Jaguar’s Highly Acclaimed 2.7 Litre V6 Diesel - With Active Engine Mounts
The combination of a modern turbodiesel engine and the highly advanced aluminium body of the XJ range delivers an exceptional package of performance, dynamics, refinement and economy. All the advantages of modern diesel engines - fuel efficiency, relaxed motoring and impressive power delivery - are only amplified by linking them to a super-strong and lightweight chassis, like that of the XJ.
Launched in Jaguar’s mid-range S-TYPE saloon in 2004, Jaguar’s state-of-the-art twin-turbo V6 Diesel sets new standards in refinement and performance. The highly efficient 24-valve engine features advanced technologies, including the latest generation high-pressure, commonrail, direct-injection fuel system and a lightweight, compacted graphite iron (CGI) cylinder block.
The outstanding strength and durability of CGI means that less material is needed than for a conventional cast iron block, ensuring reduced engine weight and length. In fact, the new diesel engine is the lightest unit of its type, at just 202kg. This significantly contributes to the excellent power-to-weight ratio and fuel economy.
Other features at the heart of the engine provide the capability to deliver high performance and excellent durability. Cast aluminium pistons incorporate ‘double wave-gallery’ cooling. In this process, oil is sprayed precisely onto the inside of the pistons from jets in the block. The oil then flows through two internal wave-shaped channels to help cool each piston crown. This arrangement also has the indirect benefit of reducing piston ‘slap’ noise.
Management of the engine’s noise characteristics has focused particularly on injector tick and combustion noise, which is controlled through the use of next-generation commonrail technology, including ‘multiple-point’ injection and closed-loop injection control, which ensure that the combustion is smooth under all operating conditions.
The fuel quantity provided by each injector is controlled by a Piezo actuator, which enables highly accurate fuel metering of up to five injections per cycle. These features provide an extremely fine spray of diesel fuel, which ensures the most uniform fuel-air mixture possible, resulting in a more complete combustion process. As a result, the diesel engine is able to achieve both high power and the desired emissions capability.
From the outset, the 2.7 twin-turbo Diesel engine was designed to meet future emissions levels. However, further advances in reducing emissions since the launch of the S-TYPE twin-turbo Diesel have been made through changes to the fuel injection system, utilising higher injection pressures and different injector spray patterns. The calibration of the electronically actuated turbochargers, the exhaust gas recirculation system and port deactivation have also been revised. With the addition of a Catalysed Diesel Particulate Filter (CDPF), the advanced design of the V6 engine ensures it exceeds Euro Stage IV emissions requirements.
Aiding both performance and emissions is a forced induction system, comprising twin-turbochargers with state-of-the-art electronic actuation. Traditionally, turbochargers are vacuum actuated, but this new form of rotary electric actuator gives a higher degree of control, providing benefits in the areas of emissions and transient engine performance, as well as in balancing performance and emissions between the two cylinder banks. The turbochargers are a low inertia type for quick, responsive, power delivery.