Zooks, the Sterling cycle? We have a couple models of Sterling engines in work, as well as an antique Sterling engine. It's a fun gadget and I think it has a lot of untapped potential. When the internal combustion engine was invented and fuel was cheap, the Sterling engine was put on the back burner. But as fuel gets more expensive they will again become interesting and practical. There's tons written about it online, but here's a link with good info:
Stirling Technology, Inc. | Stirling Engines: Uses
All you need to make it do work is a temperature difference. That will allow it to rotate a crank to run a pump, a well, a generator, etc. This animation will give you the idea; the hot side doesn't have to be a fire, all you need is a temp difference; and you can see the finned radiator here is just loosing heat to the atmosphere on the cold end:
Here's an old water pumping Sterling engine but it uses a firebox to make the hot side. The one we have in work is a smaller version of this:
