Variable Valve Timing Actuator: Description and Operation

The Variable Cam Shaft Timing (VCT) unit is connected to the exhaust camshaft, and the rotation of the exhaust camshaft takes place in the VCT unit. The unit is oil-filled to move the pistons inside the VCT unit. The oil and piston movement inside the unit can retard the exhaust camshaft without affecting the intake camshaft.

The VCT unit variable adjustment allows every piston position between maximum advance and maximum retardation.