🔍 Key Concepts

• Valve lash (tappet clearance) on an overhead valve engine • Where valve clearance is actually measured versus where it is adjusted • The difference between a contact point (rocker-to-valve tip) and a pivot/fulcrum (rocker support)

💭 Think About

• On this style of rocker arm, at what exact interface does the clearance (lash) physically exist when the valve is closed? Look carefully at labels C and D. • Which component typically has the locknut/adjusting screw for setting clearance: the pushrod end, the valve tip end, or the rocker pivot? Match that to labels A, B, and E. • Would ‘normal maintenance’ more likely involve changing a fixed geometry part (like the valve stem itself) or checking/setting a designed clearance with a feeler gauge?

✅ Before You Answer

• Identify which two labeled points come apart and come together as the valve opens and closes, creating the tappet (lash) gap. • Confirm which labeled point appears to be an adjusting screw with a locknut, versus a simple contact surface. • Recall that routine maintenance on valve gear usually means checking and setting valve clearance (lash), not re-machining or altering major parts.