Cosworth DFV
kW) | |
---|---|
Torque output | 221–280 lb⋅ft (300–380 N⋅m) |
Dimensions | |
Dry weight | 168 kg (370.4 lb) |
Chronology | |
Successor | Ford-Cosworth HB |
The DFV is an
Its development in 1967 for
The engine is a 90°, 2,993 cc V8 with a bore and stroke of 85.67 × 64.90 mm (3.373 × 2.555 in) producing over 400 bhp (408 bhp at 9,000 rpm, 270 ft⋅lbf (370 N⋅m) torque at 7,000 rpm was quoted) from the start reaching over 500 bhp (510 bhp at 11,200 rpm was quoted) by the end of its Formula 1 career. The 1983 DFY variant had a revised bore and stroke of 90.00 × 58.83 mm (3.543 × 2.316 in) giving 2,993 cc and 520–530 bhp at 11,000 rpm, 280 ft⋅lbf (380 N⋅m) torque at 8,500 rpm.
Background
In 1965, the Fédération Internationale de l'Automobile, that administered Formula One racing, agreed to raise the series' maximum engine capacity from 1.5 litres (92 cu in) to 3.0 litres (183 cu in) from 1966. Up until that point, Colin Chapman's successful Team Lotus cars had relied on power from fast revving Coventry Climax engines, but with the change in regulations Coventry Climax decided for business reasons not to develop a large capacity engine.
Chapman approached Keith Duckworth, previously a gearbox engineer at Lotus but now running his fledgling Cosworth company with Mike Costin, who commented that he could produce a competitive three-litre engine, given a development budget of £100,000.[2]
Chapman approached the Ford Motor Company and David Brown of Aston Martin for funding, each without initial success. Chapman then approached Ford of Britain's public relations chief, former journalist Walter Hayes, with whom he had developed a close working relationship from the early 1960s. Since Hayes had joined Ford in 1962 the pair had previously collaborated in the production of the successful Lotus Cortina, introduced in 1963.[2] Hayes arranged dinner for Chapman with Ford employee Harley Copp, a British-based American engineer who had backed and engineered Ford's successful entry into NASCAR in the 1950s.[2] Hayes and Copp developed a business plan, which was backed by Ford UK's new chairman Stanley Gillen, and approved by Ford's Detroit head office as a two-part plan:
- Stage one would produce a four-cylinder FVA twin-cam engine for Formula Two
- Stage two would produce a V8 engine for Formula One, by May 1967
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
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
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.[5] Hayes released the DFV initially to French team 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[6] or about £90,000 in 2005 money[7]). The DFV effectively replaced the Coventry Climax as the standard F1 powerplant for the private (mostly British) teams.
The advent of
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[8] 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 1978, Alan Jones in 1980, Nelson Piquet in 1981 and Keke Rosberg in 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
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
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 BHP at around 11,000 RPM by the early 1980s, which meant the power deficit to the turbocharged Renaults and Ferraris was only around 30–40 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 equivalent to £122,000 in 2023.[10]
Other formulae
Sportscar racing
The DFV was used in
1976 saw a slightly faster pace for the Mirage and the DFV-powered De Cadenet Lola, but they were eclipsed by the new turbocharged Porsche 936, driven by Ickx and Gijs van Lennep, in first place. After two years with DFV-powered vehicles failing to run competitive distances, a DFV-powered Rondeau was the surprise winner in the 1980 race. Jean Rondeau and Jean-Pierre Jaussaud nursed a two lap lead over the Jacky Ickx / Reinhold Joest Porsche 908/80 charging back from earlier mechanical setbacks. Another Rondeau occupied the third spot, nine laps behind the winner. In 1981 Rondeau slightly improved on the pace of the previous year but, as in 1976, DFV-powered vehicles were again outclassed by a Porsche 936, driven this time by the old Mirage winning team of Ickx and Bell. The 1981 distance result, 340 laps, was the best ever achieved with the DFV. The DFV faded from relevance over 1982–1984, showing just two finishes of over 300 laps from fourteen starts at Le Mans.
