Valves, valve seat inserts, and valve guides

Valves, valve guides, and valve seat inserts work as an assembly to seal off the combustion chamber within the valve train. While the valve and valve seat insert perform the actual sealing function, the valve guide supports the motion of the valve.
MAHLE manufactures intake and exhaust valves in forged and hot-extruded versions in a multitude of materials for gasoline and diesel engines of every size. Depending on the stresses they are subjected to, the valves are reinforced around the seat, hardened, nitrided, or chrome-plated. Sodium-filled hollow valves can be used for extremely high thermal and mechanical loads. Since stresses on the components continue to rise in modern engines, MAHLE is focusing on the ongoing development of cooled valves.

Additional components in this assembly include the valve stem seal, the valve spring, and the top and bottom valve spring retainer.