Paul,  what happened to the little prop dyno that you had mounted on
a trailer?  I have been waiting for  you to use it,  to see what
changes if any you would recommend, before building one for
myself.    Could  you put Mark's engine on it?   BTW,  I have no need
for the trailer version.  Mine could be solid mounted bolted down to
the shop floor.   Jerry

The house project is eating all my spare time.
Extend the bottom legs further up under the engine
to balance it better. You don't need the static thrust
measuring capability as it can be misleading.
Rather than the bathroom scale there are other ways
of measuring the torque. A calibrated garage door
spring is one of them. Use a shock absorber to damp
out any oscillation.

Let me know if you need any advice.

Paul Lamar ...No rotor no motor.

I need LOTS of advice.  Can I supply resistance without running a
prop?   I have heard of driving a pump.  Would it be belt driven off
the prop flange?   Jerry

Do you have a 200 HP water pump? Takes a lot of v belts to
transfer 200 HP. Do you have a lake on the property?