The weird and wonderful cars of the ‘500,’ part 3

Published On April 12, 2016 » 7930 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 47 days to go, racing journalist Marshall Pruett continues his look back at milestone cars and technology.

More Pruett: 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.

A week ago we featured Part 2 and a week before that came Part 1 in our look back at a handful of 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 3.


1. 1990 March 90P

Porsche took a final swing at IndyCar racing in 1990 with its custom chassis manufactured by March and a pair of radical drivetrain designs that failed to bear fruit.

The March 90P-Porsche serves as the last true outside-the-box entry at the Indy 500, and that distinction was earned with the placement of its turbocharger. All of its contemporaries—cars from Lola and Penske—placed the heavy turbos behind the engine in a cavity between the flywheel and transmission. Searching for ways to improve its weight distribution, which would then improve handling, Porsche and March went the opposite direction and fitted the 2.65-liter V8’s turbo in front of the engine.

To accommodate the giant mass of glowing-hot steel, March manufactured the carbon-fiber/aluminum honeycomb chassis with a sizeable recess behind the roll hoop, and packed a ton of heat shielding in the area to keep the turbo from boiling the contents of the fuel tank directly below.


The turbo was hard to miss on the 90P, thanks to its exit at the left-front corner of the engine cover. The Porsche team, led by Derrick Walker, affixed a stainless steel heat shield to the engine cover to keep it from going up in flames. The March also used a comparatively tiny gearbox which, like the turbo layout, worked well on paper, yet offered very little in the way of real gains.

John Andretti was able to qualify 10th with the sleek car, but crashed in the race, and teammate Teo Fabi retired with gearbox failure. With Porsche’s return to Formula 1 on the horizon, the German brand’s last stand in IndyCar fell silent at the conclusion of the 1990 season.

As a sidebar, Porsche’s March 90P can be credited as the car that pushed the Indy 500 towards full carbon-fiber tubs which are still used today.

March originally built the 90P as a full-carbon car, and whether it was politically motivated by constructors who were not prepared to go that route and pressured CART, or it was a true misunderstanding between March/Porsche and the series, CART disallowed the carbon 90P and required March to manufacture new cars using the standard of the time: bottom halves constructed from aluminum/honeycomb, and top halves were done in carbon. From the wrangling with the March-Porsche, and the general advancement of carbon-fiber construction, CART permitted all-carbon tubs in 1991.


2. 1926 Eldridge Special

Welcome to the first Indy 500 car that fits the spirit of the low-slung, streamlined cars that we’ve come to know and love. Everything about the chassis and bodywork was different from its contemporaries; the Eldridge’s ride height stands out first and foremost. Ground clearance on most Indy cars from the first race in 1911 through 1925 could be measured in feet, yet with the Eldridge, driver W.D. Hawkes was sitting just inches above the track.

The car’s shapely body was also a break from tradition, and from the tip of the nose to the tapered tail, Hawkes and the little four-cylinder Anzani engine were able to slice through the air with great efficiency. Persistent motor problems resulted in 12 long pit stops for Hawkes. A frozen camshaft left the trend-setting Eldridge 14th at the finish of the 1926 race.




3. The Mallard

It’s a front-engine roadster, has a nice and sleek body design like the other roadsters of the day and wears old-style Firestones with miniature grooves in the treads. At first glance, the Mallard chassis could easily be mistaken for something from a late-1950s or early-1960s qualifying photo at Indianapolis, but this four-wheeled submarine was actually designed and built for the 1967 Indy 500. Famed driver Jim Hurtubise and his brother Pete created the car from scratch, fitted it with an Offenhauser four-cylinder engine, and tried—in vain—to make the show.

Massively overweight and underpowered, “Herk” went to turbocharging—the newest and hottest technology for 1968, and with a boosted Offy installed, he summoned enough courage and sling the Mallard around the 2.5-mile speedway to set the 30th-fastest speed.

