Installing Cam Bearings in a Small Block Chevy: A Comprehensive Guide

Installing cam bearings in a small block Chevy (SBC) is a critical step in rebuilding a performance engine. Accurate alignment and proper installation are crucial to ensure that the camshaft operates smoothly and without excessive wear. This guide provides a comprehensive step-by-step approach to ensure successful cam bearing installation.

1. Materials and Tools

Gather the following materials and tools:

• New cam bearings (Standard or Oversized)
• Cam bearing installer tool
• Dial indicator
• Dial indicator base
• Micrometer
• Bearing hone
• Engine block
• Cam bearing lubricant

2. Preparation

• Clean the engine block thoroughly to remove any debris.
• Inspect the cam bearing bores for wear or damage.
• Hone the cam bearing bores to a tolerance of 0.0005-0.0015 inches (Refer to the manufacturer's specifications for specific tolerances).

3. Cam Bearing Selection

• Standard bearings: Suitable for most stock or mildly modified engines.
• Oversized bearings: Used to compensate for wear or misalignment in the cam bearing bores.

4. Cam Bearing Installation

• Lubricate the cam bearings with the recommended bearing lubricant.
• Use the cam bearing installer tool to press the bearings into the engine block. Ensure the bearings are fully seated and flush with the block surface.
• Verify the bearing alignment using a dial indicator set on a dial indicator base. Adjust the bearing position as necessary to achieve 0.002-0.003 inches of end float.

5. Cam Measurement

• Measure the camshaft journal diameter using a micrometer.
• Calculate the cam bearing clearance by subtracting the journal diameter from the cam bearing bore diameter.
• Typical clearance: 0.001-0.002 inches for stock to mild performance engines, and 0.002-0.003 inches for high-performance engines.

6. Bearing Hone

• Use a bearing hone to lightly hone the cam bearing bores in the direction of camshaft rotation.
• Remove any burrs or high spots created during installation.

7. Inspection

• Visually inspect the cam bearings for any damage or misalignment.
• Reinstall the camshaft and check for any binding or excessive play.

8. Benefits

• Reduced friction and wear: Properly installed cam bearings minimize friction between the camshaft and engine block, extending engine life.
• Improved oil flow: Cam bearings help distribute oil to the camshaft journals, ensuring proper lubrication and cooling.
• Precision timing: Accurate bearing alignment ensures precise camshaft timing, maximizing engine performance.

9. Potential Drawbacks

• Improper installation: Incorrect bearing installation can lead to misalignment, excessive clearance, and premature wear.
• Material selection: Choosing the wrong bearing material can result in reduced durability or premature failure.
• Expense: Installing cam bearings can be a costly process, especially if oversized bearings or additional machining is required.

10. Stories

• The Tale of the Oversized Bearings: A mechanic installed oversized cam bearings in an SBC to compensate for worn cam bearing bores. However, he failed to hone the bores properly, resulting in excessive clearance and a noisy engine. The lesson: always follow proper installation procedures.
• The Case of the Loose Cam: A DIY enthusiast installed cam bearings without measuring the cam bearing clearance. The result was a loose camshaft that rattled and caused engine damage. The lesson: precision is key when installing cam bearings.
• The Miracle Bearing: A seasoned mechanic was tasked with rebuilding an SBC with a damaged camshaft. After replacing the camshaft, he discovered that the cam bearing bores were out of spec. Using an innovative technique, he honed the bores to the correct tolerance and installed cam bearings without replacing the engine block. The lesson: creativity and ingenuity can overcome challenges.

11. Conclusion

Installing cam bearings in a small block Chevy is a critical step in engine rebuilding. By following the steps outlined in this guide, you can ensure accurate alignment, proper clearance, and long-lasting engine performance. Remember, precision and attention to detail are essential for a successful cam bearing installation.

Additional Resources

• Small Block Chevy Cam Bearing Installation Guide
• SBC Cam Bearing Size Chart

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