SERIES 60 SERVICE MANUAL FOUR CYCLE PRINCIPLE FOR NATURAL GAS ENGINES This engine is a four cycle internal combustion engine, in which the energy of burning fuel is converted into energy to work the cylinder of the engine. However, unlike the diesel engine, a combustible air and fuel mixture is introduced to the cylinder during the intake stroke. Upon compression, the temperature of this mixture is increased to a temperature below its auto-ignition threshold. Combustion occurs through means of a spark plug which ignites the mixture. See Figure 2 for the four stroke cycle utilized on the natural gas engine. Figure 2 The Four Stroke Cycle (Series 60G Engine) (Rev.
2005) All information subject to change without notice. 6 6SE483 0507 Copyright © 2005 DETROIT DIESEL CORPORATION