Question 328Motor Plants - Assistant Engineer

The correct answer is D) pumping loss. The power consumed during the scavenging process of a diesel engine is known as the pumping loss. Scavenging is the process of expelling the exhaust gases from the cylinder and drawing in fresh air or air-fuel mixture. The work required to move the gases in and out of the cylinder is known as the pumping loss, which is a type of mechanical loss in the engine. The other answer choices are incorrect because: A) Compression loss refers to the power lost due to incomplete compression of the air-fuel mixture. B) Valve loss refers to the power lost due to the resistance to flow through the intake and exhaust valves. C) Back pressure loss refers to the power lost due to the resistance to the flow of exhaust gases.