The camshaft.
the umbo
push rods connected to the camshaft
A cam shaft generally open and closes the valves. This is a driven component by a belt or chain to the crank shaft.
no unless u r Albert Einstein
In many cars YES, but not all cars.The engines will be "Interference Engines" or "Noninterference engines"When the belt breaks in interference engines the valves strike the pistons and bend.
Blood pressure
Pneumatic valves are used to close valves in high-speed internal combustion engines, pneumatic valves are mostly to help racing engines to get to high speeds.
Generally, the more valves an engine has the more efficient it is.
Blood pressure
In a car: the cams control the opening and closing of the valves. The fact that it's "overhead" just means that the camshaft is above the cylinders instead of alongside them. In high speed engines this is considered an advantage - because of simpler linkage between the cams and the valves.
how to adjust valves on a 1050 kohler engines
For D7F 8 valve engines: Intake valves - 0.10mm, Exhaust valves - 0.20mm