Toyota has filed a patent application for an engine that includes water injection valves to intake ports for the combustion chamber. CarBuzz discovered the patent at the United States Patent and Trademark Office.
The patent explains that the water could either be injected as the intake valve is opening or as it's closing, meaning that it won't be spraying constantly. Toyota says it's no biggie if water flows into the cylinder as it will evaporate if the droplets are small enough. If water makes it through to the crankcase, it may mix with the oil, but it's more likely it will evaporate due to the internal pressure.
This particular patent is for a hydrogen fuel engine, but not like the unit you'll find in a Toyota Mirai. This is a hydrogen combustion engine, which is an entirely different design.
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