Power:

Figure: Power

Both valves are blocked, and the fresh air charge has been compressed. The fuel has been injected and is starts to burn. After the piston passes TDC, heat is quickly released by the ignition of the fuel, causing an increment within cylinder pressure. A Combustion temperature is around 2336°F. That increment within pressure forces the piston downward and raise the force on the crankshaft for the power stroke as define in Figure.

The energy generates by the combustion process is not all harnessed. Within a two stroke diesel engine, only about 38 percent of the generates power is harnessed to do work, about 30 percent is wasted in the form of heat rejected to the cooling system, and about 32 percent in the form of heat is rejected out the exhaust. Within comparison, the four-stroke diesel engine has a thermal distribution of 42 percent converted to useful work, 28% heat rejected to the cooling system, and 30% heat rejected out the exhaust.