🔍 Key Concepts

• How heat is removed from a diesel piston during operation • What happens when insulating deposits (like carbon or sludge) build up on metal surfaces • The relationship between piston cleanliness and lubrication/temperature control

💭 Think About

• Think about the main path for carrying heat away from the underside of a piston—what fluid is there and how does it work? • If a layer of sludge builds up between the piston metal and the cooling/lubricating medium, how would that affect heat transfer? • Which option best describes a direct physical result of poorer heat transfer at the piston underside, rather than a chemical or secondary effect?

✅ Before You Answer

• Identify which choice is a direct thermal effect on the piston itself, not on the gases or oil mixture • Ask yourself which option would most likely result from a loss of efficient heat conduction through the piston crown • Eliminate any answer that depends on chemical reaction more than basic heat-transfer and insulation principles