We just learned about the Exhaust Valve.
Another part of a car is the Tappet.
The tappet is the part of the car that pushes on the intake or exhaust valves to open or close them.
Remember that the camshaft is above the valves, and is a rod with cams on it spinning around.
The bump on the cam pushes on the tappet, which pushes on the pushrod, which opens or closes the valves.
(from: wikipedia - tappet)
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