Installing Cam Bearings on a Small Block Chevrolet Engine: A Comprehensive Guide

Installing cam bearings is a critical step in rebuilding or modifying an engine. Accurate and precise installation ensures proper camshaft operation and longevity. This article provides a comprehensive guide to installing cam bearings on a small block Chevrolet (SBC) engine. It covers the tools and materials needed, step-by-step instructions, troubleshooting tips, and common mistakes to avoid.

Tools and Materials

Before starting, gather the following tools and materials:

Step-by-Step Installation

1. Remove Freeze Plugs

• Using a freeze plug punch, carefully tap out the 8 freeze plugs from the cam bearing bores.

2. Clean Cam Bearing Bores

• Use a clean rag and solvent to thoroughly clean the cam bearing bores of any debris or dirt.
• Allow the bores to fully dry.

3. Measure Cam Bearing Bores

• Use a micrometer or dial caliper to measure the diameter of each cam bearing bore.
• Record the measurements for later reference.

4. Measure Cam Bearing Clearance

• Measure the outer diameter of the cam bearing using a micrometer or dial caliper.
• Calculate the bearing clearance by subtracting the cam bearing diameter from the cam bearing bore diameter.
• Target bearing clearance for SBC engines is typically 0.0015-0.0025 inches.

5. Install Cam Bearings

• Lubricate the cam bearing bores with assembly lubricant.
• Apply a thin layer of assembly lubricant to the outer surface of the cam bearings.
• Use a cam bearing driver to press the cam bearings into the bores flush with the block surface.
• Take care to align the cam bearing oil holes with the oil passages in the engine block.

6. Install Freeze Plugs

• Lubricate the freeze plugs with assembly lubricant.
• Press the freeze plugs into the cam bearing bores until they are flush with the block surface.

Tips and Tricks

• Use a quality cam bearing driver to ensure the bearings are installed straight and evenly.
• Lubricate all bearing surfaces to minimize friction and heat during engine operation.
• Double-check the bearing clearance measurements to ensure they meet specifications.
• If the bearing clearance is too tight, it can cause excessive wear and friction. If the clearance is too loose, it can result in camshaft noise and premature failure.
• Take your time and follow the instructions carefully. Installing cam bearings improperly can lead to engine damage.

Common Mistakes to Avoid

• Installing Cam Bearings Backwards: The oil holes in the cam bearings must align with the oil passages in the engine block. Installing the bearings backwards can block oil flow and cause premature camshaft failure.
• Overtightening Freeze Plugs: Freeze plugs should be pressed into the cam bearing bores finger-tight. Overtightening can damage the freeze plug or the cam bearings.
• Using Incorrect Bearing Clearance: As mentioned earlier, bearing clearance is critical for proper camshaft operation. Too tight or too loose a clearance can lead to problems.
• Not Lubricating Bearing Surfaces: Failure to lubricate the cam bearings and camshaft before installation can result in excessive wear and friction.

Conclusion

Installing cam bearings on an SBC engine requires attention to detail and precision. By following these steps, using the right tools, and avoiding common mistakes, you can ensure that your camshaft operates smoothly and reliably for years to come.

Call to Action

If you are rebuilding or modifying an SBC engine, take the time to install the cam bearings correctly. Remember, a properly installed camshaft is crucial for engine performance and longevity.