Fascinating story of the development and racing of the Cummins diesel race car at the Indianapolis 500 in 1952. Number 28, the Cummins Diesel Special, clocked a qualifying track record that year of 138.01 MPH, using a truck type Cummins diesel engine. What a story! Transferred from a 16mm Eastman Color film, with significant color fade.
In 2017 number 28 appeared at the Goodwood Festival of Speed
It’s the perfect ecosystem-come-melting-pot, therefore, for something like the Kurtis-Kraft Cummins Diesel Special to sprout. The ‘50s had to be one of the most developmentally lucrative periods in the history of motorsport. The world was shaken, battered and bruised by war, determined to forge better lives for all and blossoming economically as international trade exploded. The pot of cash and hunger for growth that was the bow-wave of post-war recovery swept all industries and with innovative products being produced in unprecedented numbers that needed to be sold, concepts needed to be proven. Where else other than the racetrack does automotive technology prove its chops?
Technical challenges forced innovation. The high centre of gravity that was the 1950 car’s Achilles heel meant that the Cummins 6.6-litre commercial engine had to be laid on its side – the happy side-effect of which was a left-hand weight bias for the left-turn-only machine. It was the first car to race at Indy to feature an exhaust-fed turbocharger, as well as the first car to be tested in a wind tunnel. Driver-activated radiator shutters were developed such that a boost of 18 horsepower could be accrued with their operation. The newly developed layout made it the lowest car on the grid, too. The car was heavy (in spite of a lightweight alloy block) but it was slippery and very powerful with the monstrous lump good for over 400bhp. Cummins had proven the advantages of diesel at Indy before in 1931 when a car went for the full 500 laps without a pit stop. They would move to avenge their fateful 1950 attempt in ‘52 with the game-changing new car.
Don Cummins had designs on San Francisco’s 32-year-old race ace Freddie Agabashian to pilot but it was a difficult sell. When approached, Freddie was sceptical of the car’s weight and overall competitiveness. On a drive out around Indy with Freddie, Don had a point to prove. He stopped the car, pulled a 5-inch Coca Cola crate out of the boot and set it on the ground outside the car upside down. He gestured for Freddie to sit, following “That’s all the farther you’ll be riding above the pavement in a new roadster”. Convinced of the innovations the new car would bring to the fight, Freddie was sold