Get Better Gas Mileage: Adjust Your Chevy 350 Valves Now
The trusty Chevy 350 small-block engine—a legend in its own time. Known for its power and reliability, this engine can still deliver impressive performance, even after years of service. But if you’re noticing a drop in gas mileage, it might be time to consider a often-overlooked maintenance task: valve adjustment. Properly adjusted valves can significantly improve fuel efficiency and overall engine performance. This comprehensive guide will walk you through the process of adjusting your Chevy 350 valves and explain how it can help you achieve better gas mileage.
Why Valve Adjustment Impacts Gas Mileage
Before diving into the how-to, let's understand why valve adjustment is so crucial for fuel economy. Your Chevy 350's valves control the flow of air and fuel into the combustion chamber and the exhaust gases out. If the valves aren't properly adjusted, several issues can arise, directly impacting fuel efficiency:
- Incomplete combustion: Incorrect valve clearances can lead to incomplete combustion of the air-fuel mixture. This means wasted fuel and reduced power.
- Reduced compression: Loose valves can cause a loss of compression, further hindering efficient combustion and leading to poorer gas mileage.
- Increased wear and tear: Improper valve adjustment accelerates wear and tear on the valve train components, potentially leading to more significant and costly repairs down the line.
How Often Should I Adjust My Chevy 350 Valves?
The recommended interval for valve adjustment on a Chevy 350 varies depending on several factors, including the engine's age, usage, and the type of camshaft. However, a general guideline is to check and adjust your valves every 30,000 to 50,000 miles. Some enthusiasts prefer to do it more frequently, especially after a camshaft upgrade. Ignoring valve adjustment for extended periods can lead to decreased performance and fuel economy, so regular checks are crucial.
What Tools Do I Need to Adjust My Chevy 350 Valves?
Gathering the necessary tools beforehand is crucial for a smooth and efficient valve adjustment process. You'll need:
- Valve adjustment tool: A feeler gauge set with various thicknesses is essential for accurately measuring valve clearance.
- Socket set and wrenches: Appropriate size sockets and wrenches to remove and reinstall components.
- Torque wrench: To ensure proper tightening of the rocker arm nuts to prevent damage.
- Jack and jack stands: To safely lift the vehicle.
- Wheel chocks: To secure the vehicle during the process.
- Shop manual: A detailed Chevy 350 shop manual specific to your engine year and model is highly recommended. This will provide exact specifications and torque values.
- Safety glasses and gloves: Protecting yourself is paramount.
How to Adjust Chevy 350 Valves: A Step-by-Step Guide
This section provides a general overview. Always consult your vehicle's repair manual for precise instructions and specifications. This process varies slightly depending on the engine's year and modifications.
- Prepare the engine: Disconnect the negative battery terminal and safely lift the vehicle using a jack and jack stands.
- Remove the valve covers: Access the valve train by removing the valve covers.
- Rotate the engine: Rotate the crankshaft using a wrench on the harmonic balancer to position each cylinder at Top Dead Center (TDC) on the compression stroke.
- Measure valve clearance: Using the feeler gauge, measure the clearance between the rocker arm and the valve stem for each valve. Your shop manual will provide the correct specifications.
- Adjust valve clearance: Adjust the clearance by tightening or loosening the rocker arm adjusting nuts.
- Torque rocker arm nuts: Once the correct clearance is achieved, tighten the rocker arm nuts to the manufacturer's specified torque.
- Repeat for all valves: Repeat steps 4-6 for all intake and exhaust valves on each cylinder.
- Reassemble: Replace the valve covers and reconnect the battery.
- Test drive: After the adjustment, test drive the vehicle to assess the improvement in gas mileage and engine performance.
What if I Don't Adjust My Valves?
Neglecting valve adjustments can lead to several problems:
- Decreased fuel economy: As mentioned earlier, inefficient combustion directly translates to lower gas mileage.
- Reduced engine power: Poor valve adjustment can significantly reduce engine power and responsiveness.
- Premature engine wear: Incorrect valve clearances increase wear and tear on the entire valve train, potentially leading to costly repairs down the line.
- Engine damage: In extreme cases, severely misadjusted valves can lead to engine damage.
Can I Adjust Valves Myself?
While adjusting valves is a manageable DIY project for mechanically inclined individuals, it requires patience, precision, and the right tools. If you lack experience, it's best to consult a qualified mechanic. Improper adjustment can cause more harm than good.
How Much Can I Improve My Gas Mileage by Adjusting Valves?
The improvement in gas mileage will vary depending on the extent of the misadjustment. However, restoring proper valve clearance can often result in a noticeable improvement in fuel economy, sometimes up to a few miles per gallon. This improvement, coupled with other maintenance tasks, can contribute significantly to better fuel efficiency.
This article is intended for informational purposes only. Always consult a qualified mechanic or refer to your vehicle's repair manual for detailed instructions and safety precautions. Remember, safety should always be your top priority when working on your vehicle.
