The so-called ‘junk formula’ began in 1930 as a way of luring automobile manufacturers back to the Speedway. The domination of Duesenberg and Miller had virtually driven manufacturers from the 500-mile race, and starting fields from 1920 to 1926 totaled as few as 22 cars. Eddie Rickenbacker led development of the new rules that—most importantly—increased engine size from 91 cu. in. of the supercharged Miller and Duesenberg thoroughbreds to 366 cu. in., and eliminated the use of supercharging. Development of the new rules was ongoing throughout 1928 and the rules were approved for the 1930 racing season.
It was the response to the new rules, not the intent, that gave the formula its disparaging name. Manufacturers Studebaker and Ford designed and built teams of cars for the new rules. Cummins built a well-engineered racer that placed a Cummins diesel engine in a Duesenberg chassis and finished the 1931 500-mile race without a single stop. A larger number of ‘specials’, however, were finished to widely differing levels of specification utilizing production chassis or engines.
Miller-powered cars continued their winning way with seven more victories between 1930-1938; two more 500s were won by engines created by former Miller draftsman Fred Offenhauser. The dominance was so complete that 28 of the 33 starters in the 1936 500 were behind Miller or Offy powerplants. Louie Meyer became the first three-time 500 winner in the same race.
The intended benefit of the new rules was to spur production-based entries. A large variety of engines were raced at the Speedway in the 1930s including Studebaker, Ford, Hudson, Reo, Chrysler, Buick, Hupmobile, Graham, Packard and others. These engines found their way into an equally varied number of chassis. More and more, however, Speedway cars were associated with the name of the mechanic who created or maintained them rather than with the names of manufacturers in earlier times.
Auto racing sponsorship also appeared during this time. While teams were previously associated with the names of manufacturers, by the mid-1930s the majority began to be identified with sponsors. Wonder Bread, Stokley’s Foods and Barbasol shaving cream were among early Indianapolis 500 sponsors, along with oil companies and other auto-related products. Similar sponsorship didn’t come into Formula 1 before the late 1960s.
In spite of the fact that the rules introduced in 1930 did not bring about the desired re-entry of automobile manufacturers to the Speedway, the rules did foster innovation. In addition to entries powered by diesel (Cummins), driven by front-wheel drive (Miller-Ford) or all-wheel drive (Four Wheel Drive Auto Company), other advances included aerodynamics, engine placement and engine configuration.
Harry Miller’s last creation for the Speedway was a tour de force, although it was never successful. The project began with funding from Gulf Oil Company. Miller created three highly sophisticated rear-engine, supercharged six-cylinder racers with four-wheel drive. The concept and workmanship were brilliant and predicted several successful Speedway designs by decades but the cars were never fully developed. One car qualified in 1939, and two in 1941. One car raced again in 1946 and 1947 entered as the Preston Tucker Special.
A further result of the rules was to see a return of European entries to the 500-mile race. These were no longer the manufacturers’ teams of earlier times, but privately entered cars that were often underperforming grand prix cars in the face of the 1930s GP dominance by the German Silver Arrows teams. Alfa Romeos entered in 1937 and 1938 led to Wilbur Shaw’s success with an Maserati 8CTF with which he won the 1939 and 1940 races handily and was leading the 1941 race before a wheel broke, costing Shaw a record third-straight 500 victory.
A New Dawn
In what is still only the second sale in the track’s history—now more than 100 years—ownership of the Speedway passed into the hands of Terre Haute, Indiana businessman Anton ‘Tony’ Hulman in late 1945. Preparations began immediately to restore the Speedway from four years of wartime neglect in time to stage a 500-mile race in May 1946. The Indianapolis Motor Speedway once more presented a metaphor for a world starting over. Rebuilding began in earnest and continued right up to race day. Once undergrowth that claimed the track and infield was cleared away and rotting infrastructure had been torn down, participants and fans were astonished to see the progress made in little more than six months. And the Speedway welcomed a rush of European refugees.
