 Hartz bought a used 1927 Miller 91 front-drive race car, and built the car for the junk-formula by widening the chassis and installing a bored-out Miller 122 (151 cu in).Together with Billy Arnold as driver, the combination was successful, and they won the 1930 Indy 500 race and also took the national championship for the year.Hartz appeared in the racing sequences for the 1932 movie "The Crowd Roars".