The Jaguar AJ-V6 engine is a piston engine based on the Ford Duratec V6 engine. The Duratec V6 was originally a Porsche design, purchased by the Ford Motor Company with Cosworth finishing the engineering to suit Ford's needs. 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 2.1 L (2,099 cc), 2.5 L (2,495 cc) and 3.0 L (2,967 cc) displacements. The AJ-V6 engine has an aluminium engine block and Jaguar Cars designed aluminium DOHC cylinder heads. It uses sequential fuel injection, has 4 valves per cylinder with VVT, features fracture-split forged powder metal connecting rods and a one-piece cast camshaft and has direct-acting mechanical bucket (DAMB) tappets, these design aspects differentiating the AJ-V6 from the Ford and Mazda versions.