Mazda revives R&D team to accelerate rotary engine development

Nicolaus Otto and other engineers developed the internal combustion engine at the end of the 19^th century. From then on, it would become the propulsion unit for motorised vehicles and evolve in different ways. However, while there were many variations, the reciprocating concept is the one that has remained in consistent use for over 100 years.

Felix Wankel’s different approach
The only other approach has been the rotary concept which Felix Wankel came up with in the 1950s. Instead of pistons going up and down inside a cylindrical chamber, Wankel designed a triangular rotor that spun around inside a chamber.

The rotary engine, as it came to be known, appeared in a production car for the first time in 1964 and it seemed promising that many companies paid Wankel for a licence to make it. At least 25 companies, including major carmakers, took a licence and began their own development work.

There were challenges in commercialising the rotary engine and with demand for cars accelerating, most companies did not want to waste time and money overcoming those challenges. Eventually, they all ended their development programmes, except for one – Mazda.

Determined to succeed
Kenichi Yamamoto, the engineer in charge (later a Mazda president) of developing the rotary engine, saw the powerplant as a way for the company to stand out in the marketplace. He refused to give up and eventually came up with an engine that offered unusually high performance while being compact and light.

Small yet powerful
The first Mazda rotary engines were produced in 1967 and went into the futuristic Cosmo Sport. Mazda began to gain fame with new and different powerplant which also proved potent in motorsport. The RE (RX-2) with its 1121 cc rotary engine, for example, was able to challenge the bigger Alfa Romeos with 2-litre engines in series production races at the Batu Tiga and Penang Circuits in Malaysia.

As the only carmaker to mass-produce the rotary engine, Mazda offered it in many models as an alternative to the combustion engine. It sold a bus in Japan with the engine, and it even made a rotary-engined pick-up truck which was sold mostly in the USA in the 1970s.

Undesirable characteristics
Though Yamamoto and his team had made it possible to commercialise the engine, there were still some characteristics which were not desirable, especially as concerns for the environment and energy grew in the 1970s. The rotary engine generated a lot of toxic gases and also consumed fuel at a high rate.

Mazda developed REAPS, the Rotary Engine Anti-Pollution System to address the emission issue, but the consumption part was difficult to overcome. With the energy crisis going on, its rotary-engined models saw a decline in sales during the decade. Although the company continued to improve it in various ways, the appeal of the rotary engine diminished to the point that the company had to stop making it in 2012.

Discontinued… but not forgotten
Enthusiasts were saddened as the rotary engine seemed to be gone forever. But within the carmaker’s organisation, there were those who did not want it to become history. Occasionally, there would be a rumour that the rotary engine was coming back but Mazda would usually clarify that there were no specific plans yet.

Then in January 2023, the company announced that its new model, the MX-30, would have a small rotary engine in it. The MX-30 is an EV but uses the rotary engine (831 cc) as a power generator and not as the primary propulsion system. It is part of a new powertrain called e-SKYACTIV which is one of Mazda’s Multi Solution Approach strategies to achieve carbon neutrality.

To know more about the MX-30 in Malaysia, visit www.mazda.com.my.

Using the rotary engine in a new way
Just as in the 1960s, Mazda is again using a different approach for its cars and intends to accelerate its research and development of rotary engines. This has led to the reinstatement of the ‘RE Development Group’ in the Powertrain Technology Development Department of Powertrain Development Division this month.

This new group will provide the ‘prelude of a sequel to the RE story’, adapting the powerplant adapted to the new era of electrification. It will conduct R&D in areas such as regulatory compliance in major markets as well as the application of carbon-neutral fuels.

Symbol of Mazda’s ‘challenger spirit’
Commenting on this development, Director, Senior Managing Executive Officer, and Chief Technology Officer Ichiro Hirose said: “In Mazda’s history, the rotary engine is a special symbol of our ‘challenger spirit’. For the last 6 years, RE engineers have been part of the engine development organisation where they engaged in the development of state-of-the-art internal combustion engine functions as well as the ultimate improvement in efficiency. Those engineers have broadened their perspective beyond the boundaries of engine systems, and have trained themselves to master the ‘Model-Based Development,’ which is one of Mazda’s engineering strengths.”

“Now, 36 engineers will gather in one group to make a breakthrough in the research and development of RE. In the age of electrification and in a carbon-neutral society, we promise to keep delivering attractive cars that excite customers with our ‘challenger spirit’,” he said.

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