What is the purpose of the tang on a valve lock?

The tang on a valve lock is primarily for temporary positioning. It helps locate the lock, retainer, and valve spring until the retainer's tapered surface creates a secure 'collet' effect that holds everything in place.

How do I know if these valve locks are the correct size for my valve stem?

When properly installed on the valve stem, there should be a small gap between the two halves of the lock. If the halves touch without a gap, they are too large. If they fit tightly to the stem and leave a gap between the middle of the lock and the stem's outer diameter, they are too small.

Are these valve locks suitable for high-performance engines?

These locks are recommended for street applications with lighter valve spring loads. They are not designed to withstand the very high spring loads found in many high-performance or racing engines.

COMP Cams Valve Lock 3/8in Single Groove 603-1

Name: COMP Cams Valve Lock 3/8in Single Groove
Brand: COMP Cams
Price: 6.95 USD
Availability: InStock

COMP Cams Valve Lock 3/8in Single Groove

$6.95

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

COMP Cams 3/8in single groove valve locks. A well-built replacement for stock engine rebuilds.

Key Features

Fits 171+ vehicle make/model combinations.
Hardened steel construction for durability.
Single groove design.
Features a 7-degree angle.
Designed for 3/8-inch valve stems.
Intended for street applications with lighter valve spring loads.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Will this fit your vehicle?

Product Details

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.