The weird and wonderful cars of the ‘500,’ part 4

Published On April 19, 2016 » 11480 Views» By Marshall Pruett » Blogs, IMS, IMS History, Indy 500

We’re chronicling 100 days of Indy 500 history on #SpeedRead leading up to the historic 100th Running. With 40 days to go, racing journalist Marshall Pruett continues his look back at milestone cars and technology.

More Pruett: Weird and wonderful cars: Part 1Part 2, Part 3 The mighty “Offy” | Penske’s ’94 dominator | The “Fantastic” Turbine | Murphy’s Miller straight-8 | Yunick’s winged Watson More 100 days

We have fallen in love with the Indianapolis 500’s most accomplished designs since the Marmon Wasp won the first race in 1911. Since then, countless favorites have graced Victory Circle—Millers, Kurtis Krafts, Eagles, Penskes—and dozens of other race-winning cars or inspiring machines have enriched the great race.

And then, as history has recorded, we have the cars that reached too far or, in some cases, not far enough in pursuit of glory at the Indy 500. They stand as the weird and the wonderful, and some represent interesting footnotes—or origins—in chassis and engine design.

In Part 1Part 2 and Part 3 of this series, we’ve enjoyed looking back at cars that aren’t household names, yet have become beloved entries in Indy’s technological march to May’s 100th 500. We hope you enjoy Part 4.






Ignoring the fact that All American Racers’ Eagle chassis was an Indy 500-winning mainstay, Idaho’s Eagle Aviation took the Speedway’s Month of May challenge in 1982 with its curiously-named Eagle chassis.

Taking a page from the Department of Redundancy Department, the Eagle Aviation Eagle-Chevy was created by the company’s lead airplane designer, Dean Wilson.

Wilson, as you might have figured out by now, had zero experience in race car design. Driven by Ken Hamilton (father of IndyCar driver-turned-team-owner Davey Hamilton), the Eagle was an affront to the eyes and an abomination on the 2.5-mile IMS oval.

Before we get to the car’s mystifying aerodynamics, it’s worth pondering the retro chassis construction methods Wilson employed. Built at Eagle Aviation’s base in Boise, the Eagle Indy car used a throwback chassis made from welded tubes, blissfully ignoring the day’s standard of shaping and riveting lightweight aluminum-honeycomb panels into a thin “tub.” The Eagle, as far as I know, might be the last tubeframe Indy car ever produced. And the wackiness didn’t stop there.

The pieces we would call rear endplates were, just like some of the components on the small single-engine airplanes Wilson designed, made from wood. Oddly enough, although Wilson refused to use his airplane experience to create and attach wings to the car, he wasn’t afraid to use balsa and plywood to form some of the Eagle’s rear bodywork and aerodynamic profiles.

If anything, this bizarre chassis might have actually inspired famed Ferrari and Benetton Formula 1 designer Rory Byrne. The young South African broke from tradition in his early days as an F1 designer with the tiny Toleman team—long before he was penning cars that propelled Michael Schumacher to umpteen F1 titles—and his TG183 chassis from 1983.

Byrne’s TG183, and the TG183B, which was also used early in the 1984 season by F1 rookie Ayrton Senna, featured a front-wing assembly that had—and I’m not making this up—radiators sandwiched between the top and bottom wing profiles. The middle of the TG183/B’s front wings were used to cool the engine, just as Wilson did two years earlier with his 1981 Eagle.

The Eagle, with its naturally-aspirated 355 cu. in. stock-block Chevy V8, made great power, and for those who recall, similar V8-powered Indy cars from the real (AAR) Eagle team were fast and competitive at Indy. What separated AAR’s 1981 Eagle from Eagle Aviation’s 1982 Eagle was a basic understanding of ground-based aerodynamics.

Hamilton held his own on the straights in the Eagle during practice for the 1982 race, but Wilson’s unproven aero made cornering more a death-defying act than an exercise on road-holding ability. The Eagle’s dire lack of downforce meant the chassis wiggled, twitched, and slid through the corners as Hamilton held on for dear life.