A total of 56 entries poured in for the renewed Memorial Day classic. Among them were a number of pre-war grand prix machines and drivers, some that had found themselves in the U.S. when fighting broke out in Europe in 1939. Tazio Nuvolari and Luigi Villoresi were entered in a pair of Maseratis. Rudi Carracciola was entered in one of the 1.5-liter Mercedes 165s built for the pre-war Tripoli GP. Achille Varzi was nominated to drive another Maserati, while Harry O’Reilly Schell entered three Maseratis and an Alfa Romeo. Zora Arkus-Duntov, who worked in New York throughout the war, was entered with a Talbot.
Of these only Villoresi qualified, although another seven Maseratis and Alfa Romeos qualified for the 1946 Indianapolis 500 driven by American drivers.
But it was clear from the first day of 1946 qualifications that the balance of power had shifted across the Atlantic. While Mauri Rose sat on the pole for the 1941 500 in a Maserati, the 1946 pole sitter was Ralph Hepburn with a supercharged American Novi V-8 in a front-drive (fwd) chassis built by Californian Frank Kurtis. Hepburn’s qualifying speed broke the Speedway track record by nearly four miles per hour, after a layoff of five years!
The next period in Indianapolis 500 history would last twenty years and would be characterized by an era American ingenuity, bravery and record-breaking speeds.
The Offy Roadsters
Frank Kurtis was one of a number of enormously talented fabricators who learned their craft in Southern California. Kurtis was already building successful midget racing cars when he got his first taste of the Indianapolis 500 in 1939. In the years immediately following WWII, Frank Kurtis changed the history of the Indianapolis 500.
The proliferation of new chassis designs fostered by the 1930 rules came from a wide range of individual thought. Frank Kurtis changed that almost single-handedly, and ushered in the era of the Indy Roadster.
The Ross Page Kurtis first raced at the Speedway in 1946 has been called “the proto roadster” by historian Mark Dees. The chassis was built from high-strength aircraft-quality tubing in place of earlier channel-section frames. Other Kurtis ideas, including an offset driveline that allowed the driver to be seated lower in the car, also improved the car’s handling. Kurtis designed and constructed a similar chassis for the 1946 track record-breaking Novi driven by Ralph Hepburn. The car Kurtis built for car owner Howard Keck and that was driven by Bill Vukovich beginning in 1952 is acknowledged as the first Indianapolis-type Roadster, incorporating all of the elements of the design.
Other highly original designs were also created in the early post-war years. The Fageol Twin Coach Special powered by two Offy midget engines—front and rear—was the second fastest qualifier in 1946. The fwd Blue Crown Specials built by Emil Deidt became the first team in Indianapolis 500 history to win three consecutive races in 1947-1949, and carried Mauri Rose to his record-tying 3rd Indianapolis 500 victory in 1948. But none equaled the elan of the rear-engine Rounds Rocket from 1949, one of the most beautifully finished cars ever not to qualify at the Speedway.
Kurtis chassis were built in series production, and in short order Kurtis cars dominated Indianapolis 500 starting lineups like no one had done in decades. Two Kurtis chassis started the 1946 race. Kurtis cars won six-straight 500s from 1950 to 1955 and 23 Kurtis cars started the 1956 500, but their influence was even greater. Talented mechanics like A.J. Watson, George Silah, Ernie Trevis and George Bignotti adapted their own ideas to Kurtis’ innovation. Roadsters built by these men and others won every Indianapolis 500 through 1964.
The first 4-time Indianapolis 500 winner A.J. Foyt won his first two Speedway victories in Roadsters, including the 1964 race that was the last Indianapolis 500 to be won by a Roadster.
Engine choices in this era were equally narrowly focused. The four-cylinder dohc engine originally designed by Harry Miller and later refined by Fred Offenhauser was the only sure thing. An ‘Offy’ won for the first time in 1935, and again in 1937 and 1941. Beginning in 1947, the Offenhauser engine powered every Indianapolis 500-winning car for 18 consecutive years prior to 1965.