This specialized instrument is employed to precisely machine the area where the valve spring rests on the cylinder head. The purpose is to create a flat, consistent surface that ensures the valve spring sits squarely and maintains proper alignment. An example of its application includes modifying a cylinder head to accommodate higher performance valve springs with a larger diameter.
Ensuring correct valve spring installation is critical for engine performance and longevity. Precisely machined surfaces contribute to optimal valve train geometry, reducing stress on the valve spring and associated components. Historically, achieving this level of precision was a time-consuming manual process. The introduction of these tools significantly improved efficiency and accuracy.