🔍 Key Concepts

• Scavenging air space location and function in a slow-speed diesel engine • Typical sources of local overheating inside or near the scavenging space • How blow-by and fuel timing affect where heat and combustion actually occur

💭 Think About

• First, picture exactly where the scavenging air space is in relation to the piston, liner, and crankcase. Which listed problem occurs closest to that area? • Which option would most likely create a hot spot or ignition source directly in the scavenging air space, not just in the cylinder or crankcase? • Think about which fault would allow hot gases or burning particles to enter the scavenging air space and ignite any oil that has accumulated there.

✅ Before You Answer

• Be clear on what scavenging air space is (under piston vs in cylinder vs crankcase). • Identify which choices mainly affect crankcase bearings, which affect exhaust flow, and which affect ring pack and ports. • Ask: which fault could let hot combustion products or very hot surfaces occur right where lube oil or unburned oil can collect in the scavenging air space?