Variable Valve Timing Solenoid: Description and Operation

VTEC - Valve Train:

VTEC - System Description:

DESCRIPTION
The Variable Valve Timing Solenoid opens and closes a oil passage leading to the rocker arm assembly, allowing engine oil to pressurize the locking pins in the intake rocker arms.

OPERATION
When the proper conditions have been met, the Engine Control Module (ECM) signals the solenoid valve to open by applying battery voltage. The open valve allows engine oil at operating pressure to enter the rocker arm assembly and move pins located in the primary, secondary and middle rocker arms, locking them together. The middle rocker follows a high lift and duration lobe. Once locked together, both intake valves open and close in response to this high performance cam lobe profile.

CONSTRUCTION
An electromagnetically activated spool valve in a cast aluminum housing.