(Automotive engineering: Vehicle components, Engine, transmission, and exhaust) Pre-ignition is a situation in which the fuel-air mixture in a spark ignition engine ignites before the timed spark, because of contact with a hot surface. ▶ ignition1, ignition2, ignition3
⇒ Over-heated spark plugs and exhaust valves are the main causes of pre-ignition. ⇒ Pre-ignition might be the consequence of the spark plug tip getting too hot. ⇒ Thermal coatings also resist detonation and pre-ignition by keeping metal hot spots from forming on piston crowns or head chambers.
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