Spark Plug
A spark plug is installed to every cylinder, between the intake and exhaust valves. An ignition coil is installed on each spark plug. The spark plug is a device for delivering electric current from the ignition system to the combustion chamber. The spark plugs feature an Iridium tipped center electrode, and a platinum tipped ground electrode.
The spark plug is connected to the secondary winding within the ignition coil. As the current flows from the coil, a voltage develops between the center and ground electrodes. When the voltage differential equals the required voltage, then the spark plug produces a spark and the stored energy within the ignition coil is dissipated.