Spark Plugs In A Petrol Engine

Spark plugs in a petrol engine

A spark plug is used in internal combustion engines to create a spark in the cylinder and ignite the fuel in the combustion chamber allowing the engine to rotate. The common spark plug has come a long way in development over the years.

The basic operation of a spark plug is very simple. Is it made up as a compact source of ignition. The individual components are as follows: the terminal or tip- this is the part of the spark plug that the ignition wires or coils make contact with, the insulator- normally made of porcelain and developed to provide mechanical support to the centre electrode while also insulating the electrical current going through the plug, the ribs- these are built in to the insulator used to lengthen the surface between the high voltage terminal and the grounded metal case of the plug itself, the design also helps prevent electrical energy from leaking along the insulator surface, the insulator tip- this is the part of the plug that protrudes into the combustion chamber, this is designed to withstand the extreme temperatures while retaining electrical insulation, it also must retain thermal conductivity to do its job properly, the seal- between the ceramic centre and the metal casing this is normally a multi layered braze to stop any leakage, the metal case- also known as the jacket, this is the part of the spark plug that screws into the cylinder head the threads are made of steel and acts as an electrical ground for the plug itself, the centre electrode- the electrode is the working part of any spark plug, it carries current from the ignition wire down the length of the electrode and allows the plug to spark across the gap between the electrode to the ground tab of the casing allowing the ignition of the fuel in the combustion chamber. Read  More