The Ultimate Guide to Installing Cam Bearings in an SBC Engine

Installing cam bearings in a small-block Chevrolet (SBC) engine is a critical step in rebuilding or modifying the engine. This comprehensive guide will provide step-by-step instructions, tips, and troubleshooting advice to ensure a successful installation.

Understanding Cam Bearings

Cam bearings are precisely machined metal sleeves that support the camshaft within the engine block. They reduce friction and prevent excessive wear on both the camshaft and the block. SBC engines typically use five cam bearings, located in the main bearing saddles of the block.

When installing cam bearings, it is critical to ensure the correct size and type of bearing is used for each location. The incorrect bearing can

• compromise engine performance and

• cause catastrophic failure.

Table 1: SBC Cam Bearing Sizes and Locations

Tools and Materials Required

Before starting the installation, gather the following tools and materials:

• Cam bearings
• Cam bearing installer
• Hammer or press
• Dial indicator and base
• Camshaft
• Engine block
• Engine oil

Step-by-Step Installation Procedure

1. Preparation

• Thoroughly clean the camshaft and bearing surfaces in the engine block.

  

• Apply a thin layer of engine oil to the camshaft and bearings.

2. Bearing Installation

• Insert the correct bearing into the bearing saddle, using the cam bearing installer.

• Gently tap the bearing into place with a hammer or press, ensuring it is fully seated.

3. Bearing Alignment

• Install the camshaft in the block, but do not tighten the retaining bolts yet.

• Use a dial indicator and base to check the runout (side-to-side movement) of the camshaft at each bearing.

• If the runout exceeds 0.002 inches, carefully adjust the bearings as needed to bring it within tolerance.

4. Tightening

• Once the bearings are aligned, tighten the camshaft retaining bolts to the manufacturer's specified torque.

5. Final Inspection

• Reinstall the camshaft and check the runout again.

• If the runout is still within tolerance, the cam bearings have been installed successfully.

Tips and Tricks

• Always use a cam bearing installer. This tool ensures the bearings are installed square and without damage.

• Do not overtighten the camshaft retaining bolts. This can cause the bearings to bind and damage the camshaft.

• If you do not have a dial indicator, you can use a feeler gauge to check the bearing alignment.

• Consider using cam bearing lube. This specialized lubricant provides additional protection** for the camshaft and bearings.

Troubleshooting

Problem: Excessive camshaft runout

Potential Causes:

• Incorrectly installed cam bearings
• Damaged cam bearings
• Warped engine block

Problem: Cam bearing seizure

Potential Causes:

• Overtightened camshaft retaining bolts
• Lack of lubrication
• Excessive bearing clearance

Stories and Lessons Learned

Story 1:

The Importance of Proper Bearing Alignment

Once, a mechanic installed cam bearings in an SBC engine and skipped the alignment step. When the engine was started, the camshaft seized due to excessive runout. The mechanic learned the hard way that bearing alignment is critical for a successful installation.

Story 2:

The Danger of Overtightening

Another mechanic tightened the camshaft retaining bolts too much, causing the cam bearings to bind. The camshaft failed prematurely, and the engine had to be rebuilt. The mechanic realized that following the manufacturer's torque specifications is essential.

Story 3:

The Benefits of Cam Bearing Lube

A mechanic used cam bearing lube on an SBC engine he was rebuilding. The engine ran smoothly and quietly for years, with minimal camshaft wear. The mechanic attributed this success to the protective benefits of the cam bearing lube.

Effective Strategies

• Plan the installation carefully and gather all necessary tools and materials before starting.

• Follow the step-by-step procedure outlined in this guide meticulously.

• Check bearing alignment with a dial indicator or feeler gauge.

• Tighten camshaft retaining bolts to the manufacturer's specified torque.

• Consider using cam bearing lube for additional protection.

Pros and Cons

Pros:

• Improved engine performance
• Reduced camshaft wear
• Prevents bearing seizure

Cons:

• Can be time-consuming
• Requires specialized tools
• Can be challenging to align bearings correctly

Conclusion

Installing cam bearings in an SBC engine is a critical step that requires precision and attention to detail. By following the steps outlined in this guide, using the appropriate tools, and taking the necessary precautions, you can ensure a successful installation that will enhance engine performance and extend its lifespan.