🔍 Key Concepts

• Study the internal passage shown in Fig. A and trace where it opens into the cylinder space. • Compare the detailed ends in Fig. B and Fig. C with what you know about fuel valves, starting‑air valves, and indicator cocks. • Think about which device must withstand and transmit combustion pressure without significantly changing engine operation.

💭 Think About

• Does this device appear to have large-flow ports like a starting air valve or small passages suitable for measurement or injection? • If you connected a gauge or indicator to the outer end, what would you be trying to observe inside the cylinder? • Which of the listed functions (air, lube, fuel, or pressure reading) can be done through a long, narrow, centrally bored passage as shown?

✅ Before You Answer

• Verify where the inner end of the passage (near label 11/12) actually opens relative to the combustion chamber. • Check whether there is a check valve or spring‑loaded element (see Fig. B and Fig. C) that would protect an external instrument from combustion pressure. • Confirm whether the construction resembles a normal fuel injector/nozzle assembly, a lube quill, or a small port for attaching indicator/pressure equipment.