Savannah-Tom,
The University of Idaho testing is available at this link.
http://itd.idaho.gov/planning/research/ ... bution.pdfIt is public information. The increased thermal efficiency is the key. Nearly all the heat of the ethanol combustion was absorbed by the water portion and captured to produce steam energy. That is why there is little or no heat at the exhaust.
The steam was visible on initial startup in the Watertown demonstration until operating temperatures were reached, then it disappeared. In Sand Point when we demonstrated for the OEM who flew in their VP's of engineering for the show, it continued to exhaust steam even after warmup. Considering the relative humidities and temperatures in Sand Point it was suspected that the cooler and more humid air was preventing immediate evaporation. A dew point issue.
As far as running backwards like a regular steam engine, that is only limited by the type of engine that is converted. General motors ported two stroke diesels can be run backwards. We had one in a Michigan payloader that would run in reverse if killed on a hard uphill push. Unfortunately it would intake through the muffler and exhaust through the air filter. It sooted up the air filter and if you didn't shut it down you could ruin the engine because the oil pump did not provide pressure in that direction. I understand that large maritime diesels can run in reverse to eliminate transmissions that cause efficiency losses.
In the steam powered plane video the thing that I wondered about was the possibility of icing up your own wing or elevator. Now that could be a problem.