You are about to perform valve stem to...

Study

Question 1 of 2066636eef28f7522a1c520063

You are about to perform valve stem to rocker arm clearance adjustments on an auxiliary diesel engine onboard your offshore supply vessel. Which of the following statements concerning hot and cold clearances is true?

Back

Question 1 of 20

66636eef28f7522a1c520063

No comments yet

Be the first to share your thoughts!

If the question has a related picture, it will appear here.

🔍 Key Concepts

• Thermal expansion of metals in engine components (valve, pushrod, rocker arm, cylinder head, block) • Purpose of valve lash (valve clearance) in a diesel engine and what happens if it becomes too tight or too loose • Difference between adjusting valves on a cold engine vs. checking/setting "hot" running clearances

💭 Think About

• Mentally trace the path from the camshaft to the valve tip. Which parts get the hottest and expand the most when the engine reaches operating temperature? • If all those parts lengthen or move as the engine heats up, what happens to the gap (lash) between the valve stem and rocker arm—does it tend to open up or close up? • Think about why manufacturers usually give a cold setting in the manual. Is that cold setting chosen so that the running (hot) clearance will be a specific value?

✅ Before You Answer

• Verify how thermal expansion affects the length of the valve stem compared with the height of the cylinder head and the valve train geometry. • Check in a typical engine manual whether cold lash is usually set slightly different from the hot running lash, and in which direction that difference lies. • Confirm the basic safety reason for lash: the valve must fully close at operating temperature; consider whether too-small hot clearance or too-large hot clearance is the bigger danger.

👋 Hi! I'm Genie, your AI study assistant. How can I help you with this question?

Quick actions

— No credit card needed