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 and the reforms of Cleisthenes at the end of the Archaic period brought in Athenian democracy as it was during the Classical period. In Sparta, many of the institutions credited to the reforms of Lycurgus were introduced during the period, the region of Messenia was brought under Spartan control, helotage was introduced, and the Peloponnesian League was founded, making Sparta a dominant power in Greece. The word "archaic" derives from the Greek word "archaios", which means "old". It refers to the period in ancient Greek history before the Classical. The period is generally considered to have lasted from the beginning