Preignition

Preignition – Definition and Causes

Preignition is an occurrence in internal combustion engines where ignition takes place before the normal ignition timing. It is a harmful phenomenon that can cause damage to the engine and decrease its efficiency.

Preignition is commonly caused by a hot spot in the combustion chamber that ignites the fuel-air mixture before the spark plug fires. This condition creates a sudden and uncontrolled increase in pressure and temperature, leading to engine knocking. The knocking sound is a result of the forceful collision of the burning and unburnt fuel-air mixture and the resulting shock waves.

Preignition can occur due to several reasons, such as excessive carbon deposits in the combustion chamber, overheating, or incorrect fuel octane rating. As a preventive measure, it is crucial to maintain the engine’s components clean and in good condition, control the engine’s temperature, and use the recommended fuel grade.

In summary, preignition refers to an early ignition process in internal combustion engines, causing engine knocking, decreased performance, and damage. It can occur due to various reasons, and preventing it involves regular engine maintenance and using the recommended fuel grade.