The German firm of Mercedes-Benz, long famed for its leadership in automotive development, has such engines housed in a stable of sleek prototype grand touring coupes that have never been sold to the public. These so-called C-l 11 machines were introduced in 1969-70 and carried a variety of three-and four-rotor rotary engines. They were reputed to have top speeds approaching 200 mph and prompted rumors that Mercedes-Benz might enter lightweight racing versions in the big international endurance races at Le Mans or Daytona. But the C-111s have never run on other than selected test tracks in Germany, and no one outside the tight-lipped Mercedes-Benz hierarchy has a clear picture of why the cars were built in the first place. As for creating a rotary engine for use in such ultra-exotic races as Indianapolis or Formula I, Rudolph Uhlenhaut, the now-retired chief engineer of the firm, is said to have told insiders of the Indianapolis Motor Speedway Establishment that perhaps three years and $5 million would be necessary to develop a winning rotary-engine car for the annual 500-mile race.
One man has made some noises about the rotary engine on the domestic racing scene, but his present situation is unclear. Andy Granatelli, the engine-additive tycoon and incomparable promoter, has made periodic and veiled reference to his firm's supersecret development of a Wankel engine for Indianapolis, but very little is known of the project.
Andy isn't talking, although he has understood the potential of the power plant for some time. In 1968 he approached Curtiss-Wright with a proposal to purchase four specially built, 240-cu.-in., four-rotor racing Wankels for Indianapolis. Thanks to a loophole in the rules (since closed), Wankels of this type could have produced over 800 hp fueled by alcohol-methanol blends. Granatelli's plan was conceived to encore his fabulous turbine cars, but something went awry. "Curtiss-Wright dropped the ball," says a former employee. " 'Some-body at the top couldn't see the value of such a program, and the whole thing fell into a crack somewhere along the line." Had Granatelli been able to appear at the 1969 Indianapolis 500 with a Wankel-powered car, he might have advanced public awareness of the new power plant much faster than can be imagined.
"Aside from occasional rumors that float around about Granatelli's project, we hear very little conversation about the rotary engine," says United Slates Auto Club official Dick King, a man deeply involved in affairs at Indy. "The present rules make it difficult to gain a clear-cut advantage with the engine and that makes the risks of development very high indeed."
There is one corporation that has the money, the technical capability and perhaps the motivation to field a Wankel engine in racing. That is General Motors—and most particularly its Chevrolet division, which has given massive sub rosa support to racing despite corporate anticompetition policies. The Can-Am, with its liberal rules, would seem an ideal place for Chevrolet to step in. The GM urge to develop a Can-Am power plant also might have been stimulated by the results of the 1972 season—a season that witnessed the end of the six-year domination of the series by Chevrolet-powered cars at the hands of the turbocharged Porsches of George Follmer, Mark Donohue and Roger Penske. But the Chevrolet engineering staff seems too involved in making the rotary suitable for domestic-car use to spend time and money on racing. "I went to Chevrolet and asked them to develop a four-rotor Can-Am engine, but they just weren't interested," says Bobby Rinzler, a friendly Georgia millionaire who sponsors a frontline Can-Am team. "I know the engine would be a world-beater, but without the big boys to help, the thing isn't even worth thinking about."
This year Rinzler will field two Porsches for the Can-Am. Like the others, they will carry reciprocating engines.