How Many Types of Spark Plugs Are There?

[Catherine]

Spark plugs are mainly divided into the following types: standard spark plugs, extended insulator spark plugs, electrode spark plugs, seat spark plugs, pole spark plugs, and surface gap spark plugs. Spark plugs are installed on the side or top of the engine. In early designs, spark plugs were connected to the distributor via ignition cables. However, over the past decade, most car engines have been updated to feature direct connections between the ignition coil and the spark plug. Main types of spark plugs include: standard spark plugs, extended insulator spark plugs, electrode spark plugs, seat spark plugs, pole spark plugs, and surface gap spark plugs. Working principle of spark plugs: The ground electrode of a spark plug is connected to the metal shell, which is threaded into the engine block via the cylinder head. The insulator primarily serves to isolate the metal shell from the center electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and the center electrode, it ionizes the medium between the center electrode and the ground electrode, generating a spark to ignite the air-fuel mixture in the cylinder.