Red marquis at 10:45, 13 November 2008

2008-11-13T10:45:05Z

← Older revision		Revision as of 10:45, 13 November 2008
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	[[thumb\|250px\|One complete cycle of a four cylinder, four stroke engine. The volume displaced is marked in orange.]]		[[Image:Displacement.gif\|thumb\|250px\|One complete cycle of a four cylinder, four stroke engine. The volume displaced is marked in orange.]]
	'''Engine displacement''' is the volume swept by the piston(s) in a single movement. In the very familiar [[four-stroke]] [[piston engine]] (but also in the [[two stroke engine]]) this is the volume that is ''swept'' as the [[piston]](s) move from ''top dead center'' to ''bottom dead center''. It can be specified in cubic centimeters, liters, or cubic inches. An engine's displacement is a basic mechanical feature such that, all other factors being equal, more engine displacement means more horsepower.		'''Engine displacement''' is the volume swept by the piston(s) in a single movement. In the very familiar [[four-stroke]] [[piston engine]] (but also in the [[two stroke engine]]) this is the volume that is ''swept'' as the [[piston]](s) move from ''top dead center'' to ''bottom dead center''. It can be specified in cubic centimeters, liters, or cubic inches. An engine's displacement is a basic mechanical feature such that, all other factors being equal, more engine displacement means more horsepower.

Red marquis at 10:43, 13 November 2008

2008-11-13T10:43:32Z

← Older revision		Revision as of 10:43, 13 November 2008
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	The engine's displacement is often used in the manufacturers nomenclature. For instance, the BMW 528 is a 5-series car with a 2.8 litre engine and Nissan's [[Nissan Teana\|Teana 350JM]] is a Teana with a 3498cc (213.5 CID) [[Nissan VQ engine#VQ35DE\|engine]]. Motorcycles are often labelled this way.		The engine's displacement is often used in the manufacturers nomenclature. For instance, the BMW 528 is a 5-series car with a 2.8 litre engine and Nissan's [[Nissan Teana\|Teana 350JM]] is a Teana with a 3498cc (213.5 CID) [[Nissan VQ engine#VQ35DE\|engine]]. Motorcycles are often labelled this way.
	~~==Calculation==~~
	~~Engine displacement is calculated using the [[bore (engine)\|bore]], [[stroke (engine)\|stroke]], and number of [[cylinder (engine)\|cylinders]]:~~
	~~:<math> \mbox{displacement} = {\pi\over 4} \times \mbox{bore}^2 \times \mbox{stroke} \times \mbox{number of cylinders}</math>~~
	==Units of measure==		==Units of measure==
	The cubic inch was often formerly used (until the 1980s) to express the displacement of engines for new cars, trucks, etc. (e.g., the "426" in ''426 HEMI'' refers to 426 cubic inches displaced). It is therefore still used for this purpose in the context of the classic-car hobby, auto racing, and so forth. The auto industry nowadays uses SI for this purpose (e.g. 6.1 L HEMI). However, the actual displacement measurements of an engine are still given by many manufacturers in cubic inch displacement (usually along with cc; e.g. the 6.1 L HEMI's published displacement is 370.0 CID/6,059 cc).<ref>		The cubic inch was often formerly used (until the 1980s) to express the displacement of engines for new cars, trucks, etc. (e.g., the "426" in ''426 HEMI'' refers to 426 cubic inches displaced). It is therefore still used for this purpose in the context of the classic-car hobby, auto racing, and so forth. The auto industry nowadays uses SI for this purpose (e.g. 6.1 L HEMI). However, the actual displacement measurements of an engine are still given by many manufacturers in cubic inch displacement (usually along with cc; e.g. the 6.1 L HEMI's published displacement is 370.0 CID/6,059 cc).<ref>

Red marquis at 10:42, 13 November 2008

2008-11-13T10:42:40Z

New page

[[thumb|250px|One complete cycle of a four cylinder, four stroke engine. The volume displaced is marked in orange.]]
'''Engine displacement''' is the volume swept by the piston(s) in a single movement. In the very familiar [[four-stroke]] [[piston engine]] (but also in the [[two stroke engine]]) this is the volume that is ''swept'' as the [[piston]](s) move from ''top dead center'' to ''bottom dead center''. It can be specified in cubic centimeters, liters, or cubic inches. An engine's displacement is a basic mechanical feature such that, all other factors being equal, more engine displacement means more horsepower.

