🔍 Key Concepts

• Compare visual clues in the cylinder and valve area to what you know about two-stroke vs four-stroke diesel construction. • Look closely at how the fuel injectors and valve gear are driven in the cylinder head area. • Ask yourself which options describe features that can actually be seen in a sectional drawing, versus those that are mostly about system design or operation.

💭 Think About

• In the illustration, what do you see around the cylinder walls: are there scavenge/exhaust ports in the liner, or only poppet valves in the head? What does that suggest about the engine cycle? • Can you trace any mechanical linkage from a camshaft or rocker arm directly to the injectors or valves? Which of the answer choices talks about something that would be visible in that area? • Which choices describe characteristics (like the type of turbocharging system) that would be hard to confirm from a single cross-section, and which describe hardware that should be clearly identifiable?

✅ Before You Answer

• Identify whether there are ports in the cylinder liner (typical of many two-stroke engines) or just valves in the cylinder head. • Check if the injectors appear to be cam-actuated in the head (unit injectors) or if there are separate high‑pressure fuel lines leading to them from a pump. • Look for adjusting screws or nuts on the rocker arms over the valves, which would indicate a particular method of setting valve lash.