5. 3 Diesel Engines Fuel injector The diesel engine is an internal combustion 凸 (starting aid) engine similar to the gasoline engine Prechamber Exhaust valve Difference: Diesel engine does not use electric spark ignition and it does not mix the Intake valve Combustion fuel and air before admitting them to the combustion chamber During the compression stroke, the diesel combustion chamber contains only air The pressure can reach as high as 15 atm and the temperature of the compressed air has been increased to the ignition point for a fuel-air mix A short burst of fuel is injected into the chamber The fuel mixes with the hot air and immediately Figure 3.10 Cutaway drawing of a ignites without the help of an electric spark. diesel engine. Ignition is accomplished by the high temperature produced by the compressed of air5.3 Diesel Engines Figure 3.10 Cutaway drawing of a diesel engine. Ignition is accomplished by the high temperature produced by the compressed of air. The diesel engine is an internal combustion engine similar to the gasoline engine. Difference: Diesel engine does not use electric spark ignition and it does not mix the fuel and air before admitting them to the combustion chamber. • During the compression stroke, the diesel combustion chamber contains only air. • The pressure can reach as high as 15 atm and the temperature of the compressed air has been increased to the ignition point for a fuel-air mix. • A short burst of fuel is injected into the chamber. • The fuel mixes with the hot air and immediately ignites without the help of an electric spark