PitStopUSA.com - Valve Locks

Valve locks and retainers hold the retainer in place by using the force of the valve spring to hold the retainer and lock in place, not by the tang locking into the groove on the valve stem. In high performance or long endurance situations, 7° locks and retainers are much harder to disassemble from the spring and retainer. With higher racing valve spring pressures, 7° locks tend to work-weld themselves to the retainer. 10° locks and retainers were designed to help spread the load more and prevent the this issue making them the choice of engine builders for extreme high performance and racing applications. PitStopUSA.com recommends that you choose use hardened locks for high performance and race engine applications. For many street machine applications, 7° hardened locks are far more than adequate.