Efficiency Boost Claimed by Mahle Variable Valve Timing System

TU-Editor

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7th August 2018

A new variable valve timing system claims to offer performance enhancing properties across management of exhaust gas temperature and save fuel or even an engine braking function.

The Mahle Shifting Roller System employs an adjustable cam follower brought into contact with one of the two cam lobes, which have different profiles. The electrically operated function claims a simple and robust design. 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 cycle engines. Mahle claims that, compared to having adjustable cam segments on the camshaft, the moving masses in its system are significantly smaller resulting in reduced internal forces and requiring less space.

When used as an engine brake, the system claims to work even at low speeds, thanks to its two-stroke mode and expects to perform at approximately the same level as the engine output. Because the cylinders can be activated individually, the engine brake can be actuated gradually and adapted to the current brake power requirements. At the same time, opening the exhaust valves sooner should allow the exhaust gas temperature to be increased improving fuel economy and emissions and it can allow for lower compression ratios transferring some of the compression work to the engine’s turbocharger.