Mazda CX-5 Service & Repair Manual: Variable Valve Timing Mechanism

Outline

• Achieves optimum valve timing according to the driving conditions by the variable valve timing mechanism changing the phases of the camshaft.

• An electric type variable valve timing mechanism on the intake side and a hydraulic pressure type on the exhaust side has been adopted. The expansion of the valve opening angle and the accuracy of the intake and exhaust controls have been improved.

• The electric variable valve timing mechanism obtains higher response than the hydraulic variable valve timing mechanism. As a result, expansion of overlap and the closing timing of the intake valve are achieved.

Structural View

Structure

Operation

At engine start

• Engine startability has been improved by utilizing the features of the operable electric VVT even under the engine stop condition and controlling the optimal timing according to engine conditions.

Light/medium load range

• Pumping loss* is reduced by properly controlling the timing of intake and exhaust, improving the fuel consumption rate.

High load range

• By properly controlling the timing of the intake and exhaust and using the effect of scavenging residual gas in the cylinder and the inertia charging effect, the volumetric efficiency and the output are improved.