Innovation a hallmark of cars at Indianapolis 500

INDIANAPOLIS (AP) With the 100th running of the Indianapolis 500 set for May 29, The Associated Press looks at cars that have changed the race over the years. The list is completely subjective:

MARMON WASP

It all started with this car. Most people know Ray Harroun as the first winner of the Indianapolis 500. What they don't know is that the engineer designed the winning car, too. The yellow-and-black car had a smooth cockpit, a pointed tail and a six-cylinder engine. Instead of using a riding mechanic, which most drivers did to keep track of traffic behind them, Harroun introduced the rear-view mirror. The result: Harroun finished the first race in 6 hours, 42 minutes, 8 seconds, more than 100 seconds ahead of runner-up finisher Ralph Mulford, a win that changed racing and solidified Indy's reputation for innovation.

NOVI SPECIAL

Was it the greatest race car never to win at Indy? Perhaps. Ed and Bud Winfield, makers of racing carburetors, first brought the Novi engine to the track in 1935. Then came the turbo-charged, 3.0-liter engine, which debuted at the 1941 race. In 1961, after two decades of trying to win at Indy, Novi's assets were sold to Andy Granatelli, who only added to the engine-manufacturer's reputation for creativity. The chase for victory lane officially ended in 1966 when the Novi-powered cars failed to qualify for the 33-car starting grid. They also did not finish the races in 1964 or 1965.

THE OFFY

Fred Offenhauser designed an engine that won three 500 titles before World War II and didn't lose a thing when it returned to the speedway following the hiatus from 1942-45. In fact, Offenhauser-powered cars got even more popular after the war. They dominated the post-war lineup, claiming all 33 starting positions in 1954, 1955, 1959 and 1960, and won an additional 24 races at Indianapolis following WWII. And perhaps most incredibly, the engine won 18 consecutive races at the Brickyard, taking every race title from 1947-64 - a record that may never be challenged.

GOING BACKWARD

In 1959, Duane Carter turned Indy upside down. Or perhaps inside out. The man who drove the ''Smokey's Reverse Torque Special'' made the most of his car owner's strange ploy. Smokey Yunick decided to challenge racing norms by turning around the popular Offy engine and running it, yes, backward. Carter didn't do badly. He qualified 12th for the race and finished seventh, the top finisher of anyone running their engine clockwise. The gamble actually was a precursor to perhaps the most innovative decade in race history, the 1960s.

KIMBERLY COOPER-CLIMAX

Australia's Jack Brabham wound up changing IndyCar racing. The Indy 500 rookie came to the track in 1961 with a car that followed the European trend of placing the engine in the rear of the car. Brabham qualified 13th and finished ninth. In 1962, more drivers were using the rear engine. By 1965, 27 of the 33 starters had converted and Scotland's Jim Clark became the first Indianapolis 500 winner with a rear-powered engine. Nobody has qualified for the race in anything other than a rear-engine powered car since 1968.

MISTER 500

Andy Granatelli never met an innovation he didn't like. He brought super-charged engines to the speedway in the early 1960s. When they didn't win, he kept changing the plan. In 1969, he introduced a four-wheel drive Ford engine. He finally won his first 500 when Mario Andretti drove a conventional engine in his backup car. But the late ''Mister 500'' might be best remembered for bringing turbine-powered engines to the speedway in 1967 and 1968. Those cars, which had 80 percent fewer parts than traditional engines, became fan favorites and were leading both races before mechanical failures knocked them out of the race.

MERCEDES MASH

Roger Penske may have changed the way IndyCar teams conduct business. In 1994, Penske's team couldn't be touched. He came to Indianapolis with a roughly 1,000 horsepower engine built by Mercedes for only one race, the 500. The pushrod 500I Ilmor V8 dominated the month. Al Unser Jr. won the pole and his second Indy crown. Two-time 500 winner Emerson Fittipaldi led the most laps (145) on race day before crashing on lap 185. A crash in practice forced Paul Tracy to start from the back of the field and he was further sabotaged with a mechanical failure after completing just 92 laps.