Engine Camshaft Bolt Lock Plate
Mr. Gasket 948G Cam Bolt and Lock Plate Kit for Chevy Small Block and Big Block
COMP Cams 5461 Camshaft Lock Plate with Bolts for GM LS Gen III/IV 3-Bolt Camshaft
Representative Photo, actual item may vary
Representative Photo, actual item may vary
What Is an Engine Camshaft Bolt Lock Plate?
An engine camshaft bolt lock plate is a small but critically important component found in the valve train of many performance and racing engines. Positioned at the front of the camshaft, the lock plate works alongside the camshaft retaining bolts to keep the timing gear firmly secured to the cam. Its primary job is to prevent the camshaft bolts from backing out under the vibration and mechanical stress that engines generate during operation — a problem that, if left unchecked, can lead to catastrophic valve train failure.
The mechanism is straightforward but highly effective. Once the camshaft bolts are torqued to specification, the lock plate's bendable tabs are folded up against the flats of the bolt heads, physically blocking them from rotating loose. This gives builders an extra layer of security that thread-locking compounds alone may not provide, especially in high-RPM or high-load applications.
Why the Camshaft Bolt Lock Plate Matters
In a street-driven vehicle, camshaft bolts rarely work themselves loose under normal operating conditions. However, in performance builds, engine rebuilds, or any application where the engine sees sustained high RPM and increased valve spring pressures, the risk of bolt loosening rises significantly. A camshaft bolt lock plate provides mechanical insurance that goes beyond friction and adhesive.
Beyond just securing the bolts, a lock plate also serves a secondary purpose in roller camshaft setups: it holds the cam button spacer in place, which controls camshaft end play. Forgetting this component in a roller cam build can result in unwanted cam walk and accelerated wear on the timing components.
Installation is accessible even for home builders. After aligning the plate's locating hole with the camshaft dowel pin, the bolts are threaded through the plate and into the cam, torqued in a cross pattern, and then the tabs are bent firmly against each bolt head. The result is a locked assembly that won't move — no matter what you throw at it on the strip or the street.
What to Look for When Shopping
- Material: Steel lock plates offer the durability needed to withstand high stress in racing and performance applications.
- Bolt count: Match the plate to your engine's cam bolt configuration — common options include 3-bolt patterns (popular in GM LS-series engines) and single-bolt designs for older small-block and big-block applications.
- Included hardware: Some kits include high-strength camshaft bolts along with the plate, ensuring you have everything needed for a complete installation.
- Application fitment: Always verify the lock plate is designed for your specific engine family, as cam bolt patterns vary widely across manufacturers and generations.
Top Brands in Engine Camshaft Bolt Lock Plates
Mr. Gasket is a legendary name in performance engine hardware with roots going back to the drag-racing world of the 1960s. Founded by racer Joe Hrudka, Mr. Gasket built its reputation supplying fasteners and sealing components that could withstand the demands of competition. Today, as part of the Holley Performance family of brands, Mr. Gasket continues to produce reliable valve train hardware — including camshaft bolt lock plates — trusted by enthusiasts building everything from classic muscle cars to modern performance engines.