Ford-Cosworth Indy V8 engine

Ford-Cosworth Indy V-8[1][2]
Overview
Manufacturer	Ford-Cosworth
Production	1969, 1976–2007
Layout
Configuration	90° V-8
Displacement	2.65 L (162 cu in)
Cylinder bore	3.373 in (85.7 mm)
Piston stroke	2.256 in (57 mm)
Valvetrain	32-valve, DOHC, four-valves per cylinder
Compression ratio	11.2:1
Combustion
Turbocharger	Cosworth
Fuel system	Electronic fuel injection
Fuel type	Gasoline/Methanol
Oil system	Dry sump
Output
Power output	700–950 hp (522–708 kW)
Torque output	340–590 lb⋅ft (461–800 N⋅m)
Dimensions
Dry weight	120 kg (265 lb)[3]
Chronology
Predecessor	Ford Indy V8 engine

The Ford-Cosworth Indy V8 engine is a series of mechanically similar, turbocharged, 2.65-liter, Indy car racing V-8, designed and developed by Cosworth in partnership with Ford. It was produced for over 30 years. First, for use in the 1969 Indianapolis 500 by Team Lotus, and later, for the U.S.A.C. Championship Car, C.A.R.T., and later Champ Car World Series; between 1976 and 2007.^{[4][5][6][7][8][9][10][11][12][13][14][15]}

Lotus 64 engine[]

Because the previous 56 had a gas turbine engine, Lotus decided to build a new engine for the 1969 Indianapolis 500. The project was funded by Ford who supplied a V8 turbo engine, and by STP. The biggest difference was the new engine; a 2.65-liter turbocharged Ford engine, making more than 700 horsepower.^[16][17]

DFX[]

A 2.65-L turbocharged version of the DFV was developed privately by the Vels Parnelli Jones team for the 1976 U.S.A.C. season, in the face of opposition from Duckworth.^[18] The Parnelli-Cosworth car took its first victory at the 1976 Pocono 500, the fifth race of the season, driven by Al Unser.^[18] 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 wanted to establish the team as the North American distributor for the turbocharged, Indycar-specification engine.^[18] 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.^[18] Henceforth it became known as the DFX. It went on to dominate 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 U.S.A.C. and CART championships between 1977 and 1987 except for one. For a brief time in the early 1980s, some of the DFX engines were badged as Fords. 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 840 bhp (630 kW).

DFS[]

In 1986 GM financed the British Ilmor firm to build a competitor to the DFX in American Indy car racing. Mario Illien's 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" version of the Indy car engine which would be referred to as the "DFS" ("S" for short stroke).,^[19] 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,^[20] 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.

XB / XD / XF / XFE[]

Cosworth designed a series of replacements for the DFS to be used in IndyCar and Champ Car racing: the X-series, beginning in 1992 with the XB. The XF was developed for the 2000 season to replace the XD, and was chosen as the spec engine for the Champ Car World Series in 2003. The most recent derivative of the XF, the 2,650 cubic centimetres (161.7 cu in) XFE quad-cam 90° V8 overhead camshaft, continued in that role through the 2007 season.^[21][22] The Champ Car World Series imposed a rev limit of 12,000 rpm down from the over 15,000 rpm of 2002. The 2004 model of the XFE had a rated power of nominal 750 horsepower (559 kW; 760 PS) at 1,054 mmHg (intake boost pressure), and a maximum power of 800 bhp (597 kW; 811 PS) at 1130 mmHg (during Push-to-Pass). The 2004 XFE maximum speed was 12,000 rpm (rev limited) and torque of 490 N⋅m (361 lbf⋅ft). The aluminium and iron turbo housing ran a boost of 5.9 psi at sea level (= boost of 12 inches of mercury which is 41.5 inches of mercury absolute). The Methanol-fuelled engine used a steel crankshaft and aluminium alloy pistons. Weight was 120 kg (264.6 lb) and length was 539 mm (21.2 in).

In 2007, the Ford name was removed from the engine^[23] pieces as the manufacturer elected not to continue sponsorship of the series.^[23] Several other engine changes were made, notably the removal of the calibrated "pop-off valve" designed to limit turbo boost pressure, replaced by engine electronics. The rated life of the engine was 1,400 miles (2,300 km) between rebuilds. Engines were sent by the race teams to Cosworth for the rebuild. In 2007, Champ Car switched to the new Panoz DP01 chassis, which was said to provide better ducting of airflow into the engine. The Champ Car World Series merged into the Indy Racing League IndyCar Series prior to the 2008 season, and Cosworth does not currently provide engines to any American open-wheel racing series.

There is evidence that Cosworth was working on a 3,400 cc (207.5 cu in) push-rod V8 along the lines of the Ilmor/Mercedes 500I to exploit the peculiar loophole in the Indianapolis 500 rules on the definition of the word "pushrod engine", permitting such engines with extremely short pushrods higher turbocharger boost – this was assigned a project code CD but seemingly never completed.

In mid-2003, Cosworth provided the 3.5 L V8 XG badged as a Chevrolet Gen 4 engine to IRL IndyCar Series teams after the proprietary Chevrolet Gen 3 engine proved inadequate against rival Hondas and Toyotas during the 2003 season. While many teams left Chevrolet after the 2003 season, those that stayed saw a significant improvement in performance with the new "Chevworth" engine compared to their previous units. The XG finished second in its first race at Michigan on July 27, 2003. Sam Hornish, Jr. went on to win 3 races that season with the new XG. The XG was reduced in size to 3 L for the 2004 season and it won one race in 2005 during Chevrolet's final season in IRL.

References[]