Alternatively, displacement must sometimes be defined as the total volume of air/fuel mixture an [[engine]] draws in during one complete engine cycle, howsoever defined and subject to further interpretation by taxation and racing authorities.

The engine's displacement is often used in the manufacturers nomenclature. For instance, the BMW 528 is a 5-series car with a 2.8 litre engine and Nissan's [[Nissan Teana|Teana 350JM]] is a Teana with a 3498cc (213.5 CID) [[Nissan VQ engine#VQ35DE|engine]]. Motorcycles are often labelled this way.
==Calculation==
Engine displacement is calculated using the [[bore (engine)|bore]], [[stroke (engine)|stroke]], and number of [[cylinder (engine)|cylinders]]:
:<math> \mbox{displacement} = {\pi\over 4} \times \mbox{bore}^2 \times \mbox{stroke} \times \mbox{number of cylinders}</math>
==Units of measure==
The cubic inch was often formerly used (until the 1980s) to express the displacement of engines for new cars, trucks, etc. (e.g., the "426" in ''426 HEMI'' refers to 426 cubic inches displaced). It is therefore still used for this purpose in the context of the classic-car hobby, auto racing, and so forth. The auto industry nowadays uses SI for this purpose (e.g. 6.1 L HEMI). However, the actual displacement measurements of an engine are still given by many manufacturers in cubic inch displacement (usually along with cc; e.g. the 6.1 L HEMI's published displacement is 370.0 CID/6,059 cc).<ref>

{{cite web |url=http://www.dodge.com/bridge/vehsuite.html?app=vehiclespecs&family=charger&model=Technical&zipcode=90210&year=2008 |title=2008 Dodge Charger – Specs & Upgrades |accessdate=2008-05-02 |publisher=Chrysler}}</ref><ref>{{cite web |url=http://www.fordvehicles.com/trucks/f150/features/specs/ |title=Ford Vehicles: Get Specifications F-150 |accessdate=2008-04-25 |author= |date= |work= |publisher=Ford Motor Company|quote=Engine type: 5.4L Triton® SOHC 24-valve V8... Displacement (cu. in.): 330 CID}}</ref><ref>{{cite web |url=http://www.chevrolet.com/silverado/specifications/ |title=Chevrolet 2008 Silverado Pickup Truck - Specifications (under engine 'tab')|accessdate=2008-04-25 |author= |date= |work= |publisher=GM |quote=Engine: Vortec 5.3L Aluminum-Block V8...Displacement (cu. in.): 325}}</ref><ref>{{cite web |url=http://www.dodge.com/bridge/vehsuite.html?app=vehiclespecs&family=ram_2500&model=Technical&zipcode=48226&year=2008 |title=Dodge Specifications |accessdate=2008-04-25 |author= |date= |work= |publisher=Chrysler LLC|quote=Powertrain: Engine - Displacement - Cubic Inches: 345.0}}</ref> Some examples of common CID-to-litre conversions are given below. Note that nominal sizes are not always precisely equal to actual sizes. This principle is frequently seen in engineering, tool standardization, etc. (for ease of use) and in marketing (when a big round number sounds more impressive, is more memorable, etc.).