Herk’s average of 162.1 mph was well shy of the 171.5 mph pole set by Joe Leonard in the Turbine’s pole. Engine problems meant the Mallard would finish where it started, and emboldened by making the field in 1968, Hurtubise continued to develop the car through 1971. Small canards were added to the rounded nose, an all-new wedge-shape nose was tried, and more creative thinking was applied, but as speeds increased as the rear-engine formula grew, the Mallard was hopelessly outclassed.

With its participation in the 1968 Indy 500, the front-engine roadster formula came to a close with the Mallard.


4. 1938 Marchese Special

Driver Harry McQuinn and the 1938 Marchese Special deserve a small footnote in Indy 500 history. The car, which was powered by an eight-cylinder Miller engine, is believed to be the first car to use sidepod-mounted radiators.

A few cars prior to the Marchese Special used external fuel tanks located in the same approximate area alongside the driver, but the Marchese took the concept to new heights by removing the radiator from its standard position at the front of the car.

Most cars using front-mount radiators met the air like an inverted umbrella. Air went through the radiator, into the engine bay, and made contact with a variety of surfaces that created aerodynamic drag before the air found its way out. With the Miller’s cooling needs moved to the side, the Marchese’s nose section could be closed, and with the crisp tapering job seen in the photo, a slick aerodynamic advancement was made.

McQuinn finished seventh in the 1938 Indy 500.



5. 1981 Longhorn

If it worked in Formula 1, why not the Indy 500? Crossover technology from Indy to F1 and back was common at the 500, and in this instance, it was the F1 World Championship-winning Williams FW07 that served as the direct inspiration for the chassis driven by Al Unser in 1981.

Bobby Hillin, father of NASCAR driver Bobby Hillin Jr., struck a deal with F1 team owner Frank Williams to acquire blueprints for the FW07 Alan Jones drove to the 1980 F1 title, had the car constructed in Texas, and also relied on Williams to supply some componentry to complete the Cosworth DFX-powered “Longhorn” LR-02.

With the bodywork removed, it’s impossible to tell the FW07’s aluminum monocoque from the Longhorn, and Hillin deserves credit for his lateral thinking. With ground effects having taken over F1, and Johnny Rutherford’s domination of the 1980 Indy 500 using the F1-inspired Chaparral 2K which featured enormous underwings, striking a deal to essentially copy the FW07 for use in Indy car was an inspired move.

Forget the timely and expensive development a brand-new ground effects design would require; Hillin bypassed the entire process and made his own version of the title-winning Williams. Al Unser qualified a competitive ninth, but encountered problems in the race, placing 17th.

The Longhorn development continued in 1982, where the exposed turbocharger from ’81 was mostly tucked into a new engine cover. The single-post rear wing was also replaced by a smaller wing, using a pair of vertical mounts that doubled as endplates.

Altogether, the significant changes to the Longhorn’s aerodynamic package allowed Unser to finish fifth in the car’s final appearance at the 500.



6. 1937 Oldfield-Marmon

Jack Brabham’s Cooper chassis is often credited for sparking Indy’s rear-engine revolution in 1961. Although the F1-derived machine was responsible for the eventual move from front-engine roadsters to the type of Indy cars we continue to use in 2016, Lee Oldfield’s massively inspired rear-engine car from the 1937 Indy 500 should be recognized as the first of its kind at the Speedway.

Oldfield, possibly taking a page from the rear-engine Auto Union grand prix cars of the same era, managed to produce Indy’s first rear-engine car, which was remarkable on its own, and also broke new ground in other areas. The homebuilt car was, without a doubt, one of the more agricultural attempts at chassis manufacturing.

Despite its lack of aesthetic appeal, the Marmon V16-powered car featured inboard brakes at the rear, and also made use of independent a-arm suspension—a great and forward-looking departure in 1937.

The car was late arriving to Indy and with limited track time, and the apparent use of truck tires, the rear-engine Oldfield-Marmon failed to qualify. Even with its rough edges, the car caught the attention of Indy’s finest minds, and by 1938, the 500’s first proper rear-engine design was on the grid.

More on that car, and some of the wildest Speedway creations, next week in our fourth installement.


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 []