How To Adjust Dwell On Points

If you're a classic car enthusiast or someone working on vintage ignition systems, understanding how to properly adjust the dwell on points is essential for optimal engine performance. Proper dwell adjustment ensures that the ignition points open and close at the correct times, providing a strong spark for efficient combustion. In this comprehensive guide, we'll walk you through the process of adjusting dwell on points, explain why it's important, and share tips to help you get the best performance from your engine.

What Is Dwell on Points?

Dwell refers to the amount of time, measured in degrees of distributor rotation, that the ignition points stay closed during each cycle. It directly influences the duration of the primary current flow through the ignition coil. Proper dwell ensures the coil is charged sufficiently before the points open, creating a strong spark for the spark plugs.

If the dwell angle is too small, the coil may not charge enough, resulting in weak sparks and poor engine performance. Conversely, if dwell is too large, the points may remain closed longer than intended, leading to excessive current flow, overheating, and premature points wear. Therefore, setting the correct dwell angle is crucial for reliable engine operation and longevity of your ignition system.

Tools Needed to Adjust Dwell

• Voltage or dwell meter (preferably a digital dwell meter)
• Basic hand tools (screwdrivers, wrenches)
• Service manual for your specific vehicle or ignition system
• Clean cloth or rag for cleaning points
• Light lubricant or contact cleaner (optional, for cleaning points)

Understanding Your Distributor and Points System

Before adjusting the dwell, it's important to understand your distributor setup. Most classic cars use mechanical points that open and close to switch the coil circuit on and off. The distributor cam, driven by the engine, opens and closes these points as it rotates.

The points' gap and the distributor's cam profile influence the dwell angle. Proper adjustment involves setting the correct points gap first, then fine-tuning the dwell for optimal performance.

Steps to Adjust Dwell On Points

1. Prepare Your Vehicle and Tools

Ensure your vehicle is parked on a level surface, the engine is cool, and the ignition is turned off. Gather all necessary tools, including the dwell meter, and consult your vehicle’s service manual for specific specifications related to dwell and points gap.

2. Access the Distributor

Remove any components blocking access to the distributor cap and points. Carefully disconnect the ignition coil wire and remove the distributor cap to expose the points and cam. Keep track of all parts for reassembly.

3. Clean and Inspect the Points

Using a clean cloth or a small brush, remove any dirt or corrosion from the points and contacts. If necessary, use contact cleaner or a light lubricant designed for electrical contacts. Inspect the points for pitting or excessive wear; replace if damaged.

4. Set the Points Gap

Using a feeler gauge, measure the points gap at the point of contact. Adjust the gap to the manufacturer’s specified setting, typically around 0.015 inches (0.38 mm). Loosen the screw holding the points and adjust the gap by gently bending the contact arm. Tighten the screw securely once correct.

5. Connect the Dwell Meter

Attach the dwell meter leads to the ignition coil terminal and ground (or follow the meter’s instructions). Ensure all connections are secure. Turn on the ignition, but do not start the engine yet.

6. Adjust the Dwell

Start the engine or manually turn the distributor cam using a screwdriver or a dedicated distributor wrench. Observe the dwell reading on the meter. The goal is to reach the manufacturer’s specified dwell angle, which is often between 30° and 40°, depending on the vehicle.

If the dwell is too low, slightly bend the points arm to increase the dwell. If it’s too high, decrease the dwell by adjusting the contact arm accordingly. Make small adjustments and recheck the reading after each change until the correct value is achieved.

7. Verify and Fine-Tune

Once the dwell is set correctly, turn off the engine and disconnect the dwell meter. Reassemble any components removed during the process. Start the engine and observe the spark quality and engine performance. If necessary, make minor adjustments to the points gap or dwell for optimal operation.

Additional Tips for Proper Dwell Adjustment

• Always refer to your vehicle’s service manual for specific dwell and points gap specifications.
• Replace worn or pitted points to maintain accurate dwell settings and prevent ignition issues.
• Regularly inspect and clean points as part of routine maintenance to ensure consistent performance.
• Be cautious not to over-bend the contact arm, as this can cause uneven wear or damage.
• Consider upgrading to electronic ignition systems for more stable and maintenance-free performance.

Common Problems When Dwell Is Not Properly Adjusted

Incorrect dwell settings can lead to various engine issues, including:

• Weak or inconsistent sparks, causing misfires
• Poor acceleration and sluggish performance
• Increased fuel consumption
• Engine hesitation or stalling
• Premature wear of points and ignition components

Addressing dwell issues promptly can prevent these problems and improve your vehicle's reliability and efficiency.

Benefits of Proper Dwell Adjustment

Maintaining the correct dwell angle offers numerous benefits, such as:

• Optimized engine performance and power output
• Better fuel efficiency
• Reduced wear and tear on ignition system components
• Smoother acceleration and idle
• Extended lifespan of points and distributor components

Conclusion

Adjusting the dwell on points may seem like a small task, but it plays a vital role in ensuring your engine runs smoothly and efficiently. Properly set dwell ensures the ignition coil charges correctly, providing strong sparks for combustion. While the process involves some patience and attention to detail, following the steps outlined above can help you achieve optimal ignition timing and prolong the life of your ignition system.

Whether you're restoring a vintage vehicle or maintaining a classic car, mastering how to adjust dwell on points is a valuable skill. Regular checks and adjustments can keep your engine running at peak performance, making your driving experience more enjoyable and reliable. Remember, proper maintenance is key to preserving the timeless charm and performance of your vintage ride.

Disclaimer: Articles are written by Humans, AI or Both. Verify Important information.