. It had been developed as the XK-F, though it was very different in character from its predecessor...
(4.0 only) - Jaguar XJ6Jaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- Jaguar XJ6 SovereignJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- Jaguar XJ6 SportJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
- DaimlerJaguar XJJaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
AJ16S
A supercharged version of the 4.0 L AJ16 was released in 1994 in the Jaguar XJRJaguar XJ
Jaguar XJ is the designation that has been used for a series of luxury saloon cars sold under the British Jaguar marque. The first XJ was launched in 1968 and the designation has been used for successive Jaguar flagship models since then. The original model was the last Jaguar saloon to have had...
which used an Eaton
Eaton Corporation
Eaton Corporation is a global diversified power management company with 2010 sales of $13.7 billion. The company is a leading provider of electrical components and systems for power quality, distribution and control; hydraulics components, systems and services for industrial and mobile equipment;...
M90 blower to boost output to 240 kW and 512 newton metre.
See also
- Jaguar XK6 engineJaguar XK6 engineThe renowned Jaguar XK dual overhead camshaft inline 6-cylinder engine was introduced in 1949 and continued in manufacture until 1992. It was produced in five displacements for Jaguar passenger cars, with other sizes being made by Jaguar and privateers for racing...
- Jaguar V12 engineJaguar V12 engineJaguar V12 piston engine was one of the premier powerplants of the 1970s and 1980s. It was first seen in the Series 3 Jaguar E-type of 1971 and 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...
- Jaguar AJ-V6 engineJaguar AJ-V6 engineThe Jaguar AJ-V6 engine is a specialized version of Ford's Duratec 25/30 V6. One notable addition is the use of variable valve timing, a feature also shared with Mazda's version of the engine. It is available in 2.0 L, 2.5 L and 3.0 L displacements.Jaguar's AJ-V6 engine has an...
- AJ6 Performance