Spark Ignition Engines

Abstract

Spark ignition engines (based on the Otto cycle) have been developed since the late 19th century. Primarily used as a propulsion unit for vehicles, early design work was accelerated by the need for engines for military aircraft (only a few years after the first powered flight of the heavier than air machine) during the 1914–8 war. This resulted in a remarkable improvement in operating characteristics and reliability, and has been followed by stimuli such as the rapid growth of road transport and advanced aero-engine designs, first for civil aviation and later the military versions of the 1939–45 war. In the 1920–30s and since about the 1950s manufacturers have supported land, water, and air competitive racing which has stimulated advances in design and use of materials.