The brilliant DOHC four valve Peugeot begat the exquisite Millers and the mighty Offenhauser that reigned at Indy from 1935 finally surrendering its crown after its 28th “500” victory in 1976. Across three decades -- 1931 through 1952 -- Diesel power, as epitomized by the 1934 Cummins 2-stroke Diesel defied and defeated not only Indy convention but draconian fuel consumption rules in 1934. Cummins Diesel power went on to claim Indy’s coveted pole position in 1952.
By then the “500” had changed speed, shape and style through the Miller front wheel drive era of the 1920s through 1949, the birth of the Roadster in 1952, the rear engine invasion of the 1960s with the introduction of Formula 1 technology and the arrival of Formula 1 World Champions Cooper and Lotus. Ground effects arrived at Indy from Formula 1 in 1979 and, as in 1961, everything changed with speeds climbing steeply.
Some innovations came too far too fast turning Indy’s engineering and design orthodoxy inside out. Turbine engines twice came close to Indy’s victory lane, none with more engineering flair than the Lotus four-wheel-drive Type 56 that, in 1968, retired from the lead less than 23 miles from the richest payday in motorsport. A year after Jim Hall’s Chaparral 2K became the first Indy 500 ground effects winner Dan Gurney’s radical stock-block Chevy V-8 Eagle BLAT -- Boundary Layer Adhesion Technology -- blew established ground effects doctrine apart, started from the front row of the “500” with a stock-block Chevy V-8 engine and a week later won the Milwaukee 150-miler from that last row. It was promptly legislated out of existence.