Select Year: Select Make:

How does a Cylinder Head work? 

For engines that are powered by internal combustion engines, the cylinder head plays an essential role in how the engine operates. An internal combustion engine is powered by a small explosion. This explosion is created by a fuel, like gasoline, which is mixed with air in a combustion chamber which is generally a very small space. To create the explosion, a spark plug is implemented; it generates a spark which creates a dramatic expansion in the air pressure levels in the combustion chamber. A piston within the engine then acts as a carrier of this pressure, which then causes it to move; this contributes to the needed mechanical energy of the engine.


Cylinders are the parts which allow the pistons to move in the internal combustion engine. Pistons are in rapid constant motion during the function of the engine. The positioning of several cylinders in a row is what is known as an engine block; it is made of a molded heavy-duty metal such as aluminum or cast iron. Constant movement of these pistons inside the cylinders make it necessary to have the cylinders coated with a more wear-resisting lining.


The upper deck of the engine block is where the cylinder head resides. It hosts the top of the combustion chamber along with the spark plugs and the valves.  These reside among numerous internal passageways which function to allow the air and fuel to get to the combustion chamber. These passageways also allow exhaust fumes to be released from the combustion chamber to the exhaust valves. Coolants such as anti-freeze also use these passageways to aid in the reduction of engine temperatures. To avoid damage to the engine, these coolants are needed, because constant heat is being created in the process of internal combustion

Component Protection

Use of a valve cover is implemented to protect the valve train parts from the spraying of valve lubricants and hinder the escape of toxic fumes into the environment


Cylinder heads are predominantly made of either aluminum or cast iron. The deck of the cylinder block is where it is firmly bolted to create a tight seal; this prevents the pressure of the explosion from escaping from the combustion chamber. Essential to the cylinder heads design are mounting points which position and hold the spark plugs, the valve train assembly, exhaust and intake ports or carbon emission and oxygen intake.