ORIGINAL: 1QwkSport2.5r
I suppose a "car" jig using the standard car clutch and flywheel, and fashioning a spur gear setup to drive some sort of "load" would work. This is far more complicated than I would want to get into but it could be made to work.
Thats what I had in mind. If you clutch the engine, it should be able to be disengaged when throttled down so the flywheel doesnt overtake the engine. Worked on my heli.
OTOH if you were to use pulleys to go something like 2-1 and offset the prop so it isnt blowing directly on the engine, you could do something like that too. Spin the prop at 20k with the motor at 40K. Just make sure you use a good prop that can handle that speed. You can probably take a piece of angle iron, put some slots tor the mounts so you can adjust the belt tension, and bolt that to a sturdy bench as a test stand.
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