Table of Contents
Why does the exhaust valve need a wider seat?
Since exhaust valves operate at extreme temperatures, they require a wider seat to conduct heat away from the valve through the seat. Each time the valve seat is machined, >> material is removed and the seat “sinks” into the head, moving deeper into the port.
What is the function of the inlet and exhaust valves?
Intake and exhaust valves are responsible for controlling the flow of gases through the combustion chamber. Intake valves let air in, whereas exhaust valves let air out. They are shaped to have a slim stem leading to a flatter face, with the intake valves often being larger than the exhaust.
Why is the design of exhaust valve more critical than that of an inlet valve?
Because intake valves are virtually cooled by fresh air, however exhaust valves are subjected to a very high temperature burnt gases. Because of that it can be exposed to very high thermal stresses more than intake valves and hence there are more chances of failure of exhaust valves rather than intake valves.
Why does each valve have two valve springs?
Dual Springs are a good option for performance engines with a heavy valvetrain. The two springs rub against each other and act as a damper. The second spring also acts as a safety measure. Broken springs can be found before they drop a valve into the engine.
Why should the valve seat be no wider than 1.5 mm?
The width of a valve seat is important. A narrow seat is desirable to give a good seal, while a wider seat is needed to transfer heat from the valve head to the cylinder head. A compromise is therefore necessary, with the intake valve seat usually being narrower than the exhaust valve seat. Exhaust valve 1.8 to 2.5 mm.
What is an exhaust valve seat?
The valve seat in an internal combustion gasoline or diesel engine is the surface against which an intake or an exhaust valve rests during the portion of the engine operating cycle when that valve is closed.
Why do valves need springs?
The springs help to protect the axle, cylinder walls, pistons, and the bearings of the engine because they force the valves to completely close, securing the proper amount of compression.