{| class="wikitable"
!Make (±Division)!!CID (actual) (nearest 1)!!CID (nominal)!!SI (actual) (nearest 0.01)!!SI (nominal)
|-
|Honda, Kawasaki, others||something close to 61 CID||NA (not marketed in CID)||[something close to SI nominal]||1000 cc (= 1.0 L)
|-
|Honda, Kawasaki, others||something close to 98 CID||NA (not marketed in CID)||[something close to SI nominal]||1600 cc (= 1.6 L)
|-
|Honda, Kawasaki, others; Ford||something close to 122 CID||NA (not marketed in CID)||[something close to SI nominal]||2000 cc (= 2.0 L)
|-
|GM (Pontiac, Buick, Oldsmobile, GMC, others)||151 CID||NA (not marketed in CID)||[something close to SI nominal]||[[GM Iron Duke engine|2.5 L]]
|-
|Toyota, Ford, Chrysler, others||something close to 183 CID||NA (not marketed in CID)||[something close to SI nominal]||3.0 L
|-
|AMC, Jeep, Chrysler ([[AMC_Straight-6_engine#4.0|I6]])|| 241.573 CID||242 CID||3,959 cc||4.0 L
|-
|Ford||something close to 244 CID||NA (not marketed in CID)||[something close to SI nominal]||[[Ford Cologne V6 engine#4.0|4.0 L]]
|-
|Ford (Ford, Mercury)||[something close to CID nominal]||250 CID||4.10 L||4.1 L
|-
|AMC, Jeep, International Harvester||[something close to CID nominal]||258 CID||4.22 L||4.2 L
|-
|Ford (Ford, Mercury)||[something close to CID nominal]||[[Ford Windsor engine|289 CID]]||4.74 L||NA (not marketed in SI)
|-
|Ford (Ford trucks and vans)||[something close to CID nominal]||300 CID||4.92 L||4.9 L
|-
|Ford, GM (Chevrolet)||[something close to CID nominal]||302 CID ([[Ford Windsor engine#302|302 Windsor]], [[Ford 335 engine#302 Cleveland|302 Cleveland]], [[Chevrolet Small-Block engine#302|Chevrolet 302]])||4.95 L||5.0 L
|-
|AMC, Jeep, International Harvester||[something close to CID nominal]||304 CID||4.98 L||5.0 L
|-
|GM (Chevrolet; others?)||307 CID||[[Chevrolet Small-Block engine#307|307 CID]]||5.03 L||NA (not marketed in SI)
|-
|GM (Oldsmobile)||307 CID||NA (not marketed in CID)||5.03 L||[[Oldsmobile V8 engine#LG8|5.0 L]]
|-
|Chrysler (Chrysler, Dodge, Plymouth)||[something close to CID nominal]||[[Chrysler LA engine|318 CID]]||5.21 L||5.2 L
|-
|AMC, GM (Chevrolet)||327 CID||327 CID||5.36 L||NA (not marketed in SI)
|-
|Chrysler (Chrysler, Dodge, Plymouth)||[something close to CID nominal]||[[Chrysler LA engine|340 CID]]||5.57 L||NA (not marketed in SI)
|-
|GM (GMC, Chevrolet, Buick, Oldsmobile, Pontiac, others)||[something close to CID nominal]||[[Chevrolet Small-Block engine#350|350 CID]]||5.74 L||5.7 L
|-
|Ford (Ford, Mercury)||[something close to CID nominal]||351 CID ([[Ford 335 engine|Cleveland]] or [[Ford Windsor engine|Windsor]]) ||5.75 L||NA (not marketed in SI)
|-
|AMC, Chrysler (Chrysler, Dodge, Plymouth)||[something close to CID nominal]||[[Chrysler LA engine|360 CID]]||5.90 L||5.9 L
|-
|Chrysler (Chrysler, Dodge, Plymouth)||[something close to CID nominal]||[[Chrysler RB engine|383 CID]]||6.28 L||NA (not marketed in SI)
|-
|AMC, Ford, GM (Cadillac)||[something close to CID nominal]||390 CID||6.39 L||NA (not marketed in SI)
|-
|GM (Chevrolet)||[sometimes 396 CID, sometimes 402 CID]||[[Chevrolet Big-Block engine#396 and 402|396 CID]]||6.49 L||NA (not marketed in SI)
|-
|GM (Chevrolet; others?)||[something close to CID nominal]||[[Chevrolet Small-Block engine#400|400 CID]]||6.55 L||NA (not marketed in SI)
|-
|GM (Chevrolet)||[something close to CID nominal]||[[Chevrolet Big-Block engine#409|409 CID]]||6.70 L||NA (not marketed in SI)
|-
|GM (Pontiac)||[something close to CID nominal]||421 CID||6.90 L||NA (not marketed in SI)
|-
|Chrysler (Chrysler, Dodge, Plymouth)||[something close to CID nominal]||426 CID ([[Chrysler RB engine|Wedge]] or [[Chrysler Hemi engine|Hemi]])||6.98 L||7.0 L
|-
|Ford (Ford, Mercury)||[something close to CID nominal]||[[Ford FE engine|427 CID]]||7.00 L||7.0 L
|-
|Ford (Ford, Mercury)||[something close to CID nominal]||[[Ford FE engine|428 CID]]||7.01 L||7.0 L
|-
|Ford (Ford, Mercury)||[something close to CID nominal]||[[Ford 385 engine|429 CID]]||7.03 L||7.0 L
|-
|Chrysler (Chrysler, Dodge, Plymouth)||[something close to CID nominal]||[[Chrysler RB engine|440 CID]]||7.21 L||7.2 L
|-
|GM (GMC, Chevrolet)||[something close to CID nominal]||[[Chevrolet Big-Block engine#454|454 CID]]||7.44 L||7.4 L
|-
|GM (Buick, Oldsmobile, Pontiac)||[something close to CID nominal]||455 CID||7.46 L||NA (not marketed in SI)
|-
|Ford (Ford [trucks and vans]; Lincoln [cars])||[something close to CID nominal]||[[Ford FE engine|460 CID]]||7.54 L||7.5 L
|-
|GM (Cadillac)||[something close to CID nominal]||472 CID||7.73 L||7.7 L
|-
|GM (Cadillac)||[something close to CID nominal]||500 CID||8.19 L||8.2 L
|-
|Chrysler (Dodge)||506.5 CID||505 CID||8285 cc||8.3 L
|-
|Chrysler (Dodge)||509.8 CID||510 CID||8354 cc||8.4 L
|}

