Which lubrication method employs a spray nozzle to lubricate the piston pin?

• A. Drilled passages in the connecting rod
• B. Spray nozzle
• C. Splash oil from the crankcase
• D. Oil bath in the cylinder

Answer: (B)

The idea being tested is targeted lubrication of the piston pin using a spray nozzle. A spray nozzle system atomizes oil and projects it directly onto the wrist pin area, creating a consistent film that reduces wear and cools the pin at high engine speeds. This direct, controllable spray is what sets it apart from other methods. Drilled passages in the connecting rod deliver oil through internal channels, but not as a spray directed at the pin. Splash oil from the crankcase relies on oil being thrown around by motion, which is less precise for the pin area. An oil bath in the cylinder places oil elsewhere in the cylinder, not at the pin interface. So the spray nozzle approach specifically provides the direct, localized lubrication the piston pin needs.