In the headquarters of Detroit's automakers, executive desk tops and coffee tables have lately sprouted plastic models of a strange-looking engine, and in high-level conversations around them, knowing mentions are made of something called an epitrochoid. Visitors soon learn that the models are see-through likenesses of the Wankel rotary engine—and an epitrochoid, in case they did not know, is the bloated figure-eight shape that its rotor follows when moving. Both the baubles and the vocabulary are just two more signs that the long-discussed Wankel has finally shifted up from being Detroit's vague "engine of the future" to a much more imminent status. The auto industry's growing number of Wankel watchers, including the authoritative trade magazine Ward's Auto World, an early booster, predict that Detroit will be mass-producing rotary engines in three years or so, and that by the end of the decade, more than half of all new domestic cars will be powered by them.
Coattails. The Wankel revolution has been expected for years, chiefly because of the rotary engine's elegant simplicity. Instead of converting up-and-down piston motion into wheel-driving circular energy through a series of complex linkages—the way a standard engine works—the Wankel rotors spin continuously and thus provide the proper torque to move a car's wheels directly. Rotary engines are smaller, peppier and potentially cheaper to build than conventional reciprocating models, and have only six major points of wear, v. 100 in a conventional engine. The most persistent bug, ever since Inventor Felix Wankel (pronounced Van-kel) introduced his first complete model in 1957, has been a tendency for the rotor tips to wear down too quickly. That problem apparently has been solved with modern metal-coating processes, but the rotary engine still has at least one major disadvantage. It uses about 10% more fuel than standard engines at high speeds, thus adding to consumer costs and in effect wasting an already precious natural resource.*
Detroit's Big Three are pushing extensive, top-secret research projects on the Wankel, and investors and businessmen are already revving up to cut themselves in on the profits. Except for General Motors, which in 1970 bought a license to make Wankels in a deal that will eventually cost it $50 million, any manufacturer who decides to build a rotary engine will presumably have to pay royalties to Curtiss-Wright Corp., which owns North American patent rights to the design. Largely on the strength of that asset, Curtiss-Wright stock shot up from 1 ⅜ to 59 ¼ earlier this year, though it has settled back in recent weeks to around 45. Officers of machine tool firms are hoping to produce assembly-line equipment for what could be the biggest car design change ever made.
The boomlet has been helped along considerably by the reception given to the first rotary-powered car available in the U.S., Japan's smooth-riding and exceptionally zippy Mazda (TIME, April 5, 1971). Some 20,000 Mazdas were sold last year, even though the car has been made available in only 20 states. Mazda already ranks as the seventh biggest-selling import. Toyo Kogyo, the manufacturer, has received no fewer than 2,300 applications for some 100 Eastern and Midwestern dealerships that will be awarded this summer and fall.