What Are the Main Factors Affecting Ignition Timing Advance?

[Harris]

Here are the main factors affecting ignition timing advance: 1. Cylinder temperature and pressure: The higher they are, the faster the combustion, requiring a smaller ignition timing advance. Factors influencing cylinder temperature and pressure include engine compression ratio, ambient temperature, cylinder temperature, and load. 2. Gasoline octane number: The higher the gasoline grade, the stronger its anti-knock capability, allowing for a larger ignition timing advance. 3. Air-fuel mixture ratio: Both overly rich and lean mixtures burn slower, necessitating an increased ignition timing advance. This depends on throttle opening and altitude. 4. Engine speed: As speed increases, the time to rotate the same angle decreases, requiring a larger advance angle to achieve the corresponding advance time.