How To Set Valves On A Chevy 350

How to Set Valves on a Chevy 350 Small Block: A Comprehensive Guide

Setting the valves on your Chevy 350 small block engine is a crucial maintenance task that ensures optimal engine performance and longevity. This process, while seemingly complex, can be tackled with the right tools, knowledge, and patience. This guide will walk you through the steps, providing a clear understanding of each stage.

Tools You'll Need

Before you begin, gather the necessary tools. Having everything ready will streamline the process and prevent delays. You'll need:

• Valve spring compressor: This is essential for safely compressing the valve springs.
• Socket set: A variety of sizes will be needed for removing and installing components.
• Torque wrench: Crucial for tightening bolts to the manufacturer's specifications. This prevents damage to the engine.
• Feeler gauges: These precisely measure the valve lash (clearance).
• Pry bar or similar tool: Helpful for manipulating components and removing stubborn parts.
• Shop rags or clean towels: Keep your workspace clean and free of debris.
• Owners manual or repair manual: Consult this for torque specifications and other vital information specific to your engine.
• Pencil and paper: To jot down measurements and settings.

Preparation: The Foundation for Success

• Safety First: Disconnect the negative battery terminal before beginning any work on your vehicle. This prevents accidental electrical shorts.
• Engine Access: Ensure you have adequate access to the valve train. This might require removing parts like the valve covers.
• Cleanliness: Clean the valve cover and surrounding areas to prevent dirt from contaminating the engine.

Step-by-Step Valve Adjustment

The following steps will guide you through the process of adjusting your Chevy 350's valves. Remember to always consult your engine's specific specifications for accurate measurements.

1. Finding Top Dead Center (TDC)

• Identify the Number 1 Cylinder: Locate the number 1 cylinder (usually marked on the engine).
• Rotate the Crankshaft: Slowly rotate the crankshaft using a wrench on the crankshaft pulley until the piston in the number 1 cylinder is at top dead center (TDC) on the compression stroke. This is where both intake and exhaust valves are closed. You can verify this by visually inspecting the timing marks on the crankshaft and camshaft. Accurate TDC is critical for correct valve adjustment.

2. Compressing the Valve Springs

• Secure the Compressor: Carefully attach the valve spring compressor to the valve spring. Ensure it's securely fastened to prevent accidental release.
• Compress and Remove Keepers: Compress the spring until you can remove the valve keepers. These are small clips holding the valve in place. You'll need to use a magnetic retrieval tool or a pair of needle-nose pliers to remove and later replace the keepers.

3. Measuring and Adjusting Valve Lash (Clearance)

• Feeler Gauge Check: Once the spring is compressed and the keepers are removed, carefully insert the appropriate feeler gauge between the valve stem and the rocker arm. The feeler gauge should slide smoothly with slight resistance. This determines the proper valve lash. Your owner's manual will specify the exact measurements for your engine (usually expressed in thousandths of an inch).
• Adjust the Rocker Arm: If the clearance isn't correct, adjust the rocker arm using the adjusting nut or screw until the feeler gauge slides with the correct amount of resistance. Remember to tighten the nut securely to prevent movement.

4. Reassembly and Repeat

• Reinstall Keepers: Once the valve lash is set correctly, carefully reinstall the valve keepers using a magnetic retrieval tool or needle-nose pliers.
• Release the Compressor: Slowly release the valve spring compressor.
• Repeat for all Valves: Repeat this process for all intake and exhaust valves, ensuring that you always return the crankshaft to the correct TDC for each cylinder before adjusting. The firing order for your Chevy 350 will guide you through the proper sequence.

5. Double Check and Torque Specs

• Double Check Valve Lash: After adjusting all the valves, double check the lash of each valve to ensure accuracy.
• Torque Specs: Use your torque wrench to ensure that all rocker arm bolts are tightened to the specified torque value found in your engine's manual. Incorrect torque can damage the engine.

Post-Adjustment Checks and Considerations

• Restart and Listen: After completing the valve adjustment, start the engine and listen carefully for any unusual noises. Unusual noises can indicate an issue with the adjustment process.
• Regular Maintenance: Regular valve adjustments are part of routine engine maintenance. Consult your owner's manual for recommended intervals.

This guide provides a general overview. Always refer to a reputable repair manual specific to your Chevy 350 engine model for precise specifications and detailed instructions. Improper valve adjustment can lead to engine damage. If you are not comfortable performing this task, consult a professional mechanic.