- Cylinder Head Crack Detection
- Cylinder Head Check For Cracks Back
- Cylinder Head Check For Cracks In House
- Cylinder Head Crack Repair
The cylinder head reaches the highest temperature of any engine component, often thousands of degrees. Water jackets need to be incorporated into cylinder heads to cool them down so they don't completely distort and burn out the head gaskets. The cast iron and aluminum metals used in cylinder heads continually flex under the high temperatures and pressures, and are allowed to do so within limitations. Sometimes, however, the heat can become so excessive that the heads bulge and warp beyond these limits. When this happens it is necessary to dissemble the engine and measure the specified tolerances.
Step 1
Refer to your owner's repair manual for the correct procedure to remove the head (or heads) from your vehicle. Use the require tools, and have an assistant help you with the chore of lifting and transporting the head to a flat, clean bench surface. Have a technical repair manual to refer to.
For more about cylinder head cracks, read Cylinder Head Failure Analysis: Why is My Head Cracked? Poor Inspection. The tooling required to properly inspect a cylinder head and associated parts is getting more advanced. Not that long ago, the first life of an engine was in the 500,000 - 750,000 mile range. So the most common cylinder head repairs we see on new cars are from overheating or leaking head gaskets. On these heads we will check them for straightness first, then check them for cracks, and then resurface them if possible. With a broken timing belt we will have to disassemble the head, clean and check all of the valves and valve guides. Cylinder Head Pressure Test: Another critical area of cracked cylinder head repair. There are various methods of pressure testing. We feel that sealing the cylinder head, pressurizing it and submerging it under water is the best method.
A cracked cylinder head can mean an expensive repair bill for your vehicle. There are several ways to tell if your problem is a cracked cylinder head. Leaking Coolant. With a badly cracked cylinder head, your coolant can leak from the cylinder head, and your engine will be running hot. The best way to preserve the life of your cylinder heads is to keep your radiator filled and make sure you have no stretches hoses or leaky belts. If your car ever overheats then have your head gaskets replaced and the heads checked or cracks. Best Answer: It is not possible to tell which has occurred in most cases, but cracks in aluminum heads (like most modern cars, your Chevy has aluminum heads) are fairly rare. The cast iron heads used 40 years ago were brittle and prone to cracking, and the worry has carried over. Head gasket failure from overheating aluminum heads on a cast iron block - the standard for engines these days - is. The Newclear Pressure Tester is a revolutionary new machine that has been specifically designed for the automotive engineering industry. It has the capability to effectively test various cylinder heads and blocks e.g. A single Honda cylinder head, a Cummins 350 big cam block or a cummins NH block.
Step 2
Use a wire brush and carburetor cleaner to completely clean the bottom, sides and top of the head. There should be no carbon in the cylinder head combustion chambers or on the flat part of the mating surface. When you have finished you should have a shiny metal surface.
Step 3
Place the head with the combustion chamber facing up. Secure it in a wide-jaw vice, or prop the head with wood blocks to keep it stable. Take a new, steel straight edge ruler and place it along the outside edge, from one end of the head to the other. Place a feeler gauge in the gap between the bottom of the ruler and the head surface. Start off with the smallest feeler gauge blade.
Step 4
Work the feeler gauge along the head until the feeler gauge slides in. Change the blade thickness of the feeler gauge to find the maximum allowable gauge thickness that will enter the gap. Measure up and down the length of the head and record the thickest feeler gauge blade that passed through the gap. Write that number down. Perform the exact same procedure on the other side of the head. Write down the thickest blade measurement that passed under the straight edge.
Step 5
Place the straight edge along the cross-section of the head, from one corner to the opposite corner. You will do the same with the other corner, which will form an 'X' pattern across the head, bisecting it through the middle. Record the thickest blade that passes through one angle. Write the number down. Switch to the other corners and take the same measurement. Write down the thickest blade that passed under the straight edge.
Step 6
Cylinder Head Crack Detection
Measure straight across the ends of the cylinder head and record the thickest feeler gauge blade that will pass under the gap. Perform the same measurement on the other side. You should have six measurements. Refer to your tech repair manual for the maximum allowable 'out-of-flat' tolerances, which will be measured in thousandths of an inch. Aluminum head tolerances will not be the same as cast iron, so make sure you have the correct type head numbers, as well as the engine configuration.
Compare your numbers to the highest allowable for your engine. For instance, a V-6 engine should not have a higher number than 0.003 inches. Any number exceeding 0.004 inches for a four-cylinder or V-8 head will be beyond specifications. Straight six cylinder heads can have no more than 0.006 inches.
Items you will need
- Tech repair manual
- Owner's repair manual
- Bench vice (if applicable)
- Wood blocks
- Carburetor cleaner
- Wire brush
- Steel straight edge ruler (24-inch)
- Feeler gauges
- Pad and pencil
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Cylinder Head Check For Cracks In House
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Cylinder Head Crack Repair
The cylinder head is a crucial part of all combustion engines, and cylinder head cracking can result in catastrophic damage to the engine. In some cases, cracking may result in such severe injury to the engine that it must be replaced. As a result, most motorists try to prevent cylinder head cracking, as an ounce of prevention in this case is worth many pounds of cure. The causes of cracking are all relatively simple and easy to prevent, except in the case of mechanical parts failure through no fault of the operator.
The cylinder head, used in combination with a head gasket, seals the cylinders of the car, along with other parts associated with them. The cylinder head is customized for the vehicle, and has very precisely milled surfaces to provide a smooth and flush fit with all connecting parts. In the case of a minor crack, the cylinders may lose compression and misfire. Major cracks can cause severe damage to the cylinders of the engine. For this reason, when replacing either the cylinder head or the head gasket, make sure that you are using the correct parts, including bolts, for the job.