Rover KV6 Engine - Technology

Technology

At introduction, the engine enjoyed considerable technological advancement compared with its competition, most notably being the lightest and shortest v6 in its class. It has fully automatically tensioned drive belts and adaptive Siemens EMS2000 engine management. The fuelling and ignition timing are constantly varied to match the load on the engine to improve refinement. The engine boasts Variable Geometry Induction, whereby air induction pipe lengths vary to optimise engine torque in response to different engine and road speeds, aiding refinement and efficiency. Although it bears the name of K Series, the engine has almost no components in common with the 4-cylinder version.

In its Rover setup, the unit delivers peak engine power of 175 PS (129 kW) at 6,500 rpm, and maximum torque of 240 N·m (177 lb·ft) at 4000 rpm, prompting the late 1990s 'most powerful in its class' sales tag used to sell Rover 800 V6 models. The automatic gearbox in V6 800s is also able to communicate with the engine, briefly easing torque to allow smoother changes.

One of the most immediately noticeable features of the first V form engine to be designed by Rover for decades is its distinctive, quietly growling engine note.

Cam Drive

The V6 engine is fitted with four overhead camshafts driven by synchronous tooth belts. It has a single, long, serpentine belt at the front driving the inlet cams and also the coolant pump. The exhaust cams are driven by short link belts driven from the ends of the inlet cams at the rear of the engine. The system was a joint development between Dayco (belt supplier) and Rover. The rear link belts do not incorporate any tensioning device. Belt tension is maintained by very careful control of belt length and the pulley pair is pre-tensioned during fitting. The front belt drive is tensioned by a spring-loaded tensioner pulley incorporating a hydraulic damping element.

An unusual feature of this system is that it incorporates "floating" inlet cam drive pulleys that are not directly keyed to the shafts. This means that special setting tools are required to establish the cam timing before the pulley fixings are tightened. This requirement is the result of the complexity of the cam drive train. In addition to the length and thickness tolerance of the belts, the accuracy of the cam timing is also affected by the positional and diameter tolerance of each pulley and the thickness of each major engine casting. The result is that the required degree of timing accuracy could not otherwise be maintained.