Red marquis: /* See also */

2008-10-29T11:11:23Z

Red marquis at 07:14, 17 April 2008

2008-04-17T07:14:35Z

← Older revision		Revision as of 07:14, 17 April 2008
Line 1:		Line 1:
	<a ~~href=~~"~~http:~~//dk-~~drugs~~.~~com~~/~~aciphex~~.~~html">buy aciphex</~~a>		A '''naturally-aspirated engine''' or '''normally-aspirated engine''' (or "N/A" - aspiration meaning breathing) refers to an [[internal combustion engine]] (normally [[petrol]] or [[diesel]] powered) that is neither [[turbocharged]] nor [[supercharged]]. Most [[automobile]] gasoline (petrol) engines are naturally-aspirated, though turbochargers and superchargers have enjoyed periods of success, particularly in the late 1980s and the current 2000s era. However, most road-going diesel-engined vehicles use turbochargers and [[intercooler]]s, because naturally-aspirated diesels generally cannot offer suitable [[power-to-weight ratio]]s to be acceptable in the modern car market.

			Air or air/fuel mixtures are forced into the [[cylinder (engine)\|cylinder]]s by vacuum caused by cylinder movement, natural atmospheric pressure, and venturi effect upon opening of the [[poppet valve\|inlet valve]] or valves. The pressure within the cylinder is lowered by the action of the piston moving away from the valves (so as to expand the volume available for incoming air). In some cases the lowering of the cylinder pressure is enhanced by a combination of the speed of the exhaust gases leaving the cylinder and the closing of the exhaust valve at the appropriate time. A [[engine tuning\|tuned exhaust]] can help with this but generally only works at a narrow range of [[RPM\|engine speeds]] and hence is most useful in very high performance cars, aircraft and helicopters. Many N/A engines today make use of [[Variable Length Intake Manifold]]s to harness Helmholtz resonance, which has a mild forced induction effect but is not considered true forced induction.

			[[Cylinder head porting]] design is of premium importance in naturally aspirated engines. [[Camshafts]] usually will be more "aggressive", having greater lift and duration. Also, [[cylinder head]] gaskets will be thinner, and with the top of the [[piston]] rising up into the [[combustion chamber]], for high-performance N/A engines that benefit from higher [[internal combustion engines\|compression]].

			Naturally-aspirated engines generally gives less power than either turbo or supercharged engines of the same [[engine displacement]] and development level but tend to be cheaper to produce. In drag racing, naturally-aspirated vehicles are vehicles that do not operate with a blower, a turbo, nor use nitrous oxide.

			Many racing series specify N/A engines to limit power and speed. [[NASCAR]], [[Indy Racing League\|IndyCar]], and [[Formula One]] are all in this category. Naturally-aspirated engines have been mandated in Formula One since 1989, in order to curb excessive power output and the high cost of engines with superchargers or turbochargers. The [[Indy Racing League]] mandated N/A engines in 1997.

			Natural aspiration as defined above, cannot occur in a [[Two stroke#Two-stroke diesel engines\|two-stroke diesel engine]]. Therefore, some method of charging the cylinder with scavenging air must be integrated into the engine design, customarily achieved with a [[Roots blower\|positive displacement blower]] driven by the [[crankshaft]]. The blower does not act as a [[supercharger]] in this application, as it is sized to produce air flow volume in direct proportion to engine displacement and speed. A mechanically scavenged two-stoke Diesel is considered to be naturally aspirated.
			==See also==
			* [[Carburetor]]
			* [[Forced induction]]
			* [[Fuel injection]]
			* [[Manifold vacuum]]
			* [[Turbodiesel]]

			[[Category:Engines]]

218.59.163.150: buy aciphex

2008-04-16T15:01:53Z

buy aciphex

New page

<a href="http://dk-drugs.com/aciphex.html">buy aciphex</a>

← Older revision		Revision as of 11:11, 29 October 2008
Line 17:		Line 17:
	* [[Turbodiesel]]		* [[Turbodiesel]]

	[[Category:~~Engines~~]]		[[Category:Engine technology]]

Naturally-aspirated engine - Revision history

Red marquis: /* See also */

Red marquis at 07:14, 17 April 2008

218.59.163.150: buy aciphex