Abstract: Valve clearance and valve lift are two important inspection items in engine valve-train. The scientificity of the online measuring method can comprehensively reflect the accuracy of the key indicators such as machining accuracy and assembly accuracy of the engine valve-train in the process of machining and assembly. Based on the analysis of the measurement methods of the two key parameters, the design characteristics of the measurement scheme and its significance to product quality control are studied. At the same time, it provides a reference for similar parts measurement selection scheme

Key words: valve clearance, valve lift, quality control