🔍 Key Concepts

• Relationship between combustion (firing) pressure and forces transmitted through the piston, connecting rod, and crankshaft • Difference between steady loads (like rotating/centripetal forces) and peak cyclic loads in a diesel engine • How main bearings support the crankshaft and what kind of force passes through them during each power stroke

💭 Think About

• When the fuel burns in the cylinder, what direction is the resulting force, and how does it travel down to the crankshaft main bearings? • Between inertia, centripetal, axial, and firing forces, which one changes most sharply in magnitude during each power stroke? • Think about when a main bearing is most stressed: is it during simple rotation, or during the moment of maximum cylinder pressure?

✅ Before You Answer

• Be clear on what axial load means versus a radial load on the main bearing • Consider which load is directly caused by combustion pressure rather than by motion or rotation of parts • Ask: which of these loads would create the highest peak force on the crankshaft main bearings during normal engine operation?