By Brian Roberts
The cylinder head is the most complicated area of the engine to seal. It requires a medium that can seal oil, coolant and combustion. Special materials have been developed by gasket manufacturers to handle these fluids and gasses. The two most common head gasket designs today are the composite (rarely used anymore) and the MLS (Multi-Layered Steel) gasket, which most manufacturers use today. Since rebuilders work on a variety of engines, they will encounter both designs all the time.