🔍 Key Concepts

• Lubrication systems on modern medium- and high-speed diesel engines • Difference between splash, gravity, and pressure lubrication • How oil reaches crankshaft main bearings and connecting rod big-end bearings

💭 Think About

• Think about whether bearings inside a fast-rotating crankshaft can rely on oil simply running down or being thrown around, or if they need something more forced and reliable. • Consider which system allows oil to be delivered through internal drillings/passages in the crankshaft to the connecting rod bearings. • Ask yourself: on a large modern marine diesel, what happens to lubrication if engine speed changes—would some methods become unreliable?

✅ Before You Answer

• Identify which method is normally used for heavily loaded, high-speed bearings like crankshaft mains and connecting rod big ends. • Eliminate any methods that depend mainly on chance contact with oil rather than a controlled supply. • Confirm which system typically uses an engine-driven oil pump to force oil through galleries and drilled passages.