How Do You Change Installed Height, and What Effect Does it Have?

The easiest way to lessen installed height is to insert a shim in the spring pocket below the valve spring. Another method is to use a different design valve spring retainer. Retainers with a deeper dish will have more installed height; with a shallower dish, less installed height. You can also use a valve lock that is designed to change the location where the retainer is positioned on the valve stem. Longer length valves can also be used.

The shorter the installed height, the higher the valve spring tension will be, and the less distance the spring can travel before reaching coil bind.

The taller the installed height, the less the valve spring tension and the further the spring can travel before coil bind occurs.