Editing Cosworth DFV (section)

===North American series===
{{Main|Ford-Cosworth Indy V8 engine}}
[[File:Cosworth DFX engine.jpg|thumb|right|200px|Cosworth DFX]]
[[File:CosworthDFSV8engine.JPG|thumb|right|200px|Cosworth DFS]]

====DFX====
{{Infobox automobile engine
|name=[[Cosworth]] DFX<ref>{{Cite web|url=https://books.google.com/books?id=y-MDAAAAMBAJ&q=cosworth+dfx+engine+rpm&pg=PA76|title = Popular Mechanics|date = May 1987|publisher = Hearst Magazines}}</ref><ref>{{Cite web|url=https://www.museumofamericanspeed.com/cosworthindyengine.html|title = Cosworth DFX Indy Engine}}</ref>
|manufacturer={{flagicon|UK}} [[Ford Motor Company|Ford]]-Cosworth
|production=1976–1987
|configuration=90° [[V8 engine|V8]]
|bore={{cvt|85.67|mm|in|lk=on}}
|stroke={{cvt|57.3|mm|in|0|lk=on}}
|displacement={{cvt|2643|cc|L|1|order=flip}}
|valvetrain=32-valve, [[DOHC]], four-valves per cylinder
|power={{cvt|720-840|hp|kW|0|lk=on}}
|torque= {{cvt|340-490|lbft|Nm|0|lk=on}}<ref name="spicerparts.com"/>
|turbocharger=[[Cosworth]]
|oilsystem=Dry sump
|fuelsystem=[[Electronic fuel injection]]
|compression= 11.2:1
|fueltype=[[Gasoline]]
}}
A 2.65&nbsp;L [[turbocharged]] version of the DFV was developed privately by the [[Vels Parnelli Jones]] team for the 1976 [[United States Automobile Club|USAC]] [[IndyCar]] season, in the face of opposition from Duckworth.<ref name=DFXfiles>{{Cite magazine|author= Kirby, Gordon |title= The DFX Files |url= https://www.motorsportmagazine.com/archive/article/march-2013/115/dfx-files |date= March 2013 |magazine= [[Motor Sport (magazine)|Motor Sport]] |volume= 89 |issue= 3 |pages= 114–118 |access-date= 26 September 2018 }}</ref> The Parnelli-Cosworth car took its first victory at the [[1976 Pocono 500]], the fifth race of the season, driven by [[Al Unser]].<ref name=DFXfiles /> Unser and his Cosworth-powered Parnelli took two further victories before the end of the year, in Wisconsin and Phoenix, and finished the championship in fourth position.

Duckworth had been a guest of the Vels Parnelli team during the Pocono victory, as [[Parnelli Jones]] and [[Vel Miletich]] wanted to establish the team as the North American distributor for the turbocharged, Indycar-specification engine.<ref name=DFXfiles /> However, shortly after the maiden race victory Cosworth poached two key engineers from the Parnelli team and set up facilities in [[Torrance, California]], to develop and market the engine themselves.<ref name=DFXfiles /> Henceforth it became known as the '''DFX'''. It went on to dominate [[American Championship car racing|American Indy car]] racing in much the same way the DFV had dominated Formula One. The engine won the [[Indianapolis 500]] ten consecutive years from 1978 until 1987, as well as winning all USAC and [[Champ Car|CART]] championships between 1977 and 1987 except for one. For a brief time in the early 1980s, some of the DFX engines were [[Rebadging|badged]] as [[Ford Performance|Ford]]s. The DFX powered 81 consecutive Indy car victories from 1981 to 1986, and 153 victories total. By the time it was replaced, the DFX was developing over {{cvt|840|bhp}}.<ref name="motorsport02" />

====DFS====
In 1986 [[General Motors|GM]] financed the British [[Ilmor]] firm to build a competitor to the DFX in [[American Championship car racing|American Indy car]] racing. [[Mario Illien]]'s [[Ilmor|Ilmor-Chevrolet Indy V-8]], which owed not a little to the DFY of five years earlier, quickly took over dominance of the sport.

Ford responded by commissioning Cosworth to redesign the DFX to include a number of DFR improvements. In 1989, they introduced an updated "short [[Stroke (engine)|stroke]]" version of the Indy car engine which would be referred to as the "'''DFS'''" ("S" for ''short stroke'').,<ref>{{cite news |url=https://www.latimes.com/archives/la-xpm-1989-03-09-sp-1544-story.html |first=Shav |last=Glick |title=A Cosworth Comeback Is Key to Rahal Hopes |date=9 March 1989 |newspaper=Los Angeles Times |access-date=13 October 2011}}</ref> and the [[Nikasil]] Aluminium liners, adopted on DFY in 1983.

The engine was fielded by two teams in its first season: Kraco Racing ([[Bobby Rahal]]) and [[Dick Simon Racing]] ([[Arie Luyendyk]]), and its development was an effort to regain dominance of the sport. At [[1989 Indianapolis 500|Indy]], neither car qualified in the front two rows, but both started in the top ten. On race day, both drivers dropped out with engine failures. Rahal won one race in 1989 at the [[Meadowlands Grand Prix|Meadowlands]]. However, the Kraco team merged with [[Galles Racing|Galles]] at season's end, dropped the program, and switched to Chevrolets.

In 1990, the factory development was continued by [[Scott Brayton]] and [[Dominic Dobson]],<ref>{{cite news |url=https://www.latimes.com/archives/la-xpm-1990-05-24-sp-380-story.html |first=Shav |last=Glick |title=11 Buicks Will Have a Race of Their Own in Indy 500 |date=24 May 1990 |newspaper=Los Angeles Times |access-date=13 October 2011}}</ref> but neither won any races. The engine was utilized by other CART teams in 1991–1992, and was retired after the introduction of the [[Ford-Cosworth Indy V8 engine|Ford Cosworth XB]] with only one victory, that being Rahal's in 1989.