How Do Different Cams Improve Performance?

[Corey]

From what I hear…a cam changes timing or something.
What does this mean, exactly?

As the car stands stock, the cam rotates and pushes the valve down an optimal length.
If you want your car to rev faster, wouldn’t that mean the cam would spin faster, but not be able to push the valve down as far as possible?

The only way I can think of a cam improving performance is…
Having a thinner cam (so it does more rotations faster), with longer lobes to push the valve down further.
Kind of like installing a smaller pulley on a supercharger. It’ll rotate faster than a larger pulley.

Am I thinking of this entirely wrong?

Topic

[college man]

A bigger cam will provide more valve lift and keep the intake open
a little longer for better cylinder filling. which equates to more
power.

[dave]

you are essentially trading low-end (idle) performance for longer valve lift and duration. so your car will run like crap at idle, but will fly at high rpm.

[Author]

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