Cosworth DFV

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The Ford-sponsored DFV (Double Four-Valve) engine was a Formula 1 engine first produced in 1967 for Colin Chapman's Team Lotus. The engine was a 90 degree 3 litre V8, and produced over 400 bhp from the start, reaching over 500 bhp by the end of its remarkable Formula 1 career.

1 History
2 F1 variants
3 Other formulae
4 Stateside success with the DFX
5 Major successes
6 External link
7 References

[edit] History

Following the change to a 3-litre formula at the start of 1966, Colin Chapman approached the Ford Motor Company with the idea for the engine, which had to be specially made so that it could take the stresses it would face through being a structural part of the car. Ford then approached Keith Duckworth, previously a gearbox engineer at Lotus but now running his Cosworth company with Mike Costin, and paid him to design and build the engine for them.

The engine was not due to be ready until the third race of the 1967 season at Zandvoort, but its debut proved electric. Graham Hill put his DFV-powered Lotus 49 on Pole position by half a second, and Jim Clark stormed home to win. Clark took three more wins that season, but reliability problems left him 3rd in the drivers' championship, 10 points behind Denny Hulme. The progress of the engine was documented in a film produced by the Ford Motor Company's film section, entitled "Nine Days in Summer".

The engine was so competitive that at the end of 1967 Ford had to gently explain to Colin Chapman that he would no longer have a monopoly on it in 1968, but the Lotus boss took it with good grace. What followed was a golden age, where teams big or small could buy an engine which was competitive, light, compact, 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> EH.net How much is that worth today? [1]</ref>). The DFV effectively replaced the Coventry Climax as the standard F1 powerplant.

Lotus, McLaren, Matra, Brabham, March, Surtees, Tyrrell, Hesketh, Lola, Williams, Penske, Wolf and Ligier are just some of the teams to use the DFV, and 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 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 flat-12 engine configurations (most notably Ferrari) had enjoyed a handling advantage because of the low centre of gravity in such a configuration. However for ground effect, the wide-angle engine was completely the opposite of what was required: 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 0-754815-099</ref> Whilst BRM and Matra V12s were also available on similar customer terms to the DFV, and would also have been suited to ground effect aerodynamics, as Tyrrell's designer Derek Gardner explained, "...no-one wanted [the Matra engine] because all the horsepower went down the exhaust pipes, and no-one wanted a BRM engine for much the same reasons!"<ref> Hilton, Christopher (2002) Ken Tyrrell - Portrait of a Motor Racing Giant pp68-69 Haynes Publishing ISBN 1-85960-885-X</ref>

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. 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 0-754815-099</ref> Michele Alboreto took the DFV's last F1 win in a Tyrrell at Detroit in 1983, and Martin Brundle was the last person to race in F1 with a DFV, also in a Tyrrell at the Austrian Grand Prix in 1985.

[edit] F1 variants

The DFV had two major upgrades over its life, first with the DFW and then the DFY, last used in 1985. With the new 3.5 litre normally-aspirated formula running alongside the 1.5 litre turbos in 1987, an enlarged version known as the DFZ was introduced, powering Tyrrell, AGS, March, Lola and Coloni chassis that year. A separate constructors' award for the non-turbo runners, appropriately named after Jim Clark, was won by Tyrrell.

The DFZ proved the basis for the DFR, which was supplied to Benetton, Ford's exclusive works team in 1988 before the DFR became available to all customers in 1989, with the Benetton Team also using this engine until the introduction of the brand new HB at the French Grand Prix. The DFR struggled on until the 1991 season finally being eclipsed by the higher revving abilities of the new pneumatic valve gear engines such as the HB, and was last used in that year's Australian Grand Prix by the Footwork, Fondmetal, Larrousse and Coloni teams, nearly a quarter of a century after the DFV's first race...

[edit] Other formulae

The DFV's legendary success was by no means limited to Formula 1, with the engine being used in sportscar racing with some modest success. The design of the crankshaft caused vibrations that caused reliability problems in endurance racing. Seven years after it was introduced, the engine won the Le Mans 24 Hours twice, first in the Gulf-sponsored Mirage driven by Jacky Ickx and Derek Bell in 1975, then with the surprise winners Rondeau in 1980, driven by Jean Rondeau and Jean-Pierre Jaussaud.

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.

[edit] Stateside success with the DFX

A 2.65 litre turbocharged version of the DFV, known as the DFX, was produced in the late 1970s and went on to dominate American Indycar racing in much the same way the DFV had dominated Formula 1, winning the Indy 500 10 years running from 1978 to 1987, and winning all USAC and CART championships between 1977 and 1987.