eccvets

I think in the end, you have to use a watts meter to check if your prop size is ok for your esc/motor/battery combo. Even if someone uses the same exact setup as the one you are thinking of does not gaurentee that the amps the motor will be using with that prop will be the same. I highly suggest either making your own or buying one. I oped to buy one cuz I dont have the time or patients to build/make my own and with a bought one like from wattsup meter, you can see 3 or 4 settings at the same time continously running all at the same time which gives you a lot better idea whats going on with your system.

How heavy is your plane? the stock mabuchi motor (I'm assuming its a 7.2v version) puts out about 2220 kv which is a lot more then the alpha 400 (920kv) brushless motor although it is probaly more efficient. Are you planning on using a prop which is a lot bigger?

I have been personnaly looking at the 2212-6 motor from suppo AKA the grayson hobby (ParkJet Combo) 2212-06 V2 (Super-Sonic) Brushless Combo [SuperSonic C] http://www.graysonhobby.com/catalog/...roducts_id=414 Although I have found it on ebay for 20 bucks for the motor and 30amp esc which is half the price as grayson. IDK how Grayson has upgraded theirs (I heard theirs are special) but idk whats so good about them. With a 6X4 prop with it, it seems to keep the amps below 30 and puts out 24 oz (perhaps more) of thrust for a pusher jet using a 3S Lipo. Takes about 2weeks or so to ship from China/Hong Kong though but the shipping is free.

What made you pick the Alpha 400 (920kv) brushless motor in the first place?

You can try a GraysonHobby Super MegaJet V2 & GH 50A ESC wtih 3Amp Ext BEC
[SuperMega -] http://www.graysonhobby.com/catalog/...roducts_id=645 . I'm pretty sure your piper cub will fly pretty quick with this motor and the below props... In fact the wings might rip off with all that thrust

Prop	Voltage	Current	Watts	Pitch Speed	RPM	Thrust (oz)
6 x 4 APC	11.1V	28A	316W	79.2 MPH	20910	32 oz
6 x 4 APC	14.8V	37A	491W	88 MPH	22110	38 oz