Two million rotaries from Mazda

PRODUCTION of Mazda’s internal combustion rotary engine has passed the two million unit milestone, according to estimates from the Hiroshima, Japan-based automaker.

Mazda licensed the rotary engine, developed by German inventor (and WWII Nazi Party office bearer) Felix Wankel, from German automaker NSU in a 1961 technical tie up eventually fitting it under the bonnet of its groundbreaking 1967 Cosmo Sport (Mazda 110S) coupe.

The engine had already made an appearance in a production car powering the single-rotor NSU Spider of 1963 and then the stylish, twin rotor NSU RO-80 around the same time as the Mazda Cosmo.

But in Mazda’s hands through continuing R&D it became a better mouse trap despite ongoing issues with sealing the ends of the rotating triangles (epitrochoids) that replace the pistons in an Ottocycle engine.

The rotary engine has a “unique” turbine-like structure that uses rotational movement of these triangular rotors to generate power. After the Cosmo, Mazda ramped up production of the rotary engine as buyer acceptance grew accompanied by the RX-7 sports car and motor sport successes.

Mazda adopted a program of continuous development of the rotary engine, refining it, increasing performance, improving fuel economy and durability while simultaneously maintaining its position as the only automaker mass-producing rotary engines.

The rotary engine was used in many different Mazda models including small coupes, sportscars, four door sedans and even found its way under the bonnet of a Holden Kingswood (Roadpacer). Other manufacturers have also used the technology notably the big four Japanese motorcycle manufacturers and some European motorcycle brands like Hercules/DKW, Norton and Van Veen.

Disappointing legion rotary engine tragics, the “rotisserie” fizzled over 10 years ago, Mazda producing the final RX-8 rotary in 2012 that utilised the naturally aspirated and low torque Renesis series engine.

But bubbling away in the background, the Japanese automaker was planning a resurrection of the silky-smooth engine starting production in June this year of a new rotary powered model called the Mazda MX-30 e-SKYACTIV R-EV that uses the engine as an electricity generator feeding a battery and then the drive motor(s).

At the recent Japan Mobility Show, Mazda further showed its hand regarding the rotary engine in the form of its ICONIC SP coupe vision study that uses a two-rotor EV system that it says demonstrates the high degree of layout flexibility and future development potential that the rotary powertrain continues to offer.

Director and senior managing executive officer at Mazda, Takeshi Mukai, made the following statement in response to reaching two million total production units.

“The rotary engine is a special part of Mazda history and represents our ‘never-stop challenging spirit.’ The rotary engine is much loved by customers around the world, and we are excited to resume production and see it make a comeback.

“I would like to take this opportunity to sincerely thank everyone who has supported us on this journey—in particular, the many customers who have purchased rotary engine vehicles, our rotary engine fans, and all our business partners who were involved in development and production. 

“Moving forward, we will continue to pass on this 'never-stop challenging spirit,’ offering attractive vehicles that provide our customers with an exciting driving experience even in the age of electrification.”