Japan's 'Big Four' exploring hydrogen engines By Ben Purvis
Japan's 'Big Four' are considering working together to work on hydrogen-fuelled combustion engines, which promise to be carbon-neutral and nearly emissions-free while retaining the feel, performance characteristics and sound that we're familiar with. Initially Yamaha and Kawasaki hope to work together on hydrogen engine development, with Honda and Suzuki expected to join the effort at a later date.
Kawasaki showed its first step towards a hydrogen motorcycle engine last year, revealing a direct fuel-injected version of the supercharged H2 four-cylinder. While that prototype currently runs on petrol, not hydrogen, the development of direct injection tech is vital in the pursuit of making hydrogen engines work.
If mixed with air before entering the cylinder, the volume of hydrogen would take up too much space, even though the ideal stoichiometric ratio is around 34:1 - far lower than for petrol engines. That would leave less space for air in the cylinder, reducing power by around 15% compared to petrol. In contrast, using direct-injected hydrogen raises power compared to a petrol engine by about the same percentage.
What's more, most hydrogen combustion engine prototypes are designed to use far more air than necessary for combustion, effectively running extremely lean, to reduce NOx emissions. To achieve that, forced induction is required, hence Kawasaki's decision to base its project on the supercharged H2 motor.
We've yet to see the result of the Yamaha-Kawasaki cooperation, but Yamaha has revealed its own hydrogen-powered combustion engine in the form of a V8 that it's developing on behalf of Toyota. This five-litre monster is based on an existing Toyota unit. With 450 hp and 540 Nm of torque, its performance is roughly on a par with the stock Toyota petrol version.
"We are working toward achieving carbon neutrality by 2050," said Yamaha Motor president Yoshihiro Hidaka. "At the same time, 'Motor' is in our company name, and we accordingly have a strong passion for and level of commitment to the internal combustion engine."
Although the deal to develop hydrogen motorcycle engines with Kawasaki has yet to be completed, Yamaha's announcement says: "Kawasaki and Yamaha Motor have started considerations toward the joint development of a hydrogen engine for possible use in two-wheeled vehicles".
What's more, they plan to add Honda and Suzuki to the arrangement later on, saying: "The four companies intend to jointly explore the possibility of achieving carbon neutrality through the use of internal combustion engines in two-wheeled vehicles. To maintain a distinct line between cooperation and competition, they intend to proceed after establishing a framework that will clearly define areas of cooperation and collaborative research".
