Camshafts are simple devices, but important ones. Modern engines can have one or more intake and exhaust valves, and it's the camshaft's job to open valves precisely as the engine runs, supplying the ...

Three common combustion engine valvetrain designs are flathead, overhead valve (OHV), and overhead cam (OHC). Many older cars have engines with flathead or overhead valves, and these designs also tend ...

How do camshafts and valves work? The differences between DOHC, SOHC, and OHV or pushrod valve trains is explained. How the valves are related to each, and how each works. I will also speak of ...

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.