Roger Rager, a sprint car ace best known for leading the Indianapolis 500 in a car powered by a stock block engine that had started out in a school bus, has died at the age of 73.

A native of Nebraska, Rager scored numerous victories in sprint cars and was the only driver to win at renowned Knoxville Raceway in each decade from the 1960s to the 2000s. He made his IndyCar debut in 1976, and qualified for the Indy 500 in 1980 after a couple of near-misses with his low-budget team.

Rager was a popular David-vs-Goliath story that year, as he drove a three-year-old Wildcat (pictured above) powered by a Chevy stock block engine that Rager had removed from a school bus in a junkyard, at a time when Cosworth race engines ruled the Speedway. He qualified 10th, ahead of A.J. Foyt, Gordon Johncock and Tom Sneva, and even led two laps of the race before being collected by another driver’s spin. Rager gained some consolation by being named Rookie of the Year by USAC.

Rager later returned to sprint car racing, while also building an RV resort business, Rager’s Acres, in Pequot Lakes, Minnesota. He was a Masters Champion three times in six years at Knoxville and was inducted into that iconic track’s inducted Hall of Fame in 1990.