Australian race driver Bap Romano used an ex-F1 Cosworth DFV engine (formerly used by McLaren) in his Australian designed and built Kaditcha Group A Sports Car through 1983 and 1984 in the Australian Sports Car Championships. After finishing 6th in the 1983 ASCC, winning the final round of the series, he would go on to dominate the 1984 championship. The renamed Romano WE84 won four of the five rounds and in all bar heat two of the opening round when the car was a non-starter due to an accident in the first heat, scored fastest lap while also sitting on pole for every round. The DFV in the Romano was later replaced in late 1984 by the Cosworth DFL engine.
Use of post-DFV variants
1982 saw the introduction of 3.3 and 3.9 litre DFLs, endurance racing versions of the DFV, in the
Formula 3000
The DFV was also the engine for which the Formula 3000 series was created in 1985, and thus it won every race that year. The DFV and its variants continued racing in F3000 for a decade, Pedro Lamy taking the last win for a DFV in top-class motorsport, at Pau in 1993, its 65th F3000 win in 123 races.
Variants
DFW
The first variant produced from the DFV was a reduced-capacity unit for the
Formula One
The DFV had three major upgrades over its life in the top formula, with the development of first the DFY and then the DFZ, followed by a major redesign to produce the final DFR type.
DFY
kW) | |
---|---|
Torque output | 280 lb⋅ft (380 N⋅m) |
Dimensions | |
Dry weight | 150 kg (331 lb) |
With the introduction of turbocharged engines towards the end of the 1970s, Cosworth's naturally aspirated DFV began to lose its predominance. In an attempt to recover some of the performance deficit Cosworth designer Mario Illien reconfigured the cylinder aspect ratio to allow the engine to rev more freely, and combined this with a narrow-angle valve set-up and Nikasil Aluminium liners. The changes upped power output to ~520 bhp,[11] and between 11000-12000 RPM but this was not sufficient to keep pace with the turbo cars at most tracks, and it was only through a modicum of luck that Michele Alboreto was able to take what would prove to be the DFV-family's final F1 victory, at the 1983 Detroit Grand Prix. The DFY lived on with back-marker teams until the end of the 1985 season, when Cosworth switched their efforts to supporting the new turbocharged Ford GBA V6.
DFZ
kW) | |
---|---|
Torque output | 320 lb⋅ft (434 N⋅m)[13] |
Dimensions | |
Dry weight | 155 kg (342 lb) |
The announcement at end of the
The engine did however have a second brief lease of life in sportscar racing, when the FIA announced plans to transition towards using 3.5-L F1-style engines in Group C in the early 1990s. In 1990 Spice Engineering adapted its existing Group C design to take a 3.5L DFZ instead of the previously used 3.3-L DFL engine. However the new engine caused significant problems due to vibration, which resulted in the breakage of components and a significant increase in running costs - Gordon Spice estimated that the DFZ-powered car was about four times more expensive to run than the DFL-engined one.[14] The DFZ was successfully used in FIA Cup class racing in 1992, with that low-powered class being the last appearance of the DFV family in sportscar racing.
DFR
kW) | |
---|---|
Torque output | 320–400 lb⋅ft (434–542 N⋅m)[13] |
Dimensions | |
Dry weight | 155 kg (342 lb) |
Chronology | |
Successor | Ford-Cosworth HB |
From
The DFR enjoyed success in 1988 with Benetton. The team was the best performed non-turbo team of the season finishing third in the Constructors' Championship behind Ferrari (turbo) and the all-conquering McLaren-Honda. Thierry Boutsen recorded five podium finishes and Alessandro Nannini scored two podiums. The DFR was also the most powerful non-turbo of the season with a reported 620 bhp (462 kW; 629 PS). This compared to the 590 of the DFZ and the new Judd V8 with a reported 600 bhp (447 kW; 608 PS). This still lagged behind the Honda and Ferrari turbos which were producing over 650 bhp (485 kW; 659 PS) each.
The 3.5 L DFR engine was later used in the Allard J2X-C Group C sports car, in 1992.[15][16][17][18][19]
North American series
DFX
kW) | |
---|---|
Torque output | 340–490 lb⋅ft (461–664 N⋅m)[13] |
A 2.65-L
Duckworth had been a guest of the Vels Parnelli team during the Pocono victory, as
DFS
In 1986
Ford responded by commissioning Cosworth to redesign the DFX to include a number of DFR improvements. In 1989, they introduced an updated "short stroke" version of the Indy car engine which would be referred to as the "DFS" ("S" for short stroke).,[23] 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 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. However, the Kraco team merged with 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,[24] 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 XB with only one victory, that being Rahal's in 1989.
