Combustion engine valvetrains have evolved over time. While flathead and overhead valve designs were more popular in the past, most modern engines run overhead cam designs. Three common combustion ...

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.

It seems, for the modern American production car. that the 'L' head engine is a thing of the past. Present design trends indicate that the few remaining flathead engines now in production will be ...

Overhead-valve internal-combustion engines, in which the valves are located in the cylinder head and actuated by a block-mounted camshaft via pushrods, go way back in automotive history. Production ...

Webster's Dictionary defines a camshaft simply as "a shaft bearing integral cams." A cam is defined as "a disk or cylinder having an irregular form such that its rotary motion gives to a part or parts ...