Combustion requires three elements – fuel, air and an ignition source. Air is a no-brainer, being available pretty much wherever drivers are. For most of the history of the automobile, we’ve mainly relied on some form of refined petroleum as the fuel. Like most other aspects of motorized transportation, the method of lighting off the air-fuel mixture has evolved with technology.
The internal combustion engines in the vast majority of vehicles over the past 127 years have used one of two basic ignition types; spark or compression, with the spark plug being dominant. Regardless of the ignition source, if an engine has pistons or rotors and two-strokes or four, some basic principles are common. Air and fuel are drawn into the combustion chamber, compressed, burned and then expelled… read more >