Intake Valve Lift Control System
The intake valve lift control is an electro-hydraulically operated system used to create a dual high/low lift system for the intake valves. This dual lift system reduces engine parasitic pumping losses by using intake valve lift to better match the amount of air entering the cylinders to the engine's specific real-time load requirements. The control system switches between low and high valve lift, depending on needed engine output and is fully integrated with the camshaft actuator system to provide both timing and lift control of the intake valves.
The engine operates in low-lift mode when full power is not required. The duration of the intake valve opening in low-lift mode is reduced from that used in an engine with only a single-lift valve. This limits airflow into the engine without the normal parasitic pumping losses that occur when the inlet flow is throttled, resulting in enhanced vehicle fuel economy.
The engine operates in high-lift mode when full power is required. The duration and lift of the intake valve are both increased to allow high airflow into the engine, resulting in high engine power and strong vehicle acceleration.