ORIGINAL: ACES&8s
T/Y Rob...I have read the specs from the Extreme guys in Australia...good news is inrunners have more thrust per watt...cooling is an issue and the arc motors are way too expensive to buy...if I were a pro I'd use one, but I don't get this stuff for free.
I saw the Velocity Cool 42 on Ebay
http://www.ebay.com/itm/Velocity-RC-...item1c1dff5fb4
for 89.99 and 9.50 shipping...was wondering about the electrical comparison, but I may be overthinking this...the Velocity is going into this fan....
http://www.hobbyking.com/hobbyking/s..._Fan_Unit.html
I wouldn't advise using a 4200KV motor with a Change Sun 10 blade from anyone. It will draw about 180 amps on 4S. I have a Neu 1112/1Y 3500KV 4S in a CS10 and it uses 139 amps on takeoff with a fresh battery. I fly mostly at 1/2 throttle. The Cool42 might work with 3S but it isn't really a good choice. An ARC 28-58-1 on 4S would be a better choice for high RPM use.