The new XF Ford-Cosworth engine for the CART racing series.

"It's a more complete engine than anything we've done before," said Bruce Wood, CART Program Director for Cosworth Racing. The XF's 18% weight reduction is due in part to lighter castings with thinner walls achieved via a patented Cosworth casting process. The 32-valve, 8-cylinder, 2.65-L Ford-Cosworth XF is about 22 kg (50 lb) lighter than the XD engine it replaces. XD - used 1996 through 1999 - was capable of 15,000 rpms. The XF approaches 16,000 maximum rpms, produces more than 634 kW (850 bph), and more than 400 Nom (300 lboft) of torque. "The biggest step forward was more power. It's a double-digit gain," said Wood.

Computer finite element analysis (FEA) helped engineers determine which XD engine metal parts could survive and thrive with a different material make-up. "It was the first time we did use it (FEA) so extensively," said Wood.

Primary materials in the engine are cast aluminum (cylinder block - cast by Cosworth Castings), steel (crankshaft), and forged aluminum (pistons - forged and machined by Cosworth). Titanium and carbon are also used in engine components. "We basically machine almost everything on the engine, the exception being valves," Wood said.

The center of gravity for the XF is about 19 mm (0.75 in) lower than the XD's. The XF's narrow-angle V design permitted a smaller engine package and enhanced aerodynamics. Ancillary parts including the water heater tank and swirl pot (a device to air out cooling water) that were part of the chassis makeup on the XD are XF engine-integrated. Past Ford-Cosworth engines had a dual water radiator and oil cooler systems. The XF uses a single radiator and oil cooler system.

The XF engine also is 50 mm (2 in) shorter than the XD.

"If you took a cross-section of an engine, it really hasn't changed in 50 years," said Trevor Crisp, Managing Director of Cosworth Racing, a wholly owned subsidiary of Ford Automotive Holdings. "It's really when you get down to details that it represents a change."

Champ cars with the Ford-Cosworth XF engine include the #11 Big Kmart/Route 66 (Christian Fittipaldi), #6 Big Kmart, Texaco/Havoline (Michael Andretti), #8 Shell (Kenny Brack), #19 MTCI (Takuya Kurosawa), #7 Miller Lite (Max Papis), #32 Player's, Indeck (Patrick Carpentier), #40 Tecate, Quaker State (Adrian Fernandez), #20 Visteon (Roberto Moreno), and #33 Player's, Indeck (Alexandre Tagliani).

The follow-up engine to the XF is anticipated in three years.

Kami Buchholz

AEI September 2000
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