Project Wankel: When Car and Driver Built a Rotary Race Car
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In the summer of 1973, the editors of Car and Driver decided to do something unusual. Instead of just writing about the rotary engine, they decided to test it the hard way. They poured about half their annual editorial budget into building a Mazda RX-2 for IMSA Baby Grand racing, all to answer one question: "What will this little sweethear do, anyway? How mch horsepower will it make if you really try."
At the time, the rotary engine felt like the future. It was smaller, smoother, and lighter than a traditional piston engine, and it seemed to make an impressive amount of power for its size. To its believers, it looked like it might actually replace the piston engine altogether.
That dream had been building for decades. Felix Wankel imagined a “valveless” engine as early as 1929. By the 1960s, NSU had helped bring the concept to life, first with the NSU Spider and then with the futuristic Ro 80. In Japan, Mazda embraced the technology with unusual determination, launching the Cosmo Sport in 1967 and staking a big part of its identity on the rotary.
By the time Car and Driver picked up its tools in 1973, rotaries had already proven they were more than a gimmick. Mazda had built a serious reputation in racing, and rotary-powered cars had already shown they could survive punishment and win. That is what made Project Wankel so interesting. This was not the first rotary race car. It was a magazine deciding to find out, in public, whether a rotary could beat piston-engine rivals in the United States on equal terms.
The Heart of the Beast
The project began with a stock Mazda RX-2 engine from Hiroshima making 95 horsepower. Respectable for a street car, but not enough for what the Car and Driver team had in mind. They handed the engine to Jim Mederer of Racing Beat, one of the few people in the country who truly understood how to make a rotary go faster.
When he was done, the little engine was making 198 horsepower at 8,300 rpm. That was a shocking number for such a small package.
How did they get 200 horses out of a tiny 1.2L engine?
The eyebrow trick: Since rotaries do not use valves like piston engines, they breathe through ports. Mederer enlarged and reshaped those openings with bridgeporting, adding an extra “eyebrow” above the stock intake port to help the engine gulp in more air and fuel.
The megaphone: The exhaust was tuned with two pipes merging into a megaphone-style outlet. It was designed to help the engine breathe at high rpm, and it gave the car a voice that was anything but subtle.
The supporting science: The carburetor was opened up to match the new airflow, and the ignition system was upgraded so the engine could survive and perform at sustained high speeds.
The "Certain Death" Problem
There was, of course, a catch.
For the rotary, that catch was heat.
The builders called overheating “certain death,” and they were not exaggerating. The engine was built like a five-layer metal sandwich, with aluminum housings clamped between cast-iron plates. If the engine overheated, the aluminum could soften and distort under pressure. If it was pushed hard before it fully warmed up, localized heat could damage the engine just as quickly. Either way, the result could be the same: a ruined engine.
That was one of the most important lessons of Project Wankel. The rotary could make big power, but it demanded precision. It rewarded careful tuning and punished carelessness.
Building a Survivor
The engine was only half the challenge. The car itself had to survive the experiment.
The suspension was reworked to lower the RX-2 and help it handle the added performance. The interior was stripped and fitted with a custom dash and a 10,000-rpm tachometer, because an ordinary gauge would not have been enough. For safety, the team added a full roll cage and a dry-break fueling system for pit stops. This was not a magazine stunt. It was a serious attempt to build a race car around a very unconventional engine.
What They Actually Learned
What they learned from Project Wankel was both exciting and humbling.
Yes, they did go on to race the car, but the reality was a little more human and a little less heroic than a clean underdog victory story. They missed their first race at Daytona because the car was not finished in time. The build took twice as long and 50 percent more money than expected. They were constantly dealing with compromises, delays, and learning on the fly. That matters because this was not a polished factory effort. It was a magazine team trying to act like a race team.
When the car did make it to IMSA events, it was not a dominant, headline-grabbing success. It was more of a rolling experiment. But that experiment proved something important. The rotary was not a gimmick. It could make serious power from a tiny package, rev incredibly high, and run with conventional engines on the track. At the same time, it demanded patience, respect, and a lot of mechanical discipline. Heat management was critical. Durability was never guaranteed. Small mistakes could destroy an engine quickly.
In the end, Project Wankel did not prove that the rotary would replace the piston engine. It proved something more interesting: in the right hands, it could be brilliant, but it would never be easy.
A Legacy of Winning
Mazda’s famous commercials back then claimed the rotary "hummed" while piston engines went "boing, boing, boing." The Car and Driver staff had a correction: This car didn't hum. It screamed. And that scream was heard on podiums for decades. While the 1973 project was a wild experiment, Mazda’s later victories made the engine legendary.
IMSA Dominance: The Mazda RX-7 went on to win the 24 Hours of Daytona in 1979 and proceeded to win the IMSA GTU championship seven years in a row.
Global Glory: In 1981, an RX-7 won the Spa 24 Hours overall, the first time a Japanese brand had ever done so.
The Holy Grail: Everything culminated in 1991 when the quad-rotor Mazda 787B won the 24 Hours of Le Mans outright. It remains the first and only car with a non-piston engine to ever win the world's most famous endurance race.
Want to learn more about rotary engines and other bold engineering ideas that challenged convention? Visit the Tampa Bay Automobile Museum and explore the vehicles and inventions that dared to be different.
Source: Car and Driver, “Project Wankel,” July 1973 issue.