Wikipedia

Straight-five engine

(Redirected fromInline-5)

Thestraight-five engine(also referred to as aninline-five engine;abbreviated I5 or L5) is apiston enginewith five cylinders mounted in a straight line along thecrankshaft.

Although less common thanstraight-four enginesandstraight-six engines,straight-five engine designs have been used by automobile manufacturers since the late 1930s. The most notable examples include the Mercedes Benz's diesel engines from 1974 to 2006 and Audi's petrol engines from 1979 to the present. Straight-five engines are smoother running than straight-four engines and shorter than straight-six engines. However, achieving consistent fueling across all cylinders was problematic prior to the adoption offuel injection.

Characteristics

edit
Animation of the 1-2-4-5-3 firing order
MAN B&W 5S50MC1,865 litre marine diesel engine

Straight-five engines are typically shorter thanstraight-six engines,making them easier to fittransverselyin an engine bay.[1]They are also smoother thanstraight-fourengines,[1]and are narrower thanV engines[2]andflat engines.

Engine balance and vibration

edit

Five-cylinder engines have acrankshaftwith 72 degree angles.[3]Amongstfour-stroke engines,an advantage of engines with five or more cylinders is that the power strokes are overlapping if the engine has an evenfiring order.[1]

A disadvantage of the odd number of cylinders in a straight-five engine is it results in imperfect primary and secondaryengine balance,unlike astraight-six enginewhich has perfect primary and secondary balance. Counterweights on the crankshaft can be used to counteract some amount of these vibrations. This method is also used instraight-four engines.[4][5]

Firing order

edit

Mostfour-strokestraight-five engines use a firing order of 1-2-4-5-3.[citation needed]This firing order results in the minimal primary (crank speed)rocking couple,and is used by theVolvo Modular engine,VW/Audi straight-five engine,General Motors Atlas engineandHonda G engine.Straight-five engines typically have a 72 degree crankshaft design.[6]

Alltwo strokestraight-five engines are limited in having a single firing order for a given crank configuration; because a complete cycle occurs every 360 degrees, there is no chance to share piston phases without having simultaneous ignitions, so the straight-five is at no disadvantage in this case. Some two-strokeoutboard engines,e.g. theMercury Marine Force 150engine use a firing order of 1-5-2-3-4.[7]

Carburettors and fuel injection

edit

The use of straight-fivepetrolengines in mass production cars only became truly viable with the advent of reliablefuel injection.This is because of the unavoidable problems of acarburettorsupplying an odd number of cylinders and the length of the inletmanifoldbetween the carburetor varying greatly between cylinders at the ends of the engine and those nearer the carburetor. Unlike other engine layouts, these problems are not easily solved by using multiple carburettors.

Diesel engineshave always used fuel injection, therefore large displacement straight-five diesel engines were commonly seen decades before straight-five petrol engines.

Usage in automobiles

edit

Diesel engines

edit

The 1938Lancia 3Rotrucks introduced a straight-five diesel engine to replace the previous straight-three engine. Built for the Italian and German armed forces during World War II and later for civilian usage, the truck remained in production until 1950.[8]

The first mass-production straight-five passenger car engine was the 1974Mercedes-Benz OM617,anaturally-aspirated3.0 L (183 cu in) engine introduced in theMercedes-Benz 300D (W114/W115)models. In 1978, aturbochargedversion was introduced in theMercedes-Benz 300SD Turbomodels. Mercedes-Benz continued to produce straight-five engines for the next 28 years, until theMercedes-Benz OM647engine ended production in 2006.

In 1978, theAudi 2.0 R5 Dengine was introduced in theAudi 100sedan. In 1983, a turbocharged version was introduced, initially for the U.S. market Audi 100. Several Volvo cars were produced with Audi straight-five diesel engines, prior to the introduction of theVolvo D5turbo-diesel engine; this engine was produced from 2001 to 2017 and was used in several diesel hybrid applications (marketed as "twin engine" models).[9][10]

Other mass-production straight-five diesel engines include the 1999–2001VM Motori 531turbo-diesel engine,[11]the 1998–2007Land Rover Td5turbo-diesel engine, the 2006–2019Ford Duratorq 3.2turbo-diesel engine and the 1998–2009Fiat JTD 2.4[broken anchor]turbo-diesel engine.

