(Automotive engineering: Design and performance) Valve timing is the exact timing of the opening and closing of the valves in a piston engine. ▶ valve, timing
⇒ Carmakers have devised ways to change valve timing while the engine is running. ⇒ Variable valve timing offers the possibility of controlling the cylinder filling process solely by means
of restricting the opening of the inlet valve. ⇒ The intake valves rely on valve timing to open their ports at the correct time for the air and fuel ingredients.
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