DFL
kW) | |
---|---|
Torque output | 340–510 lb⋅ft (461–691 N⋅m)[13] |
In 1981 a variant of the DFV named the DFL (for long-distance) was produced specifically for use in the new
In August 1982, a turbocharged version of this engine was tested briefly on the Brands Hatch Circuit mounted on a Ford C100.[28][29][30]
P86 750cc motorcycle engine
In 1973 Norton approached Cosworth to help build a new engine that could be used for both street and racing motorcycles. The idea was to create a 750-cc parallel-twin version of the DFV, with liquid-cooling, 4-valve head, dual overhead cams and flat combustion chambers.[31] Expected power was to be 65–75 hp for road bikes, and at least 100 hp for the racing bikes.[31]
The P86 had a bore of 85.6 mm and a stroke of 64.8 mm, giving a capacity of 746 cc.[31] A timing belt was used to drive the cams, rather than the gear train used on the DFV.[31] The P86 shared the same combustion chamber, head designs, pistons and rods from the DFV.[31]
Norton specified that the P86 must run through a single carburettor source, which led to a 360° firing interval, with both pistons rising and falling as a pair.[31] As this led to increased vibration, a dual counterbalancing system was developed, in conjunction with a heavy flywheel.[31] In an engine weighing 195 lb, 75 lb of that was a rotating mass inside, which was a lot of inertia to be driven.[31]
The P86 had downdraught ports like the DFV, but used two Amal carburettors, rather than the fuel injection of the DFV. The carburettors and angle in relation hampered fuel delivery and power output.[31]
Dyno testing showed that the P86 developed 90 hp, down on the projected 100 hp, while the massive amount of rotating weight inside the engine (counter balancers and flywheel) hindered throttle response.[31] The overall weight of the engine meant that it was never going to be as light as equivalent engines from Japanese manufacturers. The belt driven timing system was inaccurate, while the belts themselves were fragile and prone to breaking.[31]
The P86 was fitted in a Norton 'frameless' chassis that made its racing debut in 1975, but results were poor, due to the lack of power. When Norton Villiers Triumph was split up in 1976, an offshoot company called NVT Engineering disbanded the testing and racing departments, and the existing bikes and spare engines (30 in total) were sold off.[31]
The P86 made a brief comeback 10 years later at the 1986 Battle of the Twins, held at the Daytona International Speedway. The Quantel entry featured one of the surviving P86 engines – reworked, fitted with fuel injection and bored out to 823 cc.[31] Ridden by Paul Lewis, the Quantel finished 2nd, and would win the event in 1988 ridden by Roger Marshall.[31][32]
Major successes
DFV normally aspirated 3.0-litre 90° V8
Formula One Drivers' Champions (12):
- 1968 Graham Hill (Team Lotus)
- 1969 Jackie Stewart (Matra)
- 1970 Jochen Rindt (Team Lotus)
- 1971 Jackie Stewart (Tyrrell)
- 1972 Emerson Fittipaldi (Team Lotus)
- 1973 Jackie Stewart (Tyrrell)
- 1974 McLaren)
- 1976 McLaren)
- 1978 Mario Andretti (Team Lotus)
- 1980 Williams)
- 1981 Nelson Piquet (Brabham)
- 1982 Williams)
Formula One Constructors' Champions (10):
- 1968 Lotus
- 1969 Matra
- 1970 Lotus
- 1971 Tyrrell
- 1972 Lotus
- 1973 Lotus
- 1974 McLaren
- 1978 Lotus
- 1980 Williams
- 1981 Williams
- 1975 Derek Bell(Mirage),
- 1980 Jean Rondeau/Jean-Pierre Jaussaud (Rondeau)
Formula 3000 Champions (6):
- 1985 Christian Danner (March Engineering)
- 1986 Ivan Capelli (March Engineering)
- 1987 Stefano Modena (March Engineering)
- 1988 Roberto Moreno (Reynard)
- 1992 Luca Badoer (Reynard)
DFX turbocharged 2.65-litre 90° V8
- 1978 Al Unser (Lola)
- 1979 Penske)
- 1980 Johnny Rutherford (Chaparral)
- 1981 Penske)
- 1982 Gordon Johncock (Wildcat)
- 1983 Tom Sneva (March)
- 1984 Rick Mears (March)
- 1985 Danny Sullivan (March)
- 1986 Bobby Rahal (March)
- 1987 Al Unser (March)
- 1977 Penske)
- 1978 Penske)
- 1979 Parnelli*)
- 1979 Penske)
- 1980 Johnny Rutherford (Chaparral)
- 1981 Penske)
- 1982 Penske)
- 1983 Penske)
- 1984 Mario Andretti (Lola)
- 1985 Al Unser (March)
- 1986 Bobby Rahal (March)
- 1987 Bobby Rahal (Lola)
Partial Formula One Championship results
(key) (Races in bold indicate pole position) (Races in italics indicate fastest lap)
References
- ISBN 0-563-36093-3
- ^ a b c d Ludvigsen, Karl (2007). "Walter Hayes: Racing's Ultimate Insider". Atlas F1.
