Alkaline - I got a 46 FX in mine. What I ended up doing(this is the second one now) was cutting off the "cheeks" and mounted the engine sideways with the muffler hanging below. Oh, and I added retracts and beefed up the wing. Also re-covered totally in chrome monokote. Only two flights on it so far, but
easy unlimited vertical. Just so you know it's possible. [8D]
Nice planes ya'll, Sounds like pretty good performance on E-power.
