Question 93Motor Plants - 1st Asst/Chief

The correct answer is D) continue through the afterburning period. In a diesel engine, fuel combustion should begin just before the piston reaches top dead center and continue through the afterburning period. This allows for complete combustion of the fuel, maximizing the engine's efficiency and power output. The fuel injection is timed to start slightly before top dead center to allow for the ignition delay period, ensuring the fuel is fully combusted by the time the piston reaches top dead center. The other options are incorrect because: A) Fuel injection completion does not necessarily mark the end of combustion; B) Combustion should not be exactly completed at top dead center; and C) Combustion should not end at bottom dead center, as that would result in incomplete fuel burn.