Kawasaki Motors is working on a new piston aviation engine initiative and hopes to have the first four- and six-cylinder inline models type certified as early as 2030. The company is designing the models to initially run on traditional combustion fuels, but with the capacity for transitioning to hydrogen and e-fuels depending on customer needs. These engines will offer high power-to-weight ratios and are designed to be compact and low-vibration, drawing from what the company has learned in decades of motorcycle engine development.

The name Kawasaki certainly invokes motorcycles, but the company has also been active in aerospace engineering since its early days, and now both operations fall under the umbrella of Kawasaki Heavy Industries. In the early 20th century, Kawasaki developed both airframes and aircraft engines, with the Ki-61 Hien “flying swallow” WWII fighter as one of its most recognizable. Now, development is coming full circle with innovation springing from the ground up with the clean-sheet development of a piston aircraft engine informed by motorcycle technology.

According to the company, the 310-hp Ninja H2R motorcycle engine is the highest-performing motorcycle engine. Kawasaki has developed a hydrogen internal combustion engine (ICE) for its world-first hydrogen-powered motorcycle, the Ninja H2 SX, which debuted in July last year.

“When you start thinking about the power-to-weight ratio, it’s going to be a good fit with making the right changes to meet the requirements for the aviation application, which is different from the motorcycle,” said Yuichiro “Jamie” Imai, manager of Kawasaki’s business planning department, at Aero Friedrichshafen on Thursday. “But when you think about the fundamentals, the basic design of the engine, our belief is that we carry extensive experience and knowledge to design a good engine.”

“We will be working on running the engine by gasoline to begin with,” he continued. “And the reason for that is us coming from the automotive side: That’s the field which we understand the most… And once we complete that, we will be working on other alternative fuels as well, hydrogen as well as e-fuel, and actually, hydrogen is already in the works right now back in Japan.”

Imai introduced Satoaki Ichi, who was the development leader for the Ninja H2R/H2 and worked on the high-performance engine development. As of April 1, said Imai, Ichi has been appointed as deputy general manager of the newly created Kawasaki Aviation Systems Group, with an eye to the development of a hydrogen-fueled aircraft engine.

“One of the reasons why we started to think about hydrogen in the aviation engine is when people talk about hydrogen aircraft, and even within Kawasaki, where we have a working relationship working on larger commercial hydrogen aircraft, I think the people see all those images of a huge fuel tank,” Imai said. But the piston engine has a fuel consumption to output advantage, he said.

In May 2023, Kawasaki and other automotive brands including Yamaha, Suzuki, Honda, and Toyota formed a research body because, with hydrogen engine technology still in its infancy, the companies decided that collaboration would be better than competition.

“What’s even nicer is we decided to kind of split our area of responsibility when it comes to research,” to make the process more efficient, said Imai. “And in the end, if we can just share the findings, everybody’s going to win. That’s how we work back in Japan, and so far, it’s been working very, very well.”