🔍 Key Concepts

• Crankpin bearing lubrication path and how oil reaches the crankpin and piston components • Relationship between connecting rod alignment and wear patterns on bearings and piston skirts • Difference between problems caused by lubrication failures vs mechanical misalignment

💭 Think About

• If oil flow to the crankpin were blocked, which parts would you expect to show the first and most severe damage? • What kind of problem would cause the piston to side-load more heavily on the cylinder wall, changing the wear pattern on the piston skirt? • Would high firing temperatures normally affect the crankpin bearing and piston skirt directly, or other components first (like valves, piston crowns, rings)?

✅ Before You Answer

• Match the specific locations of wear (crankpin bearing AND piston skirt) to a single common cause • Ask whether each choice would mainly cause heat-related damage, air/fuel issues, or alignment/lubrication issues • For each option, visualize the force path from crankshaft → crankpin → connecting rod → piston and decide where misalignment would show up as abnormal wear