In 1926 AAA introduced new regulations that limited engine size to just 91 in³ (1.5 liters) to slow the cars. Harry Miller, an American race car designer and builder, who build single-seater race cars and engines since 1919, had to create a new engine for his new cars and his existing customers. To make up the lack of displacement, Miller and his team fitted a centrifugal supercharger. Some of the very first blown Millers appeared in 1925, on the 122 in³ engines. By the time the 91 in³ formula was set, Miller could already produce more power from the smaller displacement. With nearly 250 bhp on tap, the 91 could top out 171 mph. Miller produced both a rear-wheel drive (RWD) and front-wheel drive (FWD) version of the 91. At least 10 FWD and at least nine RWD cars were built. Millers 91 dominated the AAA races and filled most of the Indianapolis field from 1926 to 1929, winning the 500-miler in 1926, 1928 and 1929.
The 1926 winner rookie Frank Lockhart, a little known 23-years old dirt car racer from California, becomes a Cinderella story. He arrived at Indy as a relief driver for Peter Kreis, who became ill and withdraws. Lockhart in his first paved oval race recorded one-lap qualifying record of 115.488 mph, but shred the tire before he completes the required four laps. He finally started 20th, went to the lead on lap 60, led 96 laps, and won the race which was stopped after 160 laps due to rain. Later the season Lockhart bought the Miller 91 car and won four more races of the AAA National Championship, and finished second in the standings.
In 1927 Lockhart qualified on the pole for the Indianapolis 500 in his Perfect Circle Miller. He led the opening 81 laps before his car broke a connecting rod, setting an opening lap-leader record that stood for 64 years. He won four more AAA championship events in 1927, and repeated the vice-championship. The racing career and life of the young talented driver ended in a fatal accident in land speed record run at Daytona Beach. On April 25, 1928 Lockhart’s Stutz Black Hawk Special streamliner went out of control and tumbled violently across the sand, throwing Lockhart from the car and killing him instantly.
The scale models of 1926, 1928 and 1929 Indy 500 winning Millers were made by Replicarz in a limited edition series.
|1926||AAA National Championship||Indianapolis 500|
|Frank Lockhart||15||Peter Kreis|