An automobile self-starter
(commonly "starter motor" or simply "starter") is an electric motor that
initiates rotational motion in a car's internal combustion engine before
it can power itself.
A spark plug is an electrical device also called
auto parts that fits
into the cylinder head of some internal combustion engines and ignites
compressed aerosol gasoline by means of an electric spark.
Spark plugs have an insulated
center electrode which is connected by a heavily insulated wire to an
ignition coil or magneto circuit on the outside, forming, with a
grounded terminal on the base of the plug..
Early patents for spark plugs included those by Nikola Tesla, Richard
Simms (GB 24859/1898,1898) and Robert Bosch (GB 26907/1898).Some
historians have reported that Edmond Berger invented an early spark plug
on February 2, 1839. Karl Benz is also credited with the invention. But
only the invention of the first commercially viable high-voltage spark
plug as part of a magneto-based ignition system by Robert Bosch's
engineer Gottlob Honold in 1902 made possible the development of the
internal combustion engine.
Internal combustion engines can be divided into spark-ignition engines,
which require spark plugs to begin combustion, and compression-ignition
engines (diesel engines), which compress the air and then inject diesel
fuel into the heated compressed air mixture where it auto ignites.
Compression-ignition engines may use glow plugs to improve cold start
Spark plugs may also be used in other applications such as furnaces
where a combustible mixture should be ignited. In this case, they are
sometimes referred to as flame igniters.
Spark plug construction
A spark plug is composed of a shell, insulator and the conductor. It
pierces the wall of the combustion chamber and therefore must also seal
the combustion chamber against high pressures and temperatures, without
deteriorating over long periods of time and extended use.