Why do engines have cylinder heads?

You can find all kinds of information about the head gasket, and many owners know its function, but much less about the cylinder head itself. That's why we've rounded up all the information you need to know about cylinder heads. Learn about how your car's cylinder head works, its importance, and the defects that can occur.

What does a cylinder head do?

The main task of the cylinder head is to close the combustion chamber of the engine from the top. The upper part of the engine is called the cylinder head and the lower part is called the engine block. The cylinder head is located on the engine and closes the combustion chamber. The clearance between the cylinder head and the engine is done by the cylinder gasket.

Another task of the cylinder head is to ensure the continuous lubrication of the cylinder. If the cylinders are not well oiled, the engine cannot run smoothly, which is why the cylinder head is an integral part of the engine's function.

How cylinder heads are made

Cylinder heads are not only a very important part of your engine, but they are also one of the most expensive parts of a vehicle's engine due to their complex construction. Since the cylinder head is exposed to very high temperatures during combustion, it is made of durable aluminum alloy and light metal.

At the bottom, it is usually fixed directly to the crankcase and closed at the top with a valve cover. Depending on whether your vehicle has a diesel or gasoline engine, the construction of the cylinder head varies.

These are the parts of a gasoline engine cylinder head

✴ Intake and exhaust ducts: these ensure that exhaust gases can escape from the cylinder and that the absorbed air-fuel mixture can enter the cylinder

✴ Intake and exhaust valves: these are where the gasoline engine draws in the air-fuel mixture while the exhaust gases are delivered to the exhaust system

✴ Camshaft: The crankshaft driven by the timing belt drives the camshaft. The camshaft is responsible for opening and closing the valves

✴ Injectors: they ensure that fuel is injected into the combustion chamber

✴ Spark plugs: they start the combustion of the fuel

These are the components of a diesel engine cylinder head

intake and exhaust ducts: they allow exhaust gases to escape from the cylinder and allow the captured air-fuel mixture to enter the cylinder

✴ Intake and exhaust valves: diesel vehicles draw air in through the intake and exhaust valves, while delivering exhaust gases to the exhaust system

✴ Camshaft: A crankshaft driven by a timing chain drives the camshaft. The camshaft is responsible for opening and closing the valves

✴ Injectors: These inject fuel from the diesel engine into the combustion chamber or front chamber

✴ Heat plugs: these act as cold start aids

How is the cylinder head cooled in the engine?

As mentioned above, cylinder heads are exposed to high temperatures and therefore must be cooled to avoid overheating and increased wear. There are two different types of cylinder head cooling: water-cooled or air-cooled.

Air-cooled cylinder heads

Air-cooled cylinder heads are cooled only by the air that passes through them. In addition, they are equipped with large heat sinks.

One of the advantages of this cooling method is that it ensures reliable functionality and can be built very easily and cheaply. Therefore, the repair of such cylinder heads is cheaper than the repair of water-cooled cylinder heads. In addition, you do not have to worry about the coolant freezing while cooling the air.

Water Cooled Cylinder Heads

Most modern engines are cooled by water. For this reason, a mixture of water and creamer is usually used as the coolant. To cool the cylinder head, the coolant enters the head through the cylinder head gasket.

One of the advantages of this cooling method is, first of all, that the coolant can absorb and dissipate a large amount of heat. In addition, this method of cooling is the most efficient.

Can cylinder heads have any defects?

Unfortunately, the complex structure of the cylinder head and its many tasks make it prone to defects. The most common defect is a leaking cylinder head gasket, which is caused by increased wear.

The cylinder head itself can also be defective, for example, due to the high temperatures and strong vibrations of a running engine. This can lead to cracks in the cylinder head material.

How to recognize the signs of a possible defect

If you notice that your engine is not running properly, it is recommended that you contact a repair shop as soon as possible to prevent further damage.

Signs of a defective cylinder head include.

✴ You notice a loss of engine power

✴The cooling water temperature is in the red zone

✴You see oil in the cooling water

✴You have to replenish water and oil in a short time

✴You notice a bad cold start behavior

Repair or fix a cylinder head?

Many defects may require repair of the cylinder head, which can be very expensive. Since the cylinder head is installed in the engine, a great deal of work on this engine component is associated with repair or restoration.

In most cases, the cylinder head must be removed after repair and then ground down, as this is the only way to ensure that it closes properly under the engine.

Only in rare cases does a cylinder head need to be replaced. In most cases, cylinder head defects are associated with easily replaceable parts, such as valves.