COMP Cams 629-100 - Machined Steel Set of 100 - 7 Degree, 5mm, Single Groove Race Locks

Most people believe that the tang inside a valve lock holds the retainer and valve spring in place while the engine is running, but this isn't the case. The cross-section of material in the tang is not strong enough to withstand open spring loads of 1000 lbs. or more. The sole purpose of the tang is to temporarily locate the lock, retainer and spring relative to the valve until the taper of the retainer can nest around the outside surface of the lock. This creates a collet effect that binds the two together. The more spring force exerted on the retainer (as the valve opens), the more force applied by the collet effect to keep the retainer and lock in place. With the emergence of valve sizes other than the standard 5/16", 11/32" and 3/8", it is important to make sure the valve locks match the valve size. There should always be a small gap between the two halves of the lock when they are properly positioned on the valve stem. If the two halves fit together without a gap, they are too large. If the locks fit