Editing Cosworth DFV (section)

==Formula One==
The project was revealed by Hayes in a PR launch in Detroit at the end of 1965, but the engine was not ready until the third race of the 1967 season, on the 4 June at [[Circuit Park Zandvoort|Zandvoort]]. Its debut proved successful. [[Graham Hill]], who was in the team at the specific request of Ford and Hayes,<ref name=atlasF1 /> put his DFV-powered [[Lotus 49]] on [[pole position]] by half a second and led for the first 10 laps but was then sidelined by a broken gear in the camshaft drive. Team-mate [[Jim Clark]] moved up through the field in his identical car and came home to win. However, this dominant performance belied a serious fault in the timing gear.<ref>Howard, K. (2007) Relative values. ''Motor Sport'', '''83(7)''', 40–43.</ref> Clark took three more wins that season, but reliability problems left him third in the Drivers' Championship, 10 points behind champion [[Denny Hulme]]. The progress of the engine was documented in a film produced by the Ford Motor Company's film section, entitled ''[[9 Days in Summer]]''.

Initially, the agreement between Ford, Cosworth and Lotus was binding on all parties, and Ford as the funder had no plans to sell or hire the DFV to any other teams. However, it occurred to Hayes that there was no competition: the [[Ferrari]] engine was initially underpowered; the [[British Racing Motors|BRM]] complex and too heavy; the [[Maserati]] unreliable; the [[Honda]] overweight; while [[Dan Gurney]]'s [[Weslake]] motor was powerful but unreliable.<ref name=Tremayne >{{cite web|url= http://www.grandprix.com/ft/ftdt018.html |work= Grandprix.com |title= Walter Hayes – The Father of the DFV |last= Tremayne |first= David |author-link= David Tremayne |date= January 26, 2001 |access-date= December 15, 2016 }}</ref> Only Brabham's [[Repco V8]] engine provided a usable combination of power, lightness and reliability, but its age and design left little room for further improvement. Hayes concluded that Ford's name could become tarnished if the Lotus were to continue winning against only lesser opposition, and that they should agree to use the unit in other teams, and hence potentially dominate Formula One.

At the end of 1967, Copp and Hayes gently explained to Chapman that he would no longer have monopoly use of the DFV and in August 1967 it was announced that the power unit would be available for sale, via Cosworth Engineering, to racing teams throughout the world.<ref name=Motor196808>{{cite journal| title = Sporting side: Ford for all| journal = Motor| volume = nbr 3453| pages = 57 |date = 24 August 1968}}</ref> Hayes released the DFV initially to French team [[Equipe Matra Sports|Matra]], headed by [[Ken Tyrrell]] with [[Jackie Stewart]] as a driver. What followed was a golden age, where teams big or small could buy an engine which was competitive, light, compact, easy to work with and relatively cheap (£7,500 at 1967 prices<ref>Hilton, Christopher (2002) ''Ken Tyrrell – Portrait of a Motor Racing Giant'' p38 Haynes Publishing {{ISBN|1-85960-885-X}}</ref> or about £90,000 in 2005 money<ref>[http://eh.net/hmit/ppowerbp/ EH.net ''How much is that worth today?''] {{webarchive|url=https://web.archive.org/web/20060821222701/http://eh.net/hmit/ppowerbp/ |date=2006-08-21 }}</ref>). The DFV effectively replaced the [[Coventry Climax]] as the standard F1 powerplant for the private (mostly British) teams.

[[File:Cosworth DFV in Tyrrell 008.jpg|thumb|right|300px|The classic DFV engine – [[Hewland]] gearbox combination, mounted in the rear of a 1978 [[Tyrrell 008]]]]

[[Team Lotus|Lotus]], [[McLaren (racing)|McLaren]], [[Equipe Matra Sports|Matra]], [[Brabham]], [[March Engineering|March]], [[Surtees Racing Organisation|Surtees]], [[Tyrrell Racing|Tyrrell]], [[Hesketh Racing|Hesketh]], [[Lola Cars|Lola]], [[WilliamsF1|Williams]], [[Penske Racing|Penske]], [[Walter Wolf Racing|Wolf]] and [[Equipe Ligier|Ligier]] are just some of the teams to have used the DFV. In 1969 and 1973 every World Championship race was won by DFV-powered cars, with the engine taking a total of 155 wins from 262 races between 1967 and 1985.

The DFV-powered cars won also the Constructor championship, fighting with the Ferrari who won from 1975 to 1977 and in 1979.

The advent of [[ground effect in cars|ground effect]] aerodynamics on the F1 scene in 1977 provided a new lease of life for the now decade-old engine. The principle relied on [[Diffuser (automotive)|Venturi tunnels]] on the underside of the car to create low pressure regions and thus additional downforce. Previously, teams running [[Scuderia Ferrari|Ferrari]] and [[Alfa Romeo in Formula One|Alfa-Romeo]] [[flat-12]] engines had enjoyed a handling advantage due to the low centre of gravity in such a configuration. However, for ground effect, the wide engine was completely the opposite of what was required as the cylinder heads protruded into the area where the Venturi tunnels should have been.

