| Ilmor-Chevrolet 265-A[1][2][3] Ilmor-Chevrolet 265-B[4] Ilmor-Chevrolet 265-C | |
|---|---|
 | |
| Overview | |
| Manufacturer | Ilmor |
| Production | 1986–1993 |
| Layout | |
| Configuration | 80°-90°V-8 |
| Displacement | 2.65 L (162 cu in) |
| Cylinder bore | 3.465 in (88.0 mm) |
| Piston stroke | 2.142 in (54.4 mm) |
| Valvetrain | 32-valve,DOHC, four-valves per cylinder |
| Compression ratio | 11:1 |
| Combustion | |
| Turbocharger | Holset |
| Fuel system | Mechanical multi-point fuel injection |
| Fuel type | Methanol |
| Oil system | Dry sump |
| Output | |
| Power output | 720–850 hp (537–634 kW) |
| Torque output | 350–510 lb⋅ft (475–691 N⋅m)[5] |
| Chronology | |
| Successor | Ilmor Mercedes-Benz 265-D (1994) |
TheIlmor 265-A is aturbocharged, 2.65 L (162 cu in),V-8Indy car racingengine, designed and developed byIlmor, for use in theCART PPG Indy Car World Series; between 1986 and 1993.
Mario Illien andPaul Morgan were working at Cosworth on theCosworth DFX turbocharged methanol engine for theCART Indy Car Series; differences of opinion over the direction in which DFX development should go (Cosworth were inherently conservative as they had a near monopoly) led them to break away from their parent company to pursue their own ideas. There was some acrimony in their split from Cosworth, their former employer claiming that the Ilmor engine was little different from their planned modifications to the DFX.[6]
Founded as an independent British engine manufacturer in 1983, Ilmor started building engines forIndy cars with financial backing from team owner and chassis manufacturerRoger Penske. The Ilmor 265-A, badged initially as the Ilmor-Chevy Indy V-8, debuted in1986. The engine was used part-time by Penske team drivers, withAl Unser Sr. racing it at the1986 Indianapolis 500. Mears notched two poles and two 3rd place finishes with the engine late in the season.
In 1987, the 265-A engine program expanded to full time atPenske Racing. Penske's primary driversRick Mears andDanny Sullivan raced it full-time. A third car was entered at Indianapolis forDanny Ongais. However, Ongais was injured in a crash during practice. He was replaced byAl Unser Sr. (who instead fielded a Cosworth). The 265-A was also fielded byNewman/Haas Racing (Mario Andretti) and atPatrick Racing (Emerson Fittipaldi andKevin Cogan). Andretti won atLong Beach, the engine's first Indy car victory. He also won the pole position for the1987 Indianapolis 500.
With the 265-A engine now badged as the Chevrolet Indy V-8,Rick Mears won the1988 Indianapolis 500, the engine's first win at Indianapolis. The engine went on to have a stellar record inCART. From 1987 to 1991, the "Chevy-A" engine won 64 of 78 races including the Indy 500 from 1988 to 1991.
In1992, the 265-B engine was introduced. The "Chevy-B" was fielded singly by Penske Racing (Rick Mears andEmerson Fittipaldi) in 1992 and won four CART series races. All other Ilmor teams remained with the venerable 265-A for 1992.Bobby Rahal, driving a "Chevy-A" won the 1992 CART championship, the fifth consecutive (and final) for the 265-A.Al Unser Jr. won the1992 Indianapolis 500 driving a "Chevy-A", also the fifth consecutive (and final) Indy 500 win for the 265-A.Emerson Fittipaldi drove a "Chevy-B" to 4th place in points, but both he and Mears dropped out of that year's Indy 500 due to crashes.
It was at this time that Ilmor was receiving new competition fromCosworth, which had just introduced their new powerplant, theFord-Cosworth XB.
For the1993 season, the 265-C engine was introduced, intended to replace both the 265-A and the 265-B. The "Chevy-C" was used widespread, and produced continued success for Ilmor. Some backmarker teams continued to utilize the 265-A and 265-B engines during the 1993 season, but neither the "A" nor the "B" would win another Indy car race. Chevrolet dropped its badging support after the 1993 season.
In 1994, Ilmor introduced two new engines, the265-D and the265-E. The "D" would later be badged as the "IlmorMercedes-Benz D". The "E" was actually a top-secret 209 in3 (3.42 L) purpose-built, V-8pushrod engine developed forTeam Penske for the1994 Indianapolis 500. While most Ilmor teams upgraded to the "D", the "C" and a variant called the "C+" saw some limited use during the 1994 season.