Is Ignition Advance Angle the Same as Ignition Timing?

[AlejandroLee]

Ignition advance angle and ignition timing are not the same. The ignition advance angle refers to the angle through which the crankshaft rotates from the moment the spark plug fires (before the engine piston reaches the top dead center of compression) until the piston reaches the top dead center of compression. Ignition timing, on the other hand, occurs at the end of the engine's compression stroke when the piston reaches the top of its stroke. At this moment, the ignition system provides a high-voltage spark to the spark plug to ignite the compressed air-fuel mixture in the cylinder, and this time is known as ignition timing. Factors affecting the engine's ignition advance angle include: 1. Engine speed; 2. Load; 3. Octane rating; 4. Combustion chamber shape; 5. Temperature inside the combustion chamber; 6. Air-fuel ratio; 7. Atmospheric pressure; 8. Coolant temperature.