Jaguar X-Type 2.0, 2.5 and 3.0L

The Jaguar AJ-V6 engine is a specialized version of Ford's Duratec 25/30 V6 with the notable addition of variable valve timing, a feature only shared with Mazda's version of the engine. It is available in 2.0 L, 2.5 L and 3.0 L displacements.

As well as variable valve timing the Jaguar's AJ-V6 engine has an aluminium engine block and aluminium DOHC cylinder heads. Each cylinder is equipped with 4 large valves per cylinder (two inlet, two outlet), a one-piece cast camshaft has direct-acting mechanical bucket (DAMB) tappets, and fracture-split forged powder metal connecting rods. It uses SFI fuel injection differentiating the AJ-V6 compleatly from the Ford and Mazda versions of the engine.

The AJ-V6 2.0LThe AJ20 2.1 L displaces 2099cc, although it is marketed as a 2.0L it has an 81.6 mm (3.2 in) bore and 66.8 mm (2.6 in) stroke. It produces 157 hp. The compression ratio is 10.75:1., 2.5LThe AJ25 2.5 L displaces 2495 cc. It has an 81.6 mm (3.21 in) bore and 79.5 mm (3.1 in) stroke. It can deliver up to 192 hp (201 hp) @ 6800rpm. The compresion ratio is 10.3:1. Jaguar X-Type 2.5, 194 hp (145 kW; 197 PS) and 180 lbft (240 Nm) Jaguar S-Type 2.5 (UK), 201 hp (150 kW; 204 PS) and 185 lbft (251 Nm) ,and 3.0LThe AJ30 3.0 L displaces 2967 cc It has an 89 mm (3.5 in) bore and 79.5 mm (3.1 in) stroke. In the X-Type, it produces up to 240 hp Jaguar S-Type, 240 hp (179 kW; 243 PS) and 216 lbft (293 Nm) Jaguar X-Type, 231 hp (172 kW; 234 PS) and 209 lbft (283 Nm) Jaguar XF, 240 hp (179 kW; 243 PS) and 221 lbft (300 Nm) , engines are a true hybrid of design,the six cylinder 60 degree V engine started life with Mazda and Suzuki, Porsche continued to develop the engine before they sold it on to Cosworth and Ford. Ford was already well entrenched with Mazda who also contributed substantially to further development.

The engine named Duratec is based on two main types the 2.5 and 3.0L, there are a number variations on this the most notable is a 6L V12 configuration custom built by Cosworth for Aston Martin


The Duratec is liquid cooled it has an aluminium cylinder block, the engine is fitted with aluminium pistons that have cut-outs on the top to allow the piston to clear the valve heads for any available combination of the camshaft profile. This is mainly required because of the variable valve phasing as a result of the Variable Camshaft Timing (VCT).

The Jaguar uses two aluminium cylinder heads with twin overhead camshaft's (one inlet one outlet)in each, four valves are used per cylinder with the VCT acting upon the inlet camshaft. Each head is fitted with two individually hydraulically tensioned timing chains.

The VCT intake system is electronically controlled by the engine management system and varies the inlet valve operation between fully open and fully closed at various calibrated engine speeds, this improves effecency, engine torque and overall engine performance.

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