How To Set Valves On Small Block Chevy

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

Setting the valves on your small block Chevy engine is a crucial maintenance task that ensures optimal engine performance and longevity. This process, also known as valve adjustment, involves precisely setting the clearance between the valve stem and the rocker arm. Incorrect valve adjustment can lead to decreased power, poor fuel economy, and even engine damage. This guide provides a step-by-step process to help you successfully set your valves.

Tools and Materials You'll Need

Before you begin, gather the necessary tools and materials. This will make the process smoother and more efficient. You'll need:

• Socket set: A comprehensive set with various sizes will be essential.
• Wrench set: Similar to the socket set, a variety of sizes is crucial.
• Valve adjustment tool (feeler gauges): These are crucial for accurately measuring valve clearance. Make sure you have the correct sizes for your engine specifications.
• Torque wrench: For tightening bolts and nuts to the manufacturer's specified torque. Using the wrong torque can damage engine components.
• Shop manual: A factory service manual specific to your small block Chevy engine year and model is highly recommended. This will provide crucial specifications and diagrams.
• Jack stands and jack: Essential for safely lifting and supporting your vehicle.
• Gloves and safety glasses: Protect yourself from potential hazards.
• Clean rags: For cleaning and wiping down parts.
• Pen and paper: For recording valve clearances before and after adjustment.

Step-by-Step Valve Adjustment Process

1. Preparation is Key

• Safety First: Always disconnect the negative battery terminal before starting any work on your vehicle's engine.
• Vehicle Preparation: Securely lift and support the vehicle using jack stands. Never work under a vehicle supported only by a jack.
• Access: Remove any components necessary to access the rocker arms and valve covers. Consult your shop manual for specific instructions related to your engine.

2. Locating the Valve Adjustment Points

• Identification: Familiarize yourself with the location of each valve and its corresponding rocker arm. Your shop manual will provide detailed diagrams.
• Understanding Valve Train: Understand the components of the valve train, including the camshaft lobe, pushrods, rocker arms, and valves.

3. Measuring Valve Clearance (Pre-Adjustment)

• Engine Position: With the engine at top dead center (TDC) on the compression stroke of the cylinder you are working on, you can begin to measure the valve clearance. Your shop manual will detail how to accurately find TDC for each cylinder.
• Using Feeler Gauges: Carefully insert the appropriate feeler gauge between the valve stem and the rocker arm. The correct clearance will be specified in your shop manual. It's usually expressed in thousandths of an inch.
• Recording Measurements: Record the initial valve clearances for both the intake and exhaust valves of each cylinder.

4. Adjusting Valve Clearance

• Adjusting Screws: Most small block Chevys use adjusting screws on the rocker arms. Turn these screws to increase or decrease the clearance, as needed. Use the feeler gauge to achieve the correct clearance.
• Lock Nuts: After achieving the correct clearance, tighten the lock nut securely. Use your torque wrench to achieve the manufacturer's specified torque. Incorrect torque can damage your valve train components.
• Re-Check: After tightening the lock nut, re-check the valve clearance to make sure it hasn't changed.

5. Reassembly and Testing

• Reassembly: Carefully reinstall all components that were removed to access the rocker arms. Ensure everything is properly secured and tightened to the correct torque specifications.
• Start the Engine: Once everything is reassembled, start the engine and listen for any unusual noises. If you hear ticking or tapping, re-check your valve adjustments.

Tips for Success

• Patience and Precision: Setting valves requires patience and attention to detail. Take your time and ensure accurate measurements.
• Refer to Your Manual: Your shop manual is your best friend throughout this process. Follow the instructions precisely.
• Cleanliness: Keep everything clean. Dirt and debris can interfere with valve operation.

By following these steps and consulting your shop manual, you can successfully set the valves on your small block Chevy engine, leading to improved performance and reliability. Remember, safety is paramount, so take the necessary precautions.