The piston acceleration is directly proportional to the magnitude of the G-forces experienced by the piston-connecting rod assembly. The acceleration, or rate of change in piston velocity, is the limiting factor. Straying into this area usually does not mean instant engine failure, but may increase the chances of damaging the engine. Operating an engine in this area is known as redlining. The actual term redline comes from the red bars that are displayed on tachometers in cars starting at the rpm that denotes the redline for the specific engine. The word is also used as a verb, meaning to ride or drive an automotive vehicle above the redline. The redline of an engine depends on various factors such as stroke, mass of the components, displacement, composition of components, and balance of components. Redline refers to the maximum engine speed at which an internal combustion engine or traction motor and its components are designed to operate without causing damage to the components themselves or other parts of the engine. Tachometer showing red lines above 14,000 rpm. ( Learn how and when to remove this template message) JSTOR ( September 2008) ( Learn how and when to remove this template message).Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. This article needs additional citations for verification.
