Start on liquid-piston X-Engine build.

@Poppy Ott - The "Liquid" part is form before they arrived at this new design, when they originally were planning to literally use liquid for pistons.
Many of their patents are now expired, so I'm surprised there's still nobody selling any of these - if I had to guess, they probably have a longevity problem? The only users of their tech are weapons, where the engine only needs to run one time.

The first internal combustion engines used "liquid" piston, water with a person operating the valve. These were used to pump water out of mines and later pumping water for irrigation. The largest that is still operational is in Australia that is a diesel water piston pump for irrigation out of concrete and is like 10 ft. or 3 m in diameter. Your going to find lots of old patents.
I got interested it a liquid piston engine using a liquid ring compressor or vacuum pump that are extremely robust. Dozens of patents exist on them. There is even a Archimedes screw style with no valves. These compressors and vacuum pumps can handle slugs of liquid, sand, rocks, mud, etc. The Archimedes being by far the most robust since not rotating seals are needed. It can likely hand long fibers. The liquid ring touching the OD of the shaft where the screw is attached is the valve and seal between the chambers. However; Unless it is huge and spinning at a very high speed the water head, pressure it can achieve. is not in the range of the pressure in a combustion engine. Failure.
The reason they dropped the actual use of liquid is that is just adds cost and complexity unless the goal is hydraulic fluid power. Your bace to

cnd said:

@Poppy Ott - The "Liquid" part is form before they arrived at this new design, when they originally were planning to literally use liquid for pistons.
Many of their patents are now expired, so I'm surprised there's still nobody selling any of these - if I had to guess, they probably have a longevity problem? The only users of their tech are weapons, where the engine only needs to run one time.

Click to expand...

The original internal combustion engines had water pistons for moving water out of mines and to irrigate fields. The mass of the water being accelerated in a contained cylinder allowed for the development of pressures associated with internal combustion compression and then expansion of the combustion gases. For covering to rotary motion this is a complex, inefficient, big, and heavy approach. That is why the stopped.

I have looked at the "liquid" piston engine. It is never going to reach the market in my opinion because it seems to ignored the reason why the Wankel engine never made it. Side leakage due to the gap needed to deal with the hotter rotor expansion. I could make a ceramic Wankel rotor or a composite rotor with a ceramic core. May even find a ceramic that shrinks as it heats up. However; the thin walls of the Liquid Piston make this impossible. I can not think of any ceramic capable of taking multiple detonations.
A better choice is the Omega 1 by Astron Aerospace. It has a separate compressor and combustion chamber and expander so more power can be achieved. It does have side seals issues but the rotors can be cooled and the cylinders are simple. Need some gears. https://www.karmactive.com/astron-a...is-be-the-renaissance-of-internal-combustion/ https://www.whichcar.com.au/feature...-engine-is-reviving-the-rotary-engine-concept