==Governmental regulations==
Taxation of [[automobile]]s is commonly based on engine displacement, rather than power output. Displacement is basic to an engine design whereas power output depends a great deal on other factors, including wear and even the weather. This has encouraged the development of other methods to increase engine power, such as [[variable valve timing]] and [[turbocharger]]s.

There are four major regulatory constraints for automobiles: the European, the British, the Japanese, and the American. The method used in some European countries, and which predates the EU, has a level of taxation for engines over one (1.0) liter and another at the level of about 100 cubic inches, which is approximated to 1.6 liters. The British system of taxation depends upon vehicle emissions for cars registered after 1 March 2001 but for cars registered before this date it depends on engine size. Cars under 1549 cc qualify for a cheaper rate of tax.<ref>[http://www.direct.gov.uk/Motoring/OwningAVehicle/HowToTaxYourVehicle/HowToTaxYourVehicleArticles/fs/en?CONTENT_ID=10012524&chk=X2gG9G The Cost of Vehicle Tax for Cars, Motorcycles, Light Goods Vehicles and Trade Licences]." ''Direct.gov.uk''</ref>

The Japanese is similar to the European taxation by classes of displacement, plus a vehicle weight tax. In the American system, which includes Canada, Australia and New Zealand, there is not this sort of taxation per engine displacement. In The Netherlands and Sweden, road tax is based on vehicle weight. However, Swedish cars which was registered in 2008 or later, have it's tax based on its carbon dioxide emissions.

Displacement is also used to distinguish categories of (heavier) motorbikes with respect to license requirements. In France and some other EU countries, mopeds, usually with a [[two-stroke engine]] and less than 50 cm<sup>3</sup> displacement can be driven with minimum qualifications (previously, they could be driven by any person over 14). This led to all light motorbikes having a displacement of about 49.9 cm<sup>3</sup>. Some people [[engine tuning|tuned]] the engine by increasing the cylinder bore, increasing displacement; such mopeds cannot be driven legally on public roads since they do no longer conform to the original specifications and may go faster than 45 km/h.

[[Wankel engine]]s, due to the amount of power and emissions they create for their displacement, are generally taxed as 1.5 times their actual physical displacement (1.3 liters becomes 2.0, 2.0 becomes 3.0), although actual power outputs are far greater (the 1.3 liter 13B can produce power comparable to a 3.0 V6, and the 2.0 liter 20B can produce power comparable to a 4.0L V8). As such, racing regulations actually use a much higher conversion factor.

==See also==
* [[Active Fuel Management]]
* [[compression ratio]]
* [[engine tuning]]
* [[variable displacement]]

==References==

<references/>

[[Category:Engine technology|Displacement]]

Engine displacement - Revision history

Red marquis at 10:45, 13 November 2008

Red marquis at 10:43, 13 November 2008

Red marquis at 10:42, 13 November 2008