Measurement of the exact instant when the valves open or close in an internal-combustion engine, or when the spark occurs. It is normally expressed in degrees or millimetres before TDC (see ignition timing and port timing).
Measurement of the exact instant when the valves open or close in an internal-combustion engine, or when the spark occurs. It is normally expressed in degrees or millimetres before TDC (see ignition timing and port timing).