The Engine Valve

The engine valve is needed for the engine to run correctly. The intake and exhaust valves need to open at the right time, or the engine will not work. In the Four Stroke Cycle the intake stroke is the 1st stroke and exhaust stroke is the 4th stroke.


Here are engine valve terms & Diagram:


Head - top of the valve
Margin - top piece of the valve this is the head
Face - Piece on the valve that touches the engine block
Seat - piece on the engine that the face touches when the valve is closed Stem - the long skinny piece of the valve
Port - where the air and gas come in by an open vavle
Valve Guide - help keep the valve in place
Valve Spring - a spring that keep pressure on the valve allowing it to close
Retainer - attaches to the valve and the spring to lock the valve in place
Clearance - space between the tappet and the bottom of the valve
Lock Nut - nut that moves to provide enough clearance for valve and tappet
Adjusting Nut - nut that adjusts between the lock nut and valve to provide the proper clearance
Tappet - lifts the valve open when it is pushed up by the cam
Tappet Guide - helps keep the tappet in the proper place
Cam - lobe on the camshaft what pushes the tappet up
Camshaft - spins to open the valve as the proper time.



[Introduction] [Engine Displacement] [Piston Assembly] [Engine Lubrication] [Four Stroke Cycle]