🔍 Key Concepts

• Valve lash (clearance) and how it affects valve timing • Relationship between smaller clearance and when the valve first touches the rocker/ cam lobe • Difference between timing (open/close events), lift, and duration of valve opening

💭 Think About

• Picture the cam lobe and rocker arm: if the clearance is smaller than designed, does the cam lobe contact the rocker earlier or later in its rotation? • Once contact is made earlier or later, think through what that does to both the opening moment and the closing moment of the valve during each cam rotation. • Decide which of the four options refers to when the valve opens/closes versus how far or how long it opens.

✅ Before You Answer

• Be clear on the definition of valve lash (cold clearance) and what happens to that clearance as the engine heats up. • Identify which options talk about timing (open later/close later) versus geometry (total lift, total duration). • Mentally compare a valve with too little clearance to one adjusted correctly: which one will have the cam lobe in contact with it for a longer portion of the rotation?