COMP Cams Valve Lock 3/8in Single Groove

When you're rebuilding the top end of an engine, getting the valve train components right is crucial. These COMP Cams valve locks are designed as a direct replacement for stock applications, especially if you're working on a street-driven vehicle with lighter valve spring loads. They feature a 7-degree angle and are made for a 3/8-inch valve stem size, which is a common size for many American-made engines from the 60s, 70s, and 80s, fitting a wide range of vehicles like Chevrolet Bel Airs, AMC Hornets, and many others.

It's important to ensure these locks fit correctly. When properly installed, there should be a small gap between the two halves of the lock once they're seated on the valve stem. If the halves butt up against each other without a gap, they're too large. The tang on the lock's side isn't what holds everything together under high spring pressure; instead, it just helps position the lock and retainer until the retainer's tapered surface creates a collet effect, securely binding the lock and retainer. This design means the more spring force applied, the tighter the lock holds.