With a wheelbase of 118 inches, the Eagle was, believe it or not, within the 117-122 inch range permitted with today’s Dallara DW12, but with Hamilton shifted so far forward—his toes were inches away from the nose—and so little bodywork between the wheels, the car looks much longer than normal … provided the word “normal” belongs anywhere near this car.

The arrogant Wilson, who assured Hamilton his brand-new aerodynamic concepts and appendages would revolutionize the Indy 500, churned out a car that was almost 12 mph off the slowest qualifying speed in 1982. In fact, drop the “9” from 1982, and that’s about the best the car would average around IMS. The pole for the 1982 race was 207 mph, for what it’s worth.

Tired of Wilson’s defiant and dismissive approach to the aerodynamic norms of the Indy 500, Hamilton paid $1,000 to have a rear wing made for the Eagle, and while it helped to settle the car’s nervousness at the rear, there was no hope of find the rest of the missing speed to make the show.

Hamilton spun the car twice and never touched the walls, which we can assume was a first and second reminder from above this Eagle chassis did not belong in the field of 33. And with the advent of the Internet, Idaho’s Eagle has gained newfound fame as an on-line favorite—a celebrated four-wheeled freakshow.

Is this the strangest car to lap the Speedway since the first Indy 500 was held in 1911? The answer is a matter of personal opinion, but if it isn’t No. 1 on your list, I’d love to know which car moved it down to No. 2.



Alden Sampson II decided a single 1.5-liter (91 cu. in) Miller straight-eight engine wasn’t enough for his driver Louis Meyer, so he fitted two Millers side by side for the 1930 race! The engine bay of the rear-drive Stevens chassis was packed full of componentry to make the odd V16 (it was really a double-eight) work in unison.

With a common crankcase devised to receive the power from the combined 201 cu. in of displacement from the Millers, the horsepower was sent to the back of the car through a single driveshaft.

Three cheers for Sampson’s adventurous spirit; Meyer qualified the heavy (but powerful) machine second and finished fourth on its debut.





1981’s Interscope chassis, piloted by the Flyin’ Hawaiian Danny Ongais, looks like a low-drag alien headed for a blast down the 3-mile-long Mulsanne Straight in Le Mans. It’s as sleek as it is strange, and if that wasn’t enough, try pronouncing the last name of the its designer, Roman Slobodynskj.

The Cosworth DFX turbo V8-powered car followed Slobodynskj’s 1980 Interscope-Porsche project (BELOW) for Marshall’s department stores heir and racer Ted Field. (In an unrelated nod to the Interscope name, artists ranging from the Notorious B.I.G. to Guns-n-Roses to New Kids on the Block to Elton John helped Field’s Interscope Record company and its affiliated labels to make untold millions starting in the late 1980s.)

Chaparral’s Formula 1-inspired ground effects 2K chassis was a wakeup call for the rest of the Indy 500 grid, and with the 1981 Interscope, all of the 2K’s tricks—and some new ideas—were employed.

Slobodynskj went for a longtail design to maximize the length of the underbody tunnels, and with that length, a more gradual wing profile became possible, which reduced the poor-handling phenomenon known as “pitch sensitivity.”

Take a look at the Interscope’s sidepods from its qualifying photo and you’ll notice something else that was unique for 1981—and has become the norm today—as Slobodynskj built tall, tapered rear tire ramps to smooth airflow around the big and wide slicks.

At the front of the car, more novel concepts were employed. The front upper rocker arms were completely enclosed with aerodynamic fairings, and the relatively small front wings—keep in mind the underwings made most of the necessary downforce so big wings weren’t required—sat outboard of smaller wing profiles that produced cleaner airflow to the underwing as it passed over the nose.

Unlike many of the radical-looking cars we’ve documented through the first three installments, the Interscope-Cosworth was fast. It took a year of development to extract its potential, and on its return in 1982, Ongais qualified ninth and ran well but suffered a terrible crash that sidelined his career for the rest of the year. The Interscope chassis was also destroyed in the crash, and with its meeting with the wall, Field’s days as an Indy 500 chassis constructor came to an end.

Nicknamed the “Batmobile” for its dark hue and wild looks, 1981’s Interscope was the right kind of creative and cool.




