Pre-ignition for an automobile engine to continue on for thousands of kilometers with mild detonation, pre-ignition can destroy an engine in just a few strokes of the piston. Pre-ignition Pre-ignition (or preignition) in a spark-ignition engine is a technically different phenomenon from engine knocking, and describes the event wherein the air/fuel mixture in the cylinder ignites before the spark plug fires. Pre-ignition is initiated by an ignition source other than the spark, such as hot spots in the combustion chamber, a spark plug that runs too hot for the application, or carbonaceous deposits in the combustion chamber heated to incandescence by
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