Setting Valve Spring Heights

As noted in Setting Stem Heights, when grinding the valve seat and valve face, the valve spring installed height will be increased a corresponding amount. The use of different retainers/rotators as well as valves with different keeper heights will also effect the valve spring installed height. For maximum performance, valve spring installed heights must be set to the manufactures specifications. Valve springs are designed to provide a specified pressure at a given installed height. When this height is altered due to the valve grinding process, the springs will no longer provide the proper tension. Thus limiting the engine rpm capability. It is also important to use valve springs that match the camshaft profile.

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