Petrol engines

edit
AnAudi 2.3 NGengine, mounted longitudinally
AVolvo B5244Sengine, mounted transversely

Henry Fordhad an inline-five engine developed in the late 1930s to early 1940s for a compact economy car design, which never saw production due to lack of demand for small cars in the United States.[12]

The first production straight-five petrol engine was theAudi 2.1 R5introduced in the Audi 100 in 1979. Audi has continued use of straight-five petrol engines (in bothnaturally aspiratedandturbochargedversions) to the present day. TheAudi TT RSandAudi RS3currently use straight-five engines.[13]In motorsport, the first car to use a straight-five engine was theAudi Quattrorally car;[14]other racing cars which used straight-five engines include the 1985-1986Audi Sport Quattro E2and the 1989Audi 90 Quattro IMSA GTO.[15][16][17][18]For the year 1987 factory team tested a 735 kW (1000 hp) version of the inline-5 powered Audi S1 Sport Quattro.[19]

Several Volkswagen-branded straight-five engines have been produced, beginning with theVolkswagen WH/WN1.9 litre 10v engine used in the 1981 Volkswagen Passat. The final Volkswagen straight-five petrol engine was theVolkswagen EA8552.5 litre 20v engine used in the North American Passat models until 2014.[20]

TheVolvo Modular enginewas introduced in the 1991 Volvo 850 sedan and was used in various Volvo models, along with theFord Focus STandFord Focus RSmodels. All of the straight-five petrol engines used by Volvo and Ford were built at the Volvo Skövde engine plant inSkövde,Sweden,until their discontinuation in 2016.

Other straight-five petrol engines include

In recent years the engine has been falling out of favour, with Volvo announcing in 2012 it would discontinue building them, for example.[21]

Usage in motorcycles

edit
See also:List of motorcycles by type of engine § Straight five

Very few motorcycles have used five-cylinder engines. However, the 1965Honda RC148and 1966Honda RC149125 cc four-stroke racing motorcycles used straight-five engines based on the 50 cc straight-twin engine from theHonda RC116Grand Prix racing motorcycle.[22][23]These straight-five engines were an unusual design in that they were configured as a straight-six engine with one of the middle cylinders removed.[24]

See also

edit
Wikimedia Commons has media related toStraight-5 engines.

References

edit
  1. ^abc"The Advantages And Disadvantages Of The Inline Five-Cylinder Engine".Car Throttle.9 February 2017.Retrieved20 August2022.
  2. ^"Inline vs V Engine - Why High End".whyhighend.Retrieved20 August2022.
  3. ^"Gimme Five".hemmings.Retrieved21 August2022.
  4. ^Robert Bosch GmbH,Bosch Automotive Handbook, 6th editionp. 459–463, Professional Engineering Publishing 2004,ISBN1-86058-474-8.
  5. ^Bednar, Fundamentals of Combustion, 1989
  6. ^https:// hemmings /blog/article/gimme-five/[bare URL]
  7. ^"150 H.P. (1989-1992) Force Outboard 1989-A THRU 1992-C CRANKSHAFT - PISTON Diagram and Parts".Archived fromthe originalon 2015-12-08.Retrieved2015-12-02.
  8. ^Storia Illustrata del Camion Italiano(in Italian). Edizione Neri. 1996.ISBN978-88-900 955-8-0.
  9. ^"V60_GBen".Ipaper.ipapercms.dk. Archived fromthe originalon 2018-09-16.Retrieved2018-05-17.
  10. ^"History of the Volvo 5 Cylinder".11 October 2017.
  11. ^"VM Motori 3.1 531 OHV engine".AutoManiac.Retrieved24 August2022.
  12. ^"Henry Ford's Weird Old Engines",Popular Science,Bonnier Corporation, p. 195, August 1960
  13. ^Sutton, Mike (2017-10-16)."400-HP 2017 Audi RS3 Tested!".Car and Driver.Retrieved2023-01-17.
  14. ^Graham Robson (2008-06-15).Audi Quattro.Veloce Publishing. p. 12.ISBN9781845841416.
  15. ^"Audi 90 quattro IMSA-GTO".classicdriver.
  16. ^"Detailed specs review of 1989 Audi 90 Quattro IMSA-GTO model for North America racing/rallye".automobile-catalog.
  17. ^"ableitet.no - Audi 90 IMSA GTO".ableitet.no.Archived fromthe originalon 2018-05-18.Retrieved2015-01-16.
  18. ^"Retrospective>> Quattro Firepower: The Imsa Audi 90 Gto - Speedhunters".26 May 2009.
  19. ^"Secret Rally Car: Audi Group S Prototype".Archived fromthe originalon 2015-01-18.Retrieved2015-01-16.
  20. ^"2014 Volkswagen Passat".cars.Retrieved24 August2022.
  21. ^Herriott, Richard (21 August 2014)."Theme – Engines: Throbby, Thrummy Quints".Driven To Write.Archivedfrom the original on 2022-06-25.
  22. ^"Honda's two-wheeled glory years".goodwood.Retrieved23 August2022.
  23. ^"The 1966 Honda RC149".Cycle News.Retrieved23 August2022.
  24. ^"RC 148 / RC149"(in Japanese).Retrieved25 October2019.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Straight-five_engine&oldid=1252956025"