I just converted a 40 size heckler to electric. went from a .56 saito to a turnigy g-46 550 kv motor, 60 amp speed control and a 3300 4s lipo(40 c)
I am impressed, first 8 minutes it has more power than the saito by quite a bit. hovers at 1/2-2/3 power. pulls out of a hover great. rest of the flight ( to 12.5 minutes) is still very spirited but not like the first 8. throttle management just sport flying i could easily see this thing run 18-20 minutes. next batt will probably be a 4200 4s. I am also going to switch out the 14/8 for a 15/6 or 8 for a little more thrust. AUW is 4 pounds, 48" wing span and 41" long. motor batt and esc is 29 oz's
here is the battery, esc and motor i purchased for it.
http://www.hobbyking.com/hobbyking/s...dProduct=19027
http://www.hobbyking.com/hobbyking/s...idProduct=2166
http://www.hobbyking.com/hobbyking/s...dProduct=15004