🔍 Key Concepts

• How valve clearance (lash) affects when the cam actually starts to move the valve • Relationship between less clearance and the cam lobe taking up slack sooner or later • Whether cam profile or clearance determines total valve lift and duration

💭 Think About

• If you make the clearance smaller, does the cam start moving the valve sooner or later in its rotation? How does that affect opening time? • Once the clearance is reduced, will the valve finish closing earlier or later in the cam rotation? What does that do to how long it stays open? • Does changing clearance actually change the maximum lift of the valve, or mostly the points where it begins to open and finally closes?

✅ Before You Answer

• Be clear whether less clearance = less slack, and what that means for when motion is transmitted from cam to valve. • Decide whether lift is controlled mainly by the cam lobe shape or by the clearance setting. • Think through whether a valve that starts opening earlier will also tend to close later, and what that implies about open duration.