Coast Guard Exams
Question 108Motor Plants - Assistant Engineer70% to pass

In the diesel engine illustrated, what part is under compression when firing is taking place in a particular cylinder? Illustration MO-0003

Diagram for question 108
AI Explanation
The correct answer is D) Piston rod. When firing is taking place in a particular cylinder, the piston is under compression. The piston rod, which is connected to the piston, is the part that transmits the force generated by the combustion of the fuel-air mixture to the crankshaft, causing the engine to rotate. The other answer choices, such as the tie rod, piston rod nut, and lubrication telescopes, are not directly involved in the compression and power stroke of the cylinder during the firing process.