IRL: Las Vegas Oldsmobile Engine Notes

* THE 700-HORSEPOWER CEREAL BOX. The IRL's engine rules stipulate a maximum displacement of 4.0 liters. For the metrically challenged, that's 244 cubic inches - a volume about the size of a 23-ounce box of shredded wheat breakfast cereal. ...

* THE 700-HORSEPOWER CEREAL BOX. The IRL's engine rules stipulate a maximum displacement of 4.0 liters. For the metrically challenged, that's 244 cubic inches - a volume about the size of a 23-ounce box of shredded wheat breakfast cereal.

An IRL Aurora V8's pistons are 93 millimeters in diameter - a little larger than a can of tuna fish.

* MILE-A-MINUTE PISTONS. The pistons in an IRL Aurora V8 engine travel less than 6 inches in their cylinders with every crankshaft revolution, but those inches add up fast when the crank is spinning at 10,500 revolutions per minute. Each piston travels 5,061 feet in one minute - nearly a mile up and down in the cylinder. In a 25-second lap around Las Vegas Motor Speedway, the pistons travel 1.5 miles around the track and four tenths of a mile up and down in their cylinders.

When the pistons change direction at the top of the bore, they are subjected to a maximum acceleration of 70,000 times the force of gravity.

* DEEP BREATHING. At 10,500 rpm, an IRL Aurora V8 consumes almost 1,000 cubic feet of air in one minute - a volume equivalent to the air inside an average bedroom.

* THE CHAIN GANG. Like the production Aurora V8, the racing version uses chains to drive its dual overhead camshafts. At maximum rpm, these chains travel at nearly 60 mph around their sprockets.

* ENGINE ECONOMICS. The price of an IRL Aurora V8 racing engine from Oldsmobile's designated engine builders is $80,000. For comparison, the Manufacturers Suggested Retail Price for a 1998 Aurora sedan is $36,825 - which includes the 4.0-liter Aurora V8 production engine that inspired the racing version.

* FAST ACTION. Things happen fast inside an engine running at 10,500 rpm. At maximum speed, the crankshaft in an IRL Aurora V8 rotates 175 times per second, and its spark plugs fire 700 times per second.

* THE AIR FORCE. Although the IRL's 4.0-liter engines are naturally aspirated, they get a performance boost from the forward-facing air scoops behind the drivers' heads. At racing speeds, the scoop produces enough positive pressure to increase the engine's output by 5 percent - approximately 35 horsepower.

* LEADER OF THE PACK. Oldsmobile engines led 3,481 consecutive laps before the rival Infiniti Indy led a lap at an IRL event. Oldsmobile racers have completed 77,695 racing miles - a distance equal to three laps around the Earth's equator!

* IRL - NASCAR COMPARISON. The open-wheeled single-seaters that compete in the Pep Boys Indy Racing League are a dramatic departure from the full-bodied Winston Cup stock cars that raced at Las Vegas Motor Speedway earlier this year.

A typical IRL Aurora V8 engine produces over 700 horsepower - about the same power as a Winston Cup engine - but does it with one-third less displacement. A 4.0-liter IRL Aurora V8 displaces 244 cubic inches, while a Winston Cup small-block displaces 358 cubic inches.

The IRL Aurora V8 engine makes up for its smaller size by revving higher (10,500 rpm vs. 8,800 rpm), burning methanol fuel instead of gasoline, and operating at higher efficiency. Like its production counterpart, the IRL Aurora V8 has 32 valves-twice as many as a Winston Cup small-block-and four camshafts (instead of the single cam used in a NASCAR engine).

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Series IndyCar