Chevy 350 Valve Adjustment: A Step-by-Step Guide
The small-block Chevy 350, a legendary engine known for its power and reliability, requires regular maintenance to keep it running smoothly. One crucial aspect of this maintenance is valve adjustment. Improperly adjusted valves can lead to decreased performance, reduced fuel efficiency, and even engine damage. This comprehensive guide will walk you through the process of adjusting valves on your Chevy 350, ensuring your engine continues to perform at its best. This guide is for informational purposes only and should not be considered a substitute for professional mechanic guidance. Always consult your vehicle's service manual for specific recommendations and safety precautions.
Tools and Materials You'll Need
Before you begin, gather the necessary tools and materials. This will make the process much smoother and safer. You'll need:
- Valve adjustment wrench set: This typically includes feeler gauges of various thicknesses and a wrench specifically designed for adjusting rocker arm nuts. Ensure you have the correct size for your engine.
- Feeler gauges: These are crucial for measuring the valve clearance. A set covering the range of specifications for your Chevy 350 is essential.
- Socket wrench set: You might need various sockets for removing components.
- Wrench set: For various nuts and bolts.
- Torque wrench: Essential for tightening bolts to the manufacturer's specified torque.
- Mechanic's gloves: To protect your hands.
- Shop towels: To keep your workspace clean.
- Owners manual: To reference the correct specifications for your specific engine.
- Jack stands: Essential for safety when working under the vehicle.
- Appropriate jack: To lift the vehicle safely.
Preparing Your Chevy 350 for Valve Adjustment
Safety First: Remember to always disconnect the negative battery terminal before starting any work on your vehicle's electrical system.
- Warm-up the Engine: Run the engine until it reaches normal operating temperature. This allows for accurate valve clearance measurement.
- Secure the Vehicle: Safely raise the vehicle using a jack and secure it with jack stands. Never work under a vehicle supported only by a jack.
- Access the Valve Cover: Remove the valve cover(s). This will expose the rocker arms and pushrods, allowing access to the valves.
The Valve Adjustment Process: A Step-by-Step Guide
The process involves checking and adjusting the clearance between the valve stem and the rocker arm. The exact specifications for your Chevy 350 engine can be found in your owner's manual; however, typical clearances range between 0.016" and 0.020" for intake valves and 0.020" to 0.024" for exhaust valves. Always refer to your owner's manual for precise values.
- Identify the Valves: Familiarize yourself with the intake and exhaust valves on your engine. There are several methods to distinguish them – from visual inspection to reference guides.
- Rotate the Engine: Carefully rotate the engine using the crankshaft pulley bolt. This allows you to reach each valve individually in the proper sequence. You'll need to adjust the valves one at a time while ensuring the rocker arm is fully relaxed to provide accurate measurements.
- Check Valve Clearance: Insert the appropriate feeler gauge between the valve stem and the rocker arm. If the gauge slides easily, the clearance is too large. If it's too tight, the clearance is too small.
- Adjust Valve Clearance: Use the valve adjustment wrench to tighten or loosen the rocker arm nut until the feeler gauge provides the correct resistance. Once the correct clearance is achieved, tighten the nut securely, but avoid over-tightening. Consult your owner's manual for the proper torque specification.
- Repeat for Each Valve: Repeat steps 2-4 for each intake and exhaust valve in your engine. Accurate and methodical adjustment is crucial for proper engine operation.
Frequently Asked Questions (FAQs)
How often should I adjust my Chevy 350 valves?
The frequency of valve adjustments depends on factors like engine wear and driving habits. Generally, it's recommended to check and adjust valves every 30,000 – 50,000 miles or as recommended in your owner's manual.
What happens if my valves are not adjusted correctly?
Incorrect valve adjustment can lead to decreased engine performance, poor fuel economy, burnt valves, and potentially severe engine damage.
Can I adjust my valves myself, or should I take it to a mechanic?
While valve adjustment is a manageable task for mechanically inclined individuals, it requires precision and knowledge. If you're not comfortable with engine work, it's best to have a qualified mechanic perform the adjustment.
What are the signs of needing a valve adjustment?
Signs can include rough running, loss of power, noisy valve train, and decreased fuel economy.
What type of feeler gauges should I use for a Chevy 350?
Use a set of feeler gauges that includes the thicknesses specified in your engine's service manual. These gauges are typically measured in thousandths of an inch.
Conclusion
Regular valve adjustment is crucial for maintaining the performance and longevity of your Chevy 350 engine. By following this step-by-step guide, you can ensure your engine runs smoothly and efficiently for years to come. Remember, safety is paramount; always prioritize careful and methodical work when performing maintenance on your vehicle. If you are unsure about any step, consult a qualified mechanic.
