The intention with this build, is to have 4wd and a modern V6. This presents numerous obstacles to overcome.
The Jaguar X-type shares a common bond with the Mondeo ST220. The Duratec V6 is an excellent engine and can be mounted to the Getrag 221 gearbox (from the S-type Jag) for rear wheel drive applications. However, 4wd is the goal.
The Duratec is mounted sideways within the X-type and uses a version of the MTX75 gearbox; with attached transaxle/differential; to drive the front wheels. Once the engine is turned around in the chassis and mounted to the Sierra’s MT75 4×4 gearbox via an adapter plate, a seperate front differential will be needed; such as one from the Ford Sierra XR4x4.
While Ford has reaped the Duratec’s benefit, it was not an original design. The Duratec V6 was originally developed by Mazda / Suzuki under the name KLZE. The primary input for the Ford version of this engine was Porsche, which was already developing the configuration for other purposes. Porsche sold the engineering to Ford and Cosworth, the dominant force behind the cylinder head design.
It’s used by many manufacturers including Jaguars, Lincoln, Land Rover, Ford, Volvo etc.
It is available in many guises from 2.0 to 3.7 litres.
The reason for choosing this engine is it seemed to tick all the right boxes. I was looking for a unit that was, powerful, light and compact, but also, reliable and economical to run.
In the UK the 2.5 and 3.0 versions are available in the Mondeo and Jaguar S and X types.
The Duratec 25 is a 2.5 L (2544 cc) 60° V6 and was introduced in 1994. It was developed for the Ford Mondeo and used in the Ford Contour, Jaguar X Type, and others. Bore is 82.4 mm and stroke is 79.5 mm.
The 3.0 L ‘Duratec 30’ or Mazda ‘AJ’ was introduced in 1996. It has 2967 cc of displacement and produces between 200 and 240 hp (150 and 180 kW). The same basic engine is used in the Jaguar S Type, Lincoln LS, Mazda MPV, Mazda6, Mondeo ST220 and many other Ford vehicles. It is essentially a bored-out (to 89 mm) Duratec 25. Versions include the Duratec ST (226hp) and Duratec Titanium (204hp) from the Mondeo ST220 and Titanium.
Jaguar AJ V6 engine/AJ-30
The 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 aluminium engine block and aluminium DOHC cylinder heads. It uses SFI fuel injection, has 4 valves per cylinder with VVT and features fracture-split forged powder metal connecting rods and a one-piece cast camshaft, another differentiator from the Ford and Mazda versions.
AJ30 – my choice
The AJ30 is a 3.0 L (2967 cc) version and is the most common. It has an 89 mm bore and shares the 2.5’s 79.5 mm stroke. In the S Type, it produces 240 hp and 216 ft-lb.
Amongst others this engine is used in:-
- 2000–present Jaguar S-Type, 240 hp (179 kW) and 216 ft-lb (293 N·m)
- 2002–present Jaguar X-Type, 231 hp (172 kW) and 209 ft-lb (283 N·m)
- 2009–present Jaguar XF, 240 hp (179 kW) and 221 ft-lb (300 N·m)
The Jaguar XF will debut a refined version of the AJ30 with continuously variable cam-phasing and variable geometry air intakes to increase power and broaden the power band up to its 6800 rpm redline.
The more traditional layout of the S Type Jaguar being, front engine/rear wheel drive, means this engine is longitudinally mounted, as opposed to transverse mounted as in the X-Type. Therefore, this means the exhaust manifolds are usable as they are both facing towards the rear, the engine mounts are roughly in the right place and the cooling system is all fed from the front by a separate and easily removable water pump. Also, maybe this variant could be the better choice due to Jaguar’s engineering input in it’s final design, and with the inclusion of variable valve timing amongst other things.
3D CAD model
Because modelling the Duratec with 100% accuracy was going to take months, a crude block format model was generated.