A tool used to determine the force exerted by a valve spring at specific points of its compression range. These points typically include the installed height (spring compressed to its operational length when installed on the cylinder head) and the maximum lift height (spring compressed to the extent determined by camshaft lobe lift). The calculation involves considering factors like spring rate, free height, installed height, and valve lift.
Accurate assessment of spring force is crucial for optimal engine performance and reliability. Insufficient force can lead to valve float, a condition where the valve fails to follow the camshaft lobe profile, resulting in power loss and potential engine damage. Excessive force, conversely, can cause premature wear on valve train components such as the camshaft, lifters, and valve seats. Historically, determining these values required manual measurements and calculations, prone to error and time-consuming. Modern tools streamline this process and improve accuracy.