Kenichi Yamamoto, the man who led a team at Mazda to produce the world’s first commercially viable rotary engine and later served as its President and Chairman has died. He was 95.

Mr. Yamamoto began his career at Toyo Kogyo (Mazda Corporation’s name before 1984) right after World War II. A mechanical engineer by profession, he initially worked at the factory building transmissions for the Mazda-Go three-wheeled truck but soon shifted to engine design, accelerating his rise in the company.

In the early 1960s, with Mazda’s independence at stake, the then Toyo Kogyo President Tsuneji Matsuda asked Mr. Yamamoto to supervise a group of engineers who were trying to perfect the rotary engine. With few moving parts, the rotary engine was a compact alternative to conventional engines.

His team produced a successful engine which was first shown to the world at the Tokyo Motor Show in 1963. Under the hood of a prototype coupe called the Cosmo, Mr. Yamamoto patiently talked about this new technology along with Mr. Matsuda during the show’s entire two-week duration.

Four years later, the Cosmo 110S debuted, securing Mazda’s independence.

In the 1970s, as the world was gripped by the oil crisis, the rotary became a liability for Mazda because of its poor fuel economy. Close to bankruptcy, that didn’t stop Mr. Yamamoto to find a way to make the rotary engine efficient; after all, this breakthrough technology set them apart from their competitors.


Embarking on “Project Phoenix”, he and 47 other engineers (dubbed the 47 Ronin in the company) made the rotary engine’s fuel economy rise significantly and the resulting RX-7 became an instant hit.

Aside from developing the rotary engine, Mr. Yamamoto was also instrumental in the birth of the MX-5.

In 1978, Mr. Yamamoto listened to a pitch from motoring journalist Bob Hall about an inexpensive two-seater roadster. The idea did not progress until Hall found himself working at Mazda as a Product Planner in California.

In 1985, after Mr. Yamamoto became president, he recommended that the company’s board approve production of the car: the MX-5.

Mr. Yamamoto stepped down as Mazda’s chairman in 1997.

In 2003, he reminisced about pioneering the rotary engine, which went on to power 1.8 million Mazda vehicles.

“I am proud to be an engineer,” Mr. Yamamoto wrote, adding that he was happy to have helped develop an engine that “symbolized the magnificent union of technology and romance that took place in the latter half of the century.”