Variable valve timing that is adapted to the different engine operating conditions can be achieved with its Shifting Roller system, claims Mahle. It features an adjustable cam follower, that can be brought into contact with one of the two cam lobes, which have different profiles, says the company. Depending on the lift curve of the second cam lobe, the engine can be operated as a permanent brake, for exhaust gas temperature management, or for use with Miller cycles.
It’s claimed that moving masses in the Shifting Roller system are smaller compared with adjustable cam segments on the camshaft, and that this results in lower actuating forces and reduced installation space. Mahle says the electrically actuated systems are temperature independent, allow selective cylinder activation, and switch between the operating states quickly.