Last month's "How It Works" story gave you the basics of the four-stroke cycle, describing the motion of the intake and exhaust valves in relation to the piston moving up and down in the cylinder.

Nothing determines the "personality" of an engine more than the camshaft. Think of the cam as a mechanical computer, calling the shots on when and how the valves open and close. That computer is ...

It's been all the talk on internet forums, club meeting hangouts, and in enthusiast garages across the nation—the loss of zinc and other protective "barrier" chemicals in modern oil damaging ...