I feel I am on the edge of OT here but found it very interesting and think it would be fun to try to power a model boat with one.
I have heard about this engine before but had not seen any thing in print (can we call stuff on the internet "in print?) about it before. When I first heard about it it was being developed for third world use. We have a place about 30 miles from us where they develop ways of surviving for Third World environments using found things. Someting made from every day/ found stuff to do needed work like cooking, heating pumping water and generating elctricity. Were it not for the fact it could also be used to power a boat I would guess this would be a little OT

They were expirmenting with either this engine or one similar to it.
About the flexable shaft drive. That is nothing new. It has been around for a very long time. It has been used to drive gas pumps, sewing machines, juke boxes and many other things which require a universal joint/drive shaft. The cable is layer braided, not twisted. You can run it either direction.
The engine supposedly needs very low pressure steqam to run it. They are talking bout waste water from and engine use in operating it.
When I first heard about it one supposedly ran an automobile alternator using only the steam pressure from a stove top tea kettle.

if ypu find typos and misspelling. I have suddenly developed a very strong numbness in both of my hands and find typing a pain. On top of that my spellcheck has quit. :rant
Bill