Pre-ignition for an automobile engine to continue on for thousands of kilometers with mild detonation, pre-ignition can destroy an engine in just a few strokes of the piston. Pre-ignition Pre-ignition (or preignition) in a spark-ignition engine is a technically different phenomenon from engine knocking, and describes the event wherein the air/fuel mixture in the cylinder ignites before the spark plug fires. Pre-ignition is initiated by an ignition source other than the spark, such as hot spots in the combustion chamber, a spark plug that runs too hot for the application, or carbonaceous deposits in the combustion chamber heated to incandescence by
Ignition timing these engines will also use a vacuum advance that advances timing during light loads and deceleration, independent of the centrifugal advance. This typically applies to automotive use; marine gasoline engines generally use a similar system but without vacuum advance. In mid-1963, Ford offered transistorized ignition on their new 427 FE V8. This system only passed a very low current through the ignition points, using a PNP transistor to perform high-voltage switching of the ignition current, allowing for a higher voltage ignition spark, as well as reducing variations in ignition timing due to arc-wear of the breaker points. Engines so equipped