ABSTRACT
This chapter discusses the two most common reciprocating internal combustion (IC) engine types in current use: the spark ignition (SI) and the compression ignition (CI or Diesel) engines. It presents the fundamental theoretical background of IC engine function and performance, including four-stroke and two-stroke SI and CI engines. IC engines may be classified by a wide variety of characteristics; the primary category includes the type of ignition and the type of stroke. CI engines are produced in two-stroke and four-stroke versions. The actual operation of IC engines is idealized at a very basic level by the air standard power cycles. SI engines control power output by throttling the intake air. Brake work is the actual work produced at the output shaft of an engine, as measured by a dynamometer. Abnormal combustion may occur in SI engines associated with two combustion phenomena: knock and surface ignition.
