Cosworth DFV
The DFV is an internal combustion engine that was originally produced by Cosworth for Formula One motor racing. The name is an abbreviation of Double Four Valve, the engine being a V8 development of the earlier four-cylinder FVA, which had four valves per cylinder.
Its development in 1967 for Colin Chapman's Team Lotus was sponsored and funded by major American automotive manufacturer Ford. For many years it was the dominant engine in Formula One, with the whole engine program funded by Ford's European division, Ford Europe and engines badged as "Ford" for Formula One championship races. DFVs were widely available from the late 1960s to the mid 1980s and were used by every specialist team in F1 during this period with the exception of Ferrari, Alfa Romeo, Renault, BRM and Matra, who all designed, produced and ran their own engines. Variants of this engine were also used in other categories of racing, including CART, Formula 3000 and sports car racing.
The engine is a 90°, 2,993 cc V8 with a bore and stroke of 85.67 × 64.90 mm. It reliably produced over 400 bhp, specifically reaching 408 bhp at 9,000 rpm, and of torque at 7,000 rpm. By the end of its Formula 1 career, it achieved over 500 bhp, with a peak of 510 bhp at 11,200 rpm.
The 1983 DFY variant had an updated bore and stroke of 90.00 × 58.83 mm, maintaining a displacement of 2,993 cc. It produced 520–530 bhp at 11,000 rpm and of 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 to 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.
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. 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. 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
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 BRM complex and too heavy; the Maserati unreliable; the Honda overweight; while Dan Gurney's Weslake motor was powerful but unreliable. 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. Hayes released the DFV initially to British team Matra International, 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. The DFV effectively replaced the Coventry Climax as the standard F1 powerplant for the private 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
Lotus, McLaren, Matra, Brabham, March, Surtees, Tyrrell, Hesketh, Lola, Williams, Penske, Wolf and 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 aerodynamics on the F1 scene in 1977 provided a new lease of life for the now decade-old engine. The principle relied on Venturi tunnels on the underside of the car to create low pressure regions and thus additional downforce. Previously, teams running Ferrari and 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 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, Alan Jones in, Nelson Piquet in and Keke Rosberg in 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 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 the Renault, Ferrari and Toleman were unable to offer consistent opposition to the Cosworth DFV British teams. The early turbo Renault, though powerful 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 Buenos Aires, Silverstone, 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. Michele Alboreto took the DFV's last F1 win in a Tyrrell at the in 1983, and Martin Brundle was the last person to race in F1 with a DFV, also in a Tyrrell at the 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 510BHP at around 11,000RPM by the early 1980s, which meant the power deficit to the turbocharged Renaults and Ferraris was only around 30–40BHP 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.