System Functions: Valvetronic

The Valvetronic consists of fully variable control of the valve lift combined with the variable camshaft control unit (VANOS).

The valve lift is only regulated on the inlet side, but the camshaft is also adjusted on the exhaust side. Valvetronic is controlled by:

• a variable valve lift of the inlet valve
• a variable opening duration of the inlet valve
• a variable camshaft control of the inlet and exhaust camshaft

(double VANOS)

The system is optimized by adapting the valve gear, changing the actuator motor and varying the camshaft timing control. Major innovations are:

• On the intermediate lever, the plain bearing to the eccentric shaft has been replaced by a roller bearing. This reduces the friction in the valve gear.
• The guide of the intermediate lever is more precise. Only one spring is required to guide and retain the intermediate lever.
• The moved mass of the valve gear has been reduced by 13%.
• The range of motion of the inlet valves has been improved. The maximum lift has risen to 9.9 mm, but above all the minimum lift has been further reduced to 0.18 mm.