valve overlap

The portion of the operating cycle of a reciprocating engine in which, when the piston is passing TDC (top dead center) on the exhaust stroke, both the intake and exhaust valves are open. Valve overlap increases the efficiency of the engine operation by allowing the low pressure caused by the exhaust gases leaving the cylinder to help the fresh charge of fuel-air mixture in the induction system to start moving into the engine.

Aviation dictionary. 2014.

Look at other dictionaries:

  • valve overlap — A certain period in which both the intake and exhaust valve are partially open. The intake is starting to open while the exhaust is not yet closed. It is usually expressed in degrees of crankshaft rotation and determined by the valve timing,… …   Dictionary of automotive terms

  • valve — A device used to either open or close an opening to allow or prevent the flow of a liquid or gas from one place to another. There are many different types. See ABS relay valve accumultor valve air valve carburetor air control valve air gulp valve …   Dictionary of automotive terms

  • overlap — [1] The part of the spray band that covers the previous application of paint. A 50% overlap on each stroke is generally recommended. [3] Extension of the weld face metal beyond the toe of the weld. [2] The number of degrees of crankshaft rotation …   Dictionary of automotive terms

  • Valve amplifier — A valve amplifier or tube amplifier is a type of electronic amplifier that make use of vacuum tubes instead of solid state semiconductor devices (such as transistors). As any other electronic amplifier they serve to increase the power and/or… …   Wikipedia

  • Valve audio amplifier — A valve (UK) audio amplifier or vacuum tube (US) audio amplifier is a valve amplifier used for sound recording, reinforcement, or reproduction. Until the invention of solid state devices such as the transistor, all electronic amplification was… …   Wikipedia

  • Continuous variable valve timing — offers a unique ability to have independent control of the intake and exhaust valves in an internal combustion engine. For any engine load criteria, the timing of intake and exhaust can be independently programmed [1]. The main variations of… …   Wikipedia

  • Piston valve — A piston valve is a device used to control the motion of a fluid along a tube or pipe by means of the linear motion of a piston within a chamber or cylinder.Examples of piston valves are: * The valves used in the valve gear of many stationary… …   Wikipedia

  • Houston valve — Infobox Anatomy Name = PAGENAME Latin = plicae transversae recti GraySubject = 249 GrayPage = 1183 Caption = Coronal section of rectum and anal canal. Caption2 = Anatomy of the anus and rectum System = MeshName = MeshNumber = DorlandsPre = p 24… …   Wikipedia

  • MIVEC — (Mitsubishi Innovative Valve timing Electronic Control system)[1] is the brand name of a variable valve timing (VVT) engine technology developed by Mitsubishi Motors. MIVEC, as with other similar systems, varies the timing of the intake and… …   Wikipedia

  • Manifold (automotive) — In automotive engineering, an intake manifold or inlet manifold is the part of an engine that supplies the fuel/air mixture to the cylinders. An exhaust manifold or header collects the exhaust gases from multiple cylinders into one pipe. The word …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.