Water Injection in engines has been around for a long time. No as a power source but to allow higher performance to be extracted prior to pre-detonation? It acts as a coolant to allow higher temperatures to be used during the power cycle.
https://www.youtube.com/watch?v=EWFztpnQuPA - Recent
There is even a section on it in the RR Merlin Wiki
https://en.wikipedia.org/wiki/Rolls-Royce_Merlin I have not met anyone nuts enough to try it on a car but do know a few loons who have done nitros. I figure it makes the world safer for the rest of us if we watch what goes wrong with the sticky-bit-of-the-envelope club first!
