In May 1967, Mazda began selling the world’s first dual-rotor rotary engine car, the Cosmo Sport.
It featured the 110-horsepower Type 10A engine (2 x 491cc) equipped with newly developed high-strength carbon-based apex seals, made by permeating pyrographite with aluminum molecules through a special sintering process. This type of apex seal resulted from Mazda’s independent development work and was proven durable and reliable through 1,000 hours of continuous testing. Even after a 100,000 km test drive, it showed only slight wear and none of the chatter marks known as “nail marks of the Devil.”
The intake system featured a side-port configuration coupled with a two-stage four-barrel carburetor, to keep combustion stable at all speeds. For the ignition system, each rotor was equipped with two spark plugs so that stable combustion could be maintained in cold and hot weather conditions alike, and on both highways and city streets. The Cosmo Sport recorded more than 3 million kilometers of road tests over six years. Its futuristic styling and superb driving performance delighted sports car enthusiasts throughout the world.
After successfully commencing mass production of the Type 10A dual-rotor RE with the Cosmo Sport in 1967, Mazda decided to expand its application beyond the limited sports car market, and began installing it in large-volume sedans and coupes in 1968. In an effort to meet demand from global markets, the company also decided to export its rotary-engine vehicles.
Exports to the United States began In June 1970, when the U.S. government was in the process of introducing the Muskie Act, the country’s most stringent automobile emission standards to date.
1971 Mazda Cosmo Sport L10B-11120 – sold for $121,000
This second-series Cosmo, freshly restored in Japan, has recently arrived in the United States for the first time. During the comprehensive work, the Mazda was expertly restored using many new old stock parts, resulting in a superb and correct example that is impressively detailed throughout and surely among the finest examples in the world today. There were few available options, the most desirable of which was air conditioning. This Cosmo is one of those so equipped, which is a godsend for its occupants given the car’s airy greenhouse. It is visually stunning, finished in the classic white over the standard black interior, which is accented by houndstooth cloth inserts to the seats and deep red carpeting. Auction Source: RM Sotheby’s Monterey 2015