🔍 Key Concepts

• Basic operation of a two-stroke diesel engine (how air and exhaust normally flow) • Difference between ports in the cylinder liner and valves in the cylinder head • What must leave the cylinder through the head after combustion

💭 Think About

• In a typical large marine two-stroke, does fresh air usually enter through ports in the liner or through valves in the head? • What actually passes through the cylinder head right after the power stroke is completed? • Of the listed options, which flow is most commonly controlled by valves located in the head on a uniflow-scavenged two-stroke diesel?

✅ Before You Answer

• Remember that many large marine two-strokes use scavenge air ports in the cylinder liner, not intake valves in the head • Identify what gas or fluid still needs a path out of the cylinder after combustion is finished • Verify which of the listed flows is normally associated with a valve in the cylinder head rather than ports or separate piping elsewhere