The Cylinder head is placed on the cylinder block or engine housing. It forms a part of the combustion chamber with the placement of the piston and the cylinder.

Some of its major functions are mentioned below in brief.

Functions of Cylinder head at a glance:

• It provides the mounting structure for various components (for example the inlet and outlet exhaust valves and ducts, spark plugs, etc.)

• It acts as a seal for the combustion chamber and the powerhouse for the engine’s mechanical control.

• It has the passage for coolant, engine oil, and combustion gasses.

• It dissolute the heat produced in the engine and keeps it cool.

 The cylinder head gasket lies beneath the Cylinder head. Apart from sealing the combustion chambers, the cylinder head gasket actually performs several other functions, some of them are mentioned below:

Functions of Cylinder head gasket:

1. It seals the cylinder head.

When combustion enters the cylinder, the head gasket in order to prevent the pressures created from escaping the cylinder through the space between the cylinder head and block seals the cylinder head to the engine block.

2. It seals the passage.

In order to allow the coolant and the engine oil to flow between the engine and cylinder heads, the cylinder head gasket kit seals the passage between the engine block and the cylinder heads. Moreover, these both also serve directly and sometimes control the flow of the coolant and the engine oil depending upon the application.

3. It transfers the heat.

The Cylinder head gasket helps heat to move freely among the engine block and the cylinder heads by allowing the free movement of heat throughout the gasket. 

However, due to the free movement of heat among the engine block and the cylinder heads, it also helps to distribute the heat evenly between all parts of the engine, and that results in the reduction in the concentration of heat in one part of the engine.

4. It varies the Compression Ratio.

The Compression ratio is affected by the changes in the total volume size of the cylinder with the help of the head gaskets, because some head gaskets also work as Shims (A shim is a thin and often tapered or wedged piece of material, used to fill small gaps or spaces between objects) between the engine block and the cylinder head. The cylinder heads are installed with the help of cylinder head studs.

Moreover, In the thick gaskets, the distance of the cylinder head from the block is increased due to its size. And apart from it, the compression is also decreased with the increment in the volume of the cylinder. 

On the other hand, the thin gaskets keep the cylinder head and the block together with a very thin space. Due to this, the volume of the cylinder is decreased and the compression ratio is increased simultaneously.