🔍 Key Concepts

• Follow the label Z carefully to the exact part it touches, not just the general area. • Recall that a valve bridge is a solid mechanical piece that lets one rocker arm open two valves at the same time. • Use the color legend: exhaust vs scavenging air flows are shown in different colors in this cutaway.

💭 Think About

• Is label Z pointing to a sensor or instrument, or to a solid metal yoke sitting across two valve stems? • Is Z located on the exhaust side of the cylinder head or the air‑intake (scavenge/inlet) side? How can you tell from the gas‑flow colors? • Which of the choices describe a flow passage or opening, and which describe a mechanical linkage on top of the valves?

✅ Before You Answer

• Verify that Z is physically bridging two valve stems rather than attached to piping or wiring. • Check whether the passage beneath Z carries exhaust gas or scavenging air, using the color key on the drawing. • Confirm that an EGT monitor would normally be a probe in the exhaust stream, not a heavy machined part on top of the valve stems.