Overview
- Place the cylinder head on a surface plate and use a machinist ruler to check for warpage.
- Apply a thin layer of head gasket sealant to both the cylinder head and block surfaces according to the manufacturer’s instructions.
- Use a torque wrench to tighten the cylinder head bolts in a specific sequence and to the specified torque.
Skimming cylinder heads is a crucial step in engine rebuilding or maintenance. It involves removing a precise amount of material from the head’s surface to ensure a proper seal and optimal engine performance. While it may seem intimidating, skimming cylinder heads at home is possible with the right tools, knowledge, and patience. This comprehensive guide will walk you through the entire process, empowering you to tackle this task with confidence.
Safety First
Before embarking on any automotive project, it’s paramount to prioritize safety. Wear appropriate protective gear, including gloves, eye protection, and a dust mask. Ensure your workspace is well-ventilated and free from flammable materials.
Tools and Materials
To successfully skim cylinder heads at home, you’ll need the following tools and materials:
- Cylinder head gasket
- Cylinder head bolts
- Head gasket sealant
- Surface plate
- Machinist ruler
- Feeler gauge
- Emery cloth or sandpaper
- Cutting fluid
- Torque wrench
- Dial indicator (optional)
Preparation
1. Remove the Cylinder Head: Carefully disassemble the engine and remove the cylinder head. Clean the head thoroughly to remove any debris or gasket residue.
2. Check for Warpage: Place the cylinder head on a surface plate and use a machinist ruler to check for warpage. If the head is warped by more than 0.002 inches, it will need to be resurfaced by a professional machine shop.
Skimming the Cylinder Head
1. Mark the Cutting Surface: Use a felt-tip pen or marking fluid to outline the raised areas on the cylinder head‘s surface. These areas indicate where material needs to be removed.
2. Sanding and Grinding: Gradually remove material from the marked areas using emery cloth or sandpaper. Use a light touch and apply cutting fluid to prevent overheating.
3. Check for Flatness: Regularly measure the head’s surface with a machinist ruler or feeler gauge to ensure it’s becoming flat. Aim for a tolerance of 0.001 inches or less.
4. Use a Dial Indicator (Optional): For greater precision, mount a dial indicator on a magnetic base and measure the head’s surface. This allows you to monitor progress and achieve a perfectly flat surface.
Reassembly
1. Clean the Surfaces: Thoroughly clean the cylinder head and block mating surfaces to remove any debris.
2. Apply Head Gasket Sealant: Apply a thin layer of head gasket sealant to both the cylinder head and block surfaces according to the manufacturer’s instructions.
3. Install the Head Gasket: Carefully position the cylinder head gasket over the block, ensuring it’s properly aligned.
4. Tighten the Cylinder Head Bolts: Use a torque wrench to tighten the cylinder head bolts in a specific sequence and to the specified torque.
5. Check for Leaks: Once the head is installed, run the engine and check for any leaks. If leaks are present, retighten the bolts or replace the gasket.
Finishing Touches
1. Break-In: Follow the manufacturer’s recommended break-in procedure for your engine. This typically involves driving the vehicle gently for a period to allow the head gasket to fully seal.
2. Maintenance: Regularly inspect the cylinder head for any signs of wear or damage. If necessary, have it resurfaced by a professional to ensure continued optimal performance.
Final Thoughts
Skimming cylinder heads at home requires patience, precision, and a commitment to safety. By following the steps outlined in this guide, you can confidently tackle this task and achieve a perfectly flat cylinder head surface. Remember to prioritize safety, use the right tools, and don’t hesitate to seek professional assistance if needed. With the knowledge and skills you gain from this guide, you’ll be well-equipped to maintain and repair your engine with confidence.
Frequently Asked Questions
Q: How often should I skim my cylinder head?
A: Skimming a cylinder head is not a routine maintenance task. It should only be done when necessary, such as after major engine repairs or if the head is warped or damaged.
Q: Can I use a power sander to skim my cylinder head?
A: While it’s possible to use a power sander, it’s not recommended for beginners. Manual sanding with emery cloth or sandpaper provides greater control and precision.
Q: What are the signs of a warped cylinder head?
A: Symptoms of a warped cylinder head can include overheating, coolant leaks, and reduced engine performance. Checking the head’s flatness with a surface plate or machinist ruler can confirm warpage.
Q: How much material should I remove when skimming the cylinder head?
A: The amount of material to remove depends on the specific head and engine. Always refer to the manufacturer’s specifications or consult with a professional machinist.
Q: Can I skim a cylinder head without removing it from the engine?
A: It’s not recommended to skim a cylinder head while it’s still installed on the engine. Removing the head allows for proper cleaning, inspection, and precision sanding.