Ignition timing Ignition timing In a spark ignition internal combustion engine, Ignition timing refers to the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke. The need for advancing (or retarding) the timing of the spark is because fuel does not completely burn the instant the spark fires, the combustion gases take a period of time to expand and the angular or rotational speed of the engine can lengthen or shorten the time frame in which the burning and expansion should occur. In a
Archaic Greece of the eighth century BC until the beginning of the fifth century BC, with the foundation of the Olympic Games in 776 BC and the Second Persian invasion of Greece in 480 BC forming notional start and end dates. The Archaic period was long considered to have been less important and historically interesting than the Classical period, and was primarily studied as a precursor to it. More recently, however, Archaic Greece has come to be studied for its own achievements. With this reassessment of the significance of the Archaic period, some scholars have objected to the term "archaic", due to