Combustion Chamber Deposits in Spark-Ignition Engines: A Literature Review

Deposits derived primarily from the fuel but with some contribution from the oil are formed on all internal surfaces of a spark-ignition engine. Interest in combustion chamber deposits (CCD) has increased as fuel and additives technology to control deposits in other parts of the engine has matured. This paper reviews the literature on CCD. It discusses the mechanisms involved in the growth of CCD, their properties and structure, the engine and fuel-related factors that influence their growth and finally the effects of CCD on engine performance and emissions.