The Revolutionary 6-Stroke Engine replaces alternatively. A fuel intake stroke with a water intake stroke. Making it a 6-stroke engine. The water intake stroke is to make use of the heat in the block. The water gets turned into steam. Which then makes it a steam-powered stroke. Although not really the same. It did remind me of adding water/water vapor to the air intake side. An application that has been around for years. For example, Roger Maynard's water vapor injection system boosts your miles per gallon. I have included a video down below.

10 Jan 2024 - Water-Powered ICE Is Here!!! | The Revolutionary 6-Stroke Engine - Ft-share International

Here is an explanation of Roger Maynard's water vapor injection system to boost your MPG.

20 May 2020 - Boost your mpg with water - Patrick Kelly 

In terms of modern setups, you can buy water/methanol injection kits for your car. This is directed at getting more horsepower. Here is a video explaining the setup with a turbo. How and why it works.

15 Oct 2015 - Water Methanol Injection - More Boost! - Engineering Explained