- ^ Howard, K. (2007) Relative values. Motor Sport, 83(7), 40–43.
- ^ Tremayne, David (January 26, 2001). "Walter Hayes – The Father of the DFV". Grandprix.com. Retrieved December 15, 2016.
- ^ "Sporting side: Ford for all". Motor. nbr 3453: 57. 24 August 1968.
- ISBN 1-85960-885-X
- ^ EH.net How much is that worth today? Archived 2006-08-21 at the Wayback Machine
- ISBN 0-7548-1509-9
- ISBN 0-7548-1509-9
- ISBN 978-0718301996.
- ^ a b c d e Robson, G. (2007) Cosworth DFV: Horses for courses. Motor Sport, 83(7), 44–48.
- ^ a b c "Engine Ford Cosworth • STATS F1".
- ^ a b c d "Horsepower and Torque Calculator| Spicer Parts".
- autosport.com. Retrieved 2 April 2016.
- ^ "1992 - 1993 Allard J2X-C - Images, Specifications and Information".
- ^ "1992 Allard J2X-C | Allard | SuperCars.net".
- ^ "Cutting Edge - 1992 Allard J2X-C". Archived from the original on 2021-11-19. Retrieved 2021-11-19.
- ^ "Mulsanne's Corner: 1992-1993 Allard J2X".
- ^ "1992 Allard J2X-C | conceptcarz.com".
- ^ "Popular Mechanics". Hearst Magazines. May 1987.
- ^ "Cosworth DFX Indy Engine".
- ^ a b c d Kirby, Gordon (March 2013). "The DFX Files". Motor Sport. Vol. 89, no. 3. pp. 114–118. Retrieved 26 September 2018.
- ^ Glick, Shav (9 March 1989). "A Cosworth Comeback Is Key to Rahal Hopes". Los Angeles Times. Retrieved 13 October 2011.
- ^ Glick, Shav (24 May 1990). "11 Buicks Will Have a Race of Their Own in Indy 500". Los Angeles Times. Retrieved 13 October 2011.
- ^ "Cosworth DFL Evolution (1981) - Racing Cars".
- ^ "Cosworth DFL (1981) - Racing Cars".
- ^ "Popular Mechanics". Hearst Magazines. January 1986.
- ^ "1981 - 1982 Ford C100 Specifications - Ultimatecarpage.com".
- ^ "Ford C100 group C (1981) - Racing Cars".
- ^ "Ford's Forgotten History: The Le Mans C100 | Classic Ford Magazine". Archived from the original on 2021-11-19. Retrieved 2021-11-19.
- ^ a b c d e f g h i j k l m n Cormier, Jason. "Norton P86 750 Challenge - Norton's Last Gasp". www.odd-bike.com. Retrieved 14 March 2019.
- ^ Lawrence, Larry (2018-05-09). "2018/05/article/archives-when-cosworth-won-at-daytona/". www.cyclenews.com. Retrieved 2023-02-23.
External links
- Darren Galpin. (June 22, 1999) Customer power: the Cosworth DFV story. 8W.