In contrast, the V-configuration of the Cosworth engine angled the cylinders upwards and left ample space under the car for the necessary under-body profile<ref>Hughes, Mark (2004) ''The Unofficial Complete Encyclopedia of Formula 1'', p. 55, Lorenz Books, {{ISBN|0-7548-1509-9}}</ref> which massively increased downforce and gave more efficient aero balance, thus increasing cornering potential and straight line speed. Ground effect British cars and DFV engines effectively killed off the V12/flat 12 engines of Ferrari and Alfa Romeo which many pundits had believed in the mid-1970s would dominate F1 well into the mid-1980s. Drivers Mario Andretti in {{F1|1978}}, Alan Jones in {{F1|1980}}, Nelson Piquet in {{F1|1981}} and [[Keke Rosberg]] in {{F1|1982}} used a combination of British ground effect chassis and a DFV engine to claim the Drivers' Championship while DFV-powered cars took the Formula 1 Constructors' World Championship in 1978, 1980 and 1981.

The onset of the [[Turbocharger|turbo]] era in the early 1980s put an end to the DFV's F1 activities, as even with modifications the 15-year-old engine could not hope to compete with the vast power being put out by the new 1.5-litre turbocharged engines. However, in the early days of turbo F1 cars (1979–1982) the Renault, Ferrari and Toleman were unable to offer consistent opposition to the Cosworth DFV British teams. The early turbo Renault, though powerful (particularly so on high altitude tracks such as [[Autódromo José Carlos Pace|Interlagos]], [[Kyalami]], [[Circuito del Jarama|Jarama]], [[Dijon-Prenois]] and the [[Österreichring]]) were much heavier, cumbersome, complicated and significantly, much more unreliable than the British Cosworth DFV teams.

The extra power and torque of a turbo engine put much more strain on the gearbox, driveshafts and brakes on the Renaults and Ferraris, and during the early 1980s the sight of a Renault or Ferrari wilting under the strain of its extra power was a common sight. The turbo engine was also hampered by "throttle lag", a delay in throttle response which made the turbo cars very slow on tight, twisty circuits such as Monaco, Long Beach, Zolder, Montreal, Brands Hatch and Detroit, whereas the normally-aspirated Cosworth DFV enjoyed pin-sharp response and accuracy. Also, the light and agile British cars exploited ground-effect technology so well that even on fast tracks such as [[Autódromo Juan y Oscar Gálvez|Buenos Aires]], [[Silverstone Circuit|Silverstone]], [[Hockenheimring|Hockenheim]] the DFV engine was able to win. For a few years, between 1977 when Renault debuted the powerful but unreliable turbo engine and 1982 when the DFV-powered teams began to negotiate deals for turbo engines of their own, a competitive equilibrium was established.<ref>Hughes, Mark (2004) ''The Unofficial Complete Encyclopedia of Formula 1'', p. 62, Lorenz Books, {{ISBN|0-7548-1509-9}}</ref> [[Michele Alboreto]] took the DFV's last F1 win in a Tyrrell at the {{F1 GP|1983|Detroit}} in 1983, and [[Martin Brundle]] was the last person to race in F1 with a DFV, also in a Tyrrell at the {{F1 GP|1985|Austrian}} in 1985.

Some Cosworth-using constructors developed their engines in house during a Grand Prix season, such as John Nicholson's Nicholson McLaren operation or Williams F1 using John Judd's workshops to uprate the standard 480 BHP that the DFV was producing in the late 1970s/early 1980s. Uprated pistons, camshafts and valves meant Williams and McLaren's DFVs were producing over 510{{nbsp}}BHP at around 11,000{{nbsp}}RPM by the early 1980s, which meant the power deficit to the turbocharged Renaults and Ferraris was only around 30–40{{nbsp}}BHP in race trim. Since a DFV only needed a 190-litre fuel tank, compared to the 220+ litre sized fuel tank required by a turbo engine, it meant the power to weight ratio of a McLaren MP4 or Williams FW07/08 with their specialist DFV engines were comparable to their turbocharged opponents, albeit with better fuel consumption and much less strain on the rear tyres, gearboxes and rear axle, meaning softer compounds could be used and last longer by both Williams and McLaren, which gave a significant benefit to both grip and tyre durability.

As of mid-1982, 375 engines had been built. The cost of a complete engine at that time, purchased directly from Cosworth, was £27,296, approximately {{Inflation|UK|27296|1982|r=-3|fmt=eq|cursign=£}}.<ref>{{cite book |last=Lauda |first=Niki |author-link= |date=16 April 1984 |title=Second Time Around |url= |location=United Kingdom |publisher= William Kimber & Co Ltd |page=82 |isbn=978-0718301996}}</ref>