VANOS

VANOS is a variable valve timing system used by BMW on various automotive petrol engines since 1992.

VANOS is a variator system that varies the timing of the valves by moving the position and the camshafts in relation to the drive gear.

At lower engine speeds, the position of the camshaft is moved so the valves are opened later, as this improves idling quality and smooth power development.

As the engine speed increases, the valves are opened earlier: this enhances torque, reduces fuel consumption and lowers emissions.

At high engine speeds, the valves are opened later again, because this allows full power delivery.