🔍 Key Concepts

• Cylinder liner wear patterns in medium and slow-speed diesel engines • Relationship between liner wear and piston ring / ring groove contact and motion • Where in the stroke the gas pressure, temperature, and side thrust are highest

💭 Think About

• Think about where the piston rings change direction and gas pressure is greatest in the cylinder. Would that area see more or less wear than the middle or bottom of the stroke? • If the liner wears excessively but evenly all around, how does that affect how tightly the ring fits between the liner and the groove? Does it increase or decrease rubbing in the groove? • Which statements, if true, would logically contradict normal diesel engine practice and observed wear patterns in real engines?

✅ Before You Answer

• Check which option correctly reflects that liner wear is not uniform along the stroke in most diesel engines. • Consider whether excessive wear tends to increase or decrease the tendency for ring and groove to rub and hammer against each other. • Eliminate any choice that assumes liner wear is equal top to bottom or greatest where loads are actually lowest.