Valvetrain

Cutaway of a dual overhead camshaft engine
1969 AMC V8 overhead valve engine. The rocker cover has been removed, so the pushrods, rocker arms, valve springs, and valves are visible.

A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine.[1] The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combustion chamber, while the exhaust valves control the flow of spent exhaust gases out of the combustion chamber once combustion is completed.[2]

  1. ^ Brain, Marshall (5 April 2000). "How Car Engines Work". HowStuffWorks. Retrieved 29 January 2014.
  2. ^ "Sci-Tech Dictionary: "valvetrain"". Answers.com. Retrieved 29 January 2014.