🔍 Key Concepts

• Examine the cylinder head area closely to locate the valve stems, guides, and seats in cross‑section. • Think about normal medium‑speed diesel engine practice: which parts are usually made as separate inserts so they can be renewed without replacing the whole cylinder head? • Notice how the drawing shows different materials or pieces where components are pressed or shrunk into the head casting.

💭 Think About

• In the cross‑section, can you see small cylindrical pieces around the valve stems that appear as separate from the main head casting? What does that suggest about the valve guides? • Around the valve face, do you see a distinct ring set into the head, or does the seating surface appear to be machined directly in the parent metal? How would that affect replacement in service? • If an engine is expected to run hot and for long hours, which is more likely to be designed as easily replaceable: the part guiding the valve stem, the seating surface, or both? Why?

✅ Before You Answer

• Identify on the illustration exactly where the valve guide is and decide if it looks like a separate sleeve or part of the casting. • Identify the valve seat contact area and check whether there is a separate ring drawn between the head and the valve or just one continuous metal piece. • Before choosing, eliminate any option that conflicts with what you can clearly see in the cross‑section: whether the guide and seat each appear as separate inserts or integral with the head.