Operation Principle

WARNING: This page is about a different variant/trim than selected.

The CVVT has the mechanism rotating the rotor vane with hydraulic force generated by the engine oil supplied to the advance or retard chamber in accordance with the CVVT oil control valve control.

Information

A separate solenoid valve is installed on the chain cover in the intake side for closing and releasing a separate lock pin.

Courtesy of KIA MOTORS AMERICA, INC.

[CVVT System Mode]

Courtesy of KIA MOTORS AMERICA, INC.

Courtesy of KIA MOTORS AMERICA, INC.

Driving Condition	Exhaust Valve		Intake Valve
Driving Condition	Valve Timing	Effect	Valve Timing	Effect
(1) Low Speed/Low Load	Completely Advance	* Valve Under-lap * Improvement of combustion stability	Completely Retard	* Valve Under-lap * Improvement of combustion stability
(2) Part Load	Retard	* Reduction of HC	Retard	* Delays the closing time of intake valve to reduce pumping loss * Increases expansion work
(3) Low Speed/High Load	Retard	* Increase of expansion work	Advance	* Prevention of intake back flow (Improvement of volumetric efficiency)
(4) High Speed/High Load	Advance	* Reduction of pumping loss	Retard	* Improvement of volumetric efficiency