Bernhard is also building a Jenny. He got stuck on motor, so I bought one for him when I ordered motors for my PT-15. He wanted it to be an inrunner to allow for water cooling, so I found an inrunner with a low kV rating and presumably high torque. This should make for running a quite large propeller, at lower speed, which should be more efficient.
I took a few pictures of the motor. It seems very well constructed.
Motor name: Turnigy 540L V-Spec Inrunner with impeller
Dimension: 58mm x 36mm, 72mm(with shaft)
Weight: 173g (kv1025) (not including connectors)
Diameter of shaft: 5mm
Length of front shaft: 14mm
Battery: 3-4 Cell 4S/14.8V
Max current: 40A
The motor should be about the same size as a size 600 motor. I am looking forward to see how the motor performs in Bernhard's boat. I expect it to run quite well