table on a future engine, he threw the thought of a diesel into the melting pot. After all, at that stage Audi was targeting the American market by running the diesel R10 in American Le Mans Series races. It was, perhaps understandably, never going to happen and Baretzky was more serious in suggesting an in-line four petrol engine. However, there was precedence. On the first day of time trials for the 1952 Indianapolis 500, Freddie Agabashian drove his Cummins Diesel Special onto the 2.5-mile oval. After two quick warm-up circuits, he took the green flag that signified the start of his four-lap qualifying run. On his first lap he recorded an impressive 139mph that onlookers could hardly believe. The next three laps were not much slower and, with chunks of rubber tearing off a rear tyre, his final average was 138.010mph – a new track record. As a result, a diesel- engined car sat on pole position for the 1952 Indianapolis 500.
A
Uncommon engineering
Between 1931 and 1952, Cummins diesel-powered racecars stormed The Brickyard, yet no compression ignition engine has raced there since…
BY IAN WAGSTAFF
CUMMINS A-COMING The idea of entering a diesel car for the Indy 500 dates back to 1931. Stock engines were being encouraged to cut costs, and perhaps the most outstanding entry of all was the enormous Duesenberg entered by Columbus, Indiana-based Cummins. It was the first diesel to race at ‘The Brickyard’, having just set a 101mph record on Daytona Beach. Cummins founder, Clessie Cummins, who had been on 1911 500 winner, Ray Harroun’s, pit crew, had commissioned August Duesenberg to build the car from one of his Model A passenger car chassis. At 3389lb (1537kg) it was the second heaviest car on the grid that year. Powering the car was an 85bhp,
slow-speed, four-cylinder, four- valves-per-cylinder, 361.5ci marine engine, described as ‘semi-stock’, due to its cast iron pistons having been replaced by aluminium ones. (Four-valves-per-cylinder had been included in the regulations for the 1931 Indy 500 in an attempt to attract European entries but none took the bait.)
When Cummins first discussed the ides of a diesel entry with
May 2012 •
www.racecar-engineering.com 25
udi’s motorsport engine guru, Ulrich Baretzky, admits that, when the then IndyCar League convened its round
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100