You know this...too
A camshaft translates circular motion into linear motion.
Yes...the camshaft opens the valves...we all know that...
A camshaft with a lift of 0.500 inch will move a lifter or cam follower half an inch for every 2 revolutions of the engine...yes it turns at half the speed. At 2,500 RPM a lifter or cam follower with have travelled 625 inches per minute.
In a small block Chevrolet where the rocker arm ratio is 1 to 1.5 the valve will have travelled 937 inches per minute at 2,500 RPM.
Camshaft design, lobe centers, duration, lift, timing, is a discussion for another time.
When you rev up an engine think of the interaction between the camshaft (circular) and the valves (linear).
Agreed...there are still mechanical functions that remain in any engine.
You know this...but just in case!
A crankshaft translates linear motion (piston going up and down) into circular motion.
Let's say that an engine has a piston with a diameter of 4 inches, and we agree that gasoline combusting generates a pressure of 600 pounds per square inch, this piston is coming down on the power stroke with a force of 7,536 pounds or over 3 tons.
Its the reason crankshafts, main bearings caps, are strong components in any engine.
How fast does a piston that generates the linear motion travel?
For one turn of the crankshaft the piston goes down and come back up, lets assume the stoke is 3 inches the piston travels 6 inches for each revolution. The engine at 2,500 RPM the piston is travelling 15,000 inches per minute....the more a piston travels the more the friction.
When you rev up an engine think of the piston (linear motion), the crankshaft (circular motion), the pressure on the piston, and how its all held together.