NIFTE Engines Non-Inertia-Feedback-Thermofluidic Engines   This basic design was done by a gentleman named T.C.B Smith and his original design was intended for large power companies.   I think they also make good small engines for personal use.

As far as I understand the operation of these, they work like this. Hot water heats the gas and liquid in the top of the left heat exchanger which pressurizes the loop and causes the fluid piston to push down on the piston and the same time pushes the fluid below the hot end of the exchanger to the cool end . A small oriface or control valve allows the  fluid in the loop side to slowly fill back up into the  cool side of the condenser and causes the vaporised fluid to recondense from the loop tube. This allow the piston to move back up and the system starts again. It’s supposed to cycle fairly quickly and my small version that I made did so. This is a diagram of a small version I tried to test out the idea. I just used my hand temperature around the coil to provide heat and it did work so I tried designing some that would be big enough to do actual work. The rest of the pictures in this section are just the various designs I came up with. This one is just a very basic system showing what is needed for a minimum setup.    The following pictures are my various attempts at designing a system where it puts out useful power  System supplies compressed air and electrical power.  System supplies compressed air and electrical power.  Same as above, slightly different setup  Supplies compressed air only  Early design, just pumps water  Another system to supply compressed air or electricity  System pumps it’s own water like above, can use two different heat sources and provides a pump output