I guess my first thought is that the performance of the 46 mentioned is a tad less than stellar. Engines this size on classics can be brought in the 13.5-14K range or better if tuned well. Of course I'm viewing this from a "classic pattern" perspective rather than a sport plane view.

My second thought is that the view of getting any prop of a given geometry turning at a given rpm is not particularly useful. For one, not all props are equal. An APC 11x6 sport is a different beast than its thin electric counterpart. Put an APC sport on the motor and you'll find out how the motor is really comparing to the glow...

What I would do though is to pick up an APC electric 11x8.5 and an 11x10 and spool up your system. You'll now see your motor come to life! Keep it within the current draw specs which I bet are at least 40 if not 50A. Now you'll be pulling ~880W on 40A or ~1100W on 50A. Keep the motor in its efficiency band and your Kaos will be a different beast. Want to fly slower? That's what the throttle stick's for. [8D]

From there on flight duration can be sorted through current draw. At 40A your battery will give you roughly 4.5 min at full throttle or ~8-10 min with throttle management.

Hopefully someone who has done an e-conversion of the model will chime in as well.

David