The give or play in the valve train before the cam starts to open the valve is called

The give or play in the valve train before the cam starts to open the valve is called

• A. Valve lash
• B. Valve clearance
• C. Valve gap
• D. Valve timing variance

Answer: (A)

Valve lash is the small amount of free play in the valve train when the valve is fully closed and the cam has not yet begun to lift the valve. That slack lets the parts move freely and accommodates heat expansion, wear, and manufacturing tolerances. As the cam lobe starts to push, it first takes up this slack before the valve actually opens. This is why the term valve lash describes the “give” before opening. If lash is too tight, components can bind or the valve may not seal properly as everything expands with heat; if lash is too loose, the valve may chatter and the opening timing become imprecise. Valve clearance is related terminology, but the precise name for this specific free play is valve lash, while valve gap and valve timing variance aren’t standard terms for this phenomenon.

Valve lash is the small amount of free play in the valve train when the valve is fully closed and the cam has not yet begun to lift the valve. That slack lets the parts move freely and accommodates heat expansion, wear, and manufacturing tolerances. As the cam lobe starts to push, it first takes up this slack before the valve actually opens. This is why the term valve lash describes the “give” before opening. If lash is too tight, components can bind or the valve may not seal properly as everything expands with heat; if lash is too loose, the valve may chatter and the opening timing become imprecise. Valve clearance is related terminology, but the precise name for this specific free play is valve lash, while valve gap and valve timing variance aren’t standard terms for this phenomenon.