Pic. 2.29. Diagram of the valve timing mechanism: 1 - torque; 2 – engine speed; 3 - low and medium speed engine; 4 - high-speed engine; 5 - engine with a mechanism for changing the valve timing
The variable valve timing mechanism ensures the optimum opening and closing of the valves according to the operating conditions of the engine by continuously changing the timing of the intake camshaft and crankshaft (pic. 2.29).