Internal (ignition)Combustion Engines Spark ignition (SD: combustion initiated by spark air and fuel can be added together Light and lower in cost,used in automobiles Compression ignition (CD: combustion initiated by auto ignition requires fuel injection to control ignition large power,heavy trucks,locomotives,ships 上游通大学 Monday,May 08,2017 8 SHANGHAI JLAO TONG UNIVERSITYMonday, May 08, 2017 8 Internal (ignition) Combustion Engines Spark ignition (SI): • combustion initiated by spark • air and fuel can be added together • Light and lower in cost, used in automobiles Compression ignition (CI): • combustion initiated by auto ignition • requires fuel injection to control ignition • large power, heavy trucks, locomotives, ships