![]() ![]() This helps to increase engine’s breathing which also improves its ‘ volumetric efficiency’ to a large extent. At high speed, the Inlet valves open quite earlier so that more air-fuel mixture or ‘charge’ enters the cylinders. The VVT varies the timing of opening and closing of valves for multiple engine speeds. To overcome this deficiency, the engineers developed VVT or ‘Variable Valve Timing’ mechanism. However, as the engine speed increases, it considerably reduces the time required to fill the cylinders fully.As a result, the engine would receive less amount of charge (air-fuel mixture) which causes power-loss especially when the engine runs at high speed. In older conventional engines, the time for which the valves remained open was optimised only for single engine speed. This is because to produce more power, it needs to suck more air-fuel mixture (charge) for burning. Similarly, when the engine runs at high speed it needs to open its inlet valves earlier, faster & for a longer period. Thus, it causes faster breathing and/or wider opening of the mouth to receive more air. This is because when the human body is subjected to heavy work, it increases the need for air-intake. Besides, while carrying out activities like swimming or lifting a weight the persons also need to open the mouth to get more air. For e.g., if the person/s are sitting or sleeping, they will breath slowly as compared to when they are walking or running. The rate at which humans breathe mainly depends upon the work carried out by humans. Let’s try to understand in the begining, why to vary the Valve Timing/VVT?įirstly, read here first what is ‘ Engine valve-timing’? An automotive engine actually ‘breaths’ (inhales/exhales) thru’ its valves just like the humans do. ![]()
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