Performance Spark Advance CONTROLLING IGNITION TIMING DELAYS

摘要

In a spark ignition internal combustion engine, the purpose of advancing the timing of the engine spark is to get past ignition delay. Ignition delay occurs during the time that it takes to fully ignite the mixture with a spark plug. That is typically 15-35 degrees before TDC (top dead center) of the power stroke depending on the engine speed. Best power is achieved when ignition timing is set to fire the spark ahead of time to reach that peak pressure at about 2 degrees after TDC. This is done with a combination of initial advance, plus centrifugal or electronic controlled advance for engine speed, plus vacuum or electronic advance for engine loading and throttle effect.