Japan has just achieved the impossible

Kawasaki is leading the race to create a zero-emission motorcycle engine by some margin, which they proved recently with a public test run at the Suzuka circuit in Japan. Their hydrogen-fueled prototype internal combustion engine put on an eye-opening showing on the track, and it’s clear that the motorcycle powerhouse plans to throw its all behind the ambitious hydrogen project. With a worldwide focus on reducing carbon emissions, all eyes are on Kawasaki’s converted Ninja H2.

Kawasaki unveils zero-emission hydrogen prototype motorcycle at Suzuka circuit

The public got their first taste of Kawasaki’s hydrogen power at the Suzuka race circuit in Japan during the motorcycle engine’s debut on July 20, 2024, ahead of the Suzuka 8 Hours race. The demonstration has ignited a wave of interest in the future of zero-emission engines for ‘small’ vehicles, especially considering that hydrogen fuel, by nature, requires more space on the frame to deliver the necessary level of performance.

Earlier footage of the engine running laps at the Autopolis international circuit is catching attention as people hone in on the huge hydrogen tanks mounted on the side. The system also incorporates a back-mounted filling port and several cylinders designed to handle a severe pressure load.

Although the Suzuka outing was the first public showcasing of the two-wheeled incarnation, the hydrogen engine actually made an appearance in January at the Dakar 2024 rally in the form of the HySE-X1 four-wheeler. Suzuki, Toyota, Yamaha, Honda, and Kawasaki united to form the HySE research association in May 2023, and this collaboration, aimed at developing hydrogen options for smaller vehicles, is already bearing fruit.

Kawasaki says there’s still a long wait for a fully functional hydrogen-fueled ICE

Kawasaki revealed that testing of the bike engine began in early 2024, leading to the July showing just half a year later. But the conception stage dates back to October 2021, when they released the design of a four-cylinder 998cc Ninja H2 revised to accommodate hydrogen. It didn’t take long before a model on paper appeared in November 2022, followed by the real thing in December 2023.

Despite the speedy conceptualisation-to-testing process of three years, Suzuki says there’s still a long wait ahead:

“[We are] currently conducting research and development with the aim of realizing a functioning hydrogen ICE motorcycle as one carbon-neutral option for riders in the early 2030s.”

How will the converted Ninja H2 accommodate hydrogen?

Supercharging is virtually essential in a hydrogen-powered combustion engine, so the Ninja H2 998cc engine was an obvious choice as a base for Kawasaki’s green bike model. The combustion engine has been converted to handle a significantly higher fuel-to-air ratio, which is a factor when working with hydrogen. This is where the supercharger comes in, compressing the air ahead of entering the cylinder.

Fuel injection was another essential factor in adapting the Ninja H2. Hydrogen is added to the combustion process after the inlet valves have closed, avoiding the expansion of the gas forcing air out the cylinder.

Kawasaki had some tricky corners to get around when considering fuel storage. The previously mentioned video of the bike shows the display passing 4,900 psi (340 bar) of pressure, meaning a similar load to that of hydrogen feul cars like that Honda Clarity must be accounted for. Even at pressure, hydrogen requires more room than gasoline with an equivalent energy output. So for now, the sizeable rear storage panniers, which are accommodated by an especially robust chassis, will have to stay. You can forget about a passenger or much luggage, too.

It’s not all bad, though. The bulkiness of the hydrogen storage tanks doesn’t necessarily mean weight, because hydrogen is way lighter than gasoline. Nevertheless, Kawasaki’s original design on paper suggested a way less cumbersome frame than the reality presented at Suzuka, and no doubt, the team are looking at reducing bulk as a practical priority.