How Do the Spark Plugs Actually Works?

Most car owners know of spark plugs because they’re a common engine component that often needs to be replaced and are integral for an engine to work. Without them, the engine will not start. The electrical energy from the plugs is used to create a spark, which ignites the fuel-air mixture in the combustion chamber. 

Spark plugs are connected to high voltage— generated by an ignition coil or magneto. Current flows from the coil and a voltage develops between the central and side electrodes. But, fuel and air in the gap acts as an insulator and prevent an immediate fire. When the voltage exceeds the dielectric strength of the gases, the gases ionize— the gas then becomes a conductor, allowing the current to flow. The increase in the temperature of the spark channel causes the ionized gas to expand rapidly, which generates a small explosion.

The thermal performance of spark plugs indicates their heat range, or their ability to dissipate heat. On the firing end of a spark plug, the temperature must be high enough to prevent fouling but low enough to prevent pre-ignition. Cold spark plugs have a short heat flow path, which results in a quick rate of heat transfer; on the other hand, hot spark plugs have a longer heat transfer path, which results in a slower rate of heat transfer. It’s important to choose spark plugs that create optimal thermal performance. If the spark plug is too cold, it can cause carbon fouling and if it’s too hot, it can cause overheating.       

Although they are common components in an engine, they are not simple, and are made to be very precise. Their construction includes ribs, an insulator, the hex, shell, plating, gasket, threads, ground electrode, center electrode, spark park electrode gap, and an insulator nose.

At Aviation Sourcing Solutions, owned and operated by ASAP Semiconductor, we can help you find all the spark plugs and insulator parts you need, new or obsolete. For a quick and competitive quote, email us at sales@aviationsourcingsolutions.com or call us at 1-714-705-4780.