Question 5Motor Plants - 1st Asst/Chief

The correct answer is D) Pores in the plating aid in maintaining the lube oil film. The porous chromium plating on the cylinder liner wearing surface helps maintain the critical lubrication oil film between the liner and piston rings. The porous nature of the chromium provides tiny reservoirs that can hold and release small amounts of lubricating oil, ensuring a continuous film is maintained. This prevents direct metal-to-metal contact, which would lead to excessive wear and eventual failure of the engine components. The other answer choices are incorrect because: A) The chromium plating does not specifically prevent wear on the piston rings, B) the chromium is not added to strengthen the liners around the scavenging ports, and C) the chromium plating does not eliminate the need for oil scraper rings, which serve a different purpose in the engine.