Photos courtesy Porsche North America


An incredible amount of work went into Porsche’s stillborn Indy 500 project from 1980. Ted Field brought his favorite German manufacturer to the table after finding great success with its products in sports car competition, and with Porsche on board to develop its legendary flat-six-cylinder turbo engine for a run at Indianapolis, the Speedway had a proper European invasion on the horizon.

Built around an existing Parnelli (Jones) chassis, the aforementioned Roman Slobodynskj mated the astonishingly powerful Porsche to his re-worked “Interscope” chassis and went about testing the car at the giant Ontario Motor Speedway oval near their shop in Southern California. Its refined aerodynamics worked well with the flat-sixes’ low center of gravity, and with the Porsche motor making use of big turbo boost pressure, it flew around Ontario.

Reports of the speeds achieved by Danny Ongais in the Interscope-Porsche, as the tale has been told, caught the attention of other Indy 500 entrants who successfully lobbied for a lower boost setting to be assigned to the car. Fearing an uncompetitive debut, Porsche pulled the plug before it could turn its first lap at Indy.

If there’s a silver lining to the entire process, the 1980 Interscope-Porsche project brought together an amazing team of mechanics, fabricators, designers, and crew. With their first car abandoned before it achieved its intended purpose, the response for 1981—Slobodynskj’s seriously fast Batmobile—would not have been as adventurous without the learning and ultimate sacrifice that took place with Interscope’s 1980 machine.

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5. 1912 CASE

Wisconsin’s J.I. Case Threshing Machine Company is better known for its farm equipment, but during the Teens and Twenties, it ventured into the exciting new world of automobile production. Case, in only its second year of auto manufacturing, sent three cars to compete in the inaugural Indy 500 and came away with little to show for their effort. Its comparatively small 284 cu. in. four-cylinder engines lacked power, and its chassis, which looked no different than most others, was somewhat underwhelming.

To fully appreciate the year-to-year transformation from Joe Jagersberger’s 1911 Case (TOP)  to Eddie Hearne’s 1912 model (BOTTOM), look no further than the teardrop body. The power of the Indy 500 is represented to perfection in both pictures.

With its first attempt at glory derailed by shortcomings, Case returned with an entirely new concept 12 months later. Gone was the boxy bodywork and fully exposed driver, replaced with the great race’s earliest race-inspired aerodynamic shape. If you’ve wondered which Indy car is considered the father of modern-day aerodynamic profiles used at the Speedway, this is it.

Case also worked on its power deficiency for 1912 and sent its cars to the 500 with a larger 450 cu. in. six-cylinder motor that allowed Hearne to qualify fifth. He would finish 20th after a burned bearing stopped his engine and teammate Louis Disbrow in the sister car placed 18th after differential problems intervened.

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I’m sure it’s a coincidence, but the late Bud Tingelstad appeared to have a knack for driving cars in the latter stages of his Indy 500 careers that featured all manner of pipes and radiators and trumpets to reduce straightline speeds.

The evolution of Tingelstad’s Gerhardt-Offy chassis starting in 1966 is father fascinating: For ’66 it sported a new ram-air intake for its non-turbo four-cylinder engine on the left side of the rear-engine car. By 1967, with a new Ford V8 at his disposal, the topside “hot vee” bundle-of-snakes exhausts climb high as they head up and over a duckbill tail. The Ford’s exhaust arrangement wasn’t out of the ordinary, but the tall oil cooler sticking up into the airstream near the right-rear corner didn’t help. And for 1968, the Gerhardt, now with a turbo Offy in the back, appears to make use of the same oil cooler shifted to the left of the car where a sidepod would rest today.

Three years, three unique engine installations, and three grassroots approaches to aerodynamic solutions to feed or cool those engines.


About The Author

Marshall Pruett

Marshall Pruett transitioned from more than 20 years as an open-wheel and sports car mechanic, engineer and team manager into his current role as a writer and reporter in 2006. Follow him @MarshallPruett []

You ask what other car might be stranger than the Eagle Aviation Eagle Chevy. What about the Stein Porsche twin, powered by two flat six Porsche engines? Maybe not strange aerodynamically, but strange nonetheless.