Discover the Secret to Checking Cylinder Head Straightness: A Step-by-Step Guide

A warped cylinder head is a common problem that can lead to a variety of engine issues, including decreased performance, increased fuel consumption, and even engine failure. Knowing how to check cylinder head for straightness is a crucial skill for any DIY mechanic or car enthusiast. This guide will walk you through the process, equipping you with the knowledge to diagnose and potentially fix this common engine problem.

The Importance of a Straight Cylinder Head

The cylinder head is a critical component of your engine, responsible for sealing the combustion chamber and providing a smooth surface for the piston to travel within. If the cylinder head is warped, it can cause a number of problems, including:

• Compression loss: A warped cylinder head can create gaps between the head and the block, allowing combustion pressure to escape. This can lead to a loss of power and efficiency.
• Head gasket leaks: A warped cylinder head can cause the head gasket to fail, allowing coolant to leak into the combustion chamber or oil to leak into the coolant.
• Premature wear: A warped cylinder head can cause the valves to wear out prematurely, as they are forced to operate against an uneven surface.

Tools You’ll Need

Before embarking on the journey to check your cylinder head for straightness, gather the following tools:

• Straight edge: A long, flat, and rigid ruler or metal bar.
• Feeler gauge: A tool used to measure gaps, typically used for checking valve clearances but also useful for measuring the gap between the cylinder head and the surface plate.
• Surface plate: A flat and smooth surface used as a reference point for checking the straightness of the cylinder head. A granite surface plate is ideal, but a large, flat piece of glass or a sturdy table can be used as a substitute.
• Measuring tape: For accurately measuring the length of the straight edge and the surface plate.
• Cleaning supplies: To ensure a clean and accurate measurement, you’ll need a cleaning cloth and a suitable cleaning agent to remove any dirt or debris from the cylinder head and the surface plate.

Preparation: Setting the Stage

1. Remove the cylinder head: This step requires basic engine repair knowledge and tools. Consult your vehicle’s repair manual for detailed instructions.
2. Clean the cylinder head: Thoroughly clean the mating surface of the cylinder head with a suitable cleaning agent and a soft cloth. Remove any dirt, oil, or debris that could affect the accuracy of your measurements.
3. Prepare the surface plate: Ensure your surface plate is clean and free of debris.

The Straight Edge Test: Unveiling Warpage

1. Position the straight edge: Place the straight edge across the cylinder head mating surface, ensuring it is parallel to the surface.
2. Check for gaps: Use a feeler gauge to check for any gaps between the straight edge and the cylinder head. If you find gaps, this indicates a warped cylinder head.
3. Measure the gap: Measure the gap at different points along the straight edge. This will help you determine the severity of the warp.

Interpreting the Results: What the Gaps Mean

• Minimal gaps: A gap of less than 0.005 inches is usually considered acceptable.
• Moderate gaps: Gaps between 0.005 and 0.010 inches may indicate a slight warp.
• Significant gaps: Gaps greater than 0.010 inches are a clear sign of a warped cylinder head and require immediate attention.

Alternative: The Dial Indicator Method

For a more precise measurement, you can utilize a dial indicator. This method provides a numerical reading of the warp, offering greater accuracy than the straight edge method.

1. Mount the dial indicator: Securely mount the dial indicator to a sturdy stand.
2. Position the indicator: Place the dial indicator‘s probe directly on the cylinder head mating surface.
3. Zero the dial: Zero the dial indicator when the probe is resting on the surface plate.
4. Traverse the head: Move the dial indicator probe across the cylinder head mating surface, noting any deviations from zero.
5. Interpret the readings: Any readings that deviate from zero indicate a warp. The larger the deviation, the more severe the warp.

Remedies for a Warped Cylinder Head

If your cylinder head is warped, you have several options:

1. Resurface: A machine shop can resurface the cylinder head to remove the warp. This process involves grinding down the mating surface to create a flat and smooth surface.
2. Replacement: If the warp is severe or the cylinder head has other damage, it may be necessary to replace it with a new one.

Final Thoughts: Maintaining Engine Health

Regularly checking your cylinder head for straightness is crucial for maintaining the health of your engine. By catching a warped cylinder head early, you can prevent further damage and ensure your engine runs smoothly and efficiently.

Questions We Hear a Lot

Q: Can I drive my car if the cylinder head is slightly warped?

A: It’s not recommended. Even a slight warp can lead to performance issues and damage to other engine components. It’s best to address the problem promptly.

Q: How often should I check my cylinder head for straightness?

A: There’s no strict schedule, but it’s a good practice to check it during major engine repairs or if you notice any signs of engine problems like loss of power, coolant leaks, or unusual noises.

Q: Can I use a flat piece of metal instead of a surface plate?

A: While a flat piece of metal can be used as a substitute, a dedicated surface plate is more accurate and ensures a reliable measurement.

Q: Is it possible to fix a warped cylinder head myself?

A: It’s not recommended. Resurfacing a cylinder head requires specialized equipment and expertise. It’s best to have this work done by a qualified mechanic or machine shop.