6D140 - 3 Used Engine Heads For Excavator PC650 - 7 6217 - 11 - 1113

Specification

Description

Cylinder Head Valves

Valve guide- the valve guide simply guides the valve. Valve guides are the metal pieces, usually iron or bronze, that position and allow for free movement of valves. The guides are usually removable parts, pressed into the cylinder head during installation. This makes replacing them during cylinder head refurbishment easy.

Valve seat- this part provides a seat that the valve makes contact with to form a seal. Together with the valve, the cylinder head valve seat prevents combustion gasses from escaping until the valve opens. Seat valves are made from hardened iron alloy and forcefully driven into the cylinder head to create an airtight seam.

Spring seat- some cylinder heads contain a spring seat. The spring seat is usually placed between the spring and the surface of the cylinder head. It protects the head from being damaged by the spring as it compresses and expands. These parts are often found on aluminum heads.

Valve lifter and rocker arm- a valve lifter is the component that opens and closes a valve. It is worked by the camshaft. In an OHC cylinder head, the lifter pushes against the valve directly. The lifter used on a pushrod engine actuates the rocker arm which, in turn, opens the valve. Valve lifters are used on the intake and  exhaust valves.

Cylinder Head Combustion Chamber

The cylinder head parts list cannot be complete without mentioning the combustion chamber. This part can be said to be the core of the engine. The cylinder head combustion chamber is where the air/fuel mixture burns to produce the power to move a vehicle.

Combustion chambers take different shapes and sizes. It depends on the type of engine and vehicle application. The chamber comprises the cylinder head with its ports and valves, the cylinder and cylinder walls, and the piston with its connecting rod.