What part of the valve can be ground down to restore valve stem height specifications?

• A. The valve stem
• B. The valve face
• C. The retainer
• D. The valve tip

Answer: (D)

When you need to bring valve stem height back into spec, you adjust by removing small amounts from the end of the valve—the tip. Shortening the tip reduces the overall valve length so the distance between the stem and the rocker/cam contact point returns to the correct value, without altering the seat geometry or the stem’s diameter. Grinding the stem would weaken it and alter its fit; grinding the valve face would change the seating surface; grinding the retainer would affect spring seating and mass. So the valve tip is the right surface to grind to restore stem height.