Continuous Variable Valve Timing: Operation

• The CVVT system makes continuous intake valve timing changes based on operating conditions.
• Intake valve timing is optimized to allow the engine to produce maximum power.
• Cam angle is advanced to obtain the EGR effect and reduce pumping loss. The intake valve is closed quickly to reduce the entry of the air/fuel mixture into the intake port and improve the changing effect.
• Reduces the cam advance at idle, stabilizes combustion, and reduces engine speed.
• If a malfunction occurs, the CVVT system control is disabled and the valve timing is fixed at the fully retarded position.
  Fig 1: Identifying Cam Angle

  Courtesy of HYUNDAI MOTOR CO.
  Fig 2: Advance Operation Pattern

  Courtesy of HYUNDAI MOTOR CO.
  Fig 3: Identifying Rotor Vane And Housing Vane

  Courtesy of HYUNDAI MOTOR CO.

1. Fig 3 shows the relative operation structures of the housing vane to the rotor vane.
2. If the CVVT is held a certain control angle, to hold this state, oil is replenished as much as oil leaks from the oil pump.

   The OCV (Oil-flow Control Valve) spool location at this time is as follows.

Oil pump --> Advance oil chamber (Little by little open the inflow side to the advance oil chamber) --> Almost close the drain side 

Be sure there might be a difference in the position according to the engine running state (rpm, oil temperature, and oil pressure).