Electric flight is generally rated in terms of watts per pound of aircraft when talking about performance. For unlimited performance you are looking around 150 watts per pound. For good aerobatic performance, somewhere around 100-125 watts per pound. The way I do it is to look at the flying weight of the plane = 24 oz in your case = 1.5lbs, and then figure out total watts for unlimited performance 1.5lbs x 150 watts per lb = 225 total watts of power required. Now find a motor that is capable of delivering that. If total watts is not listed for the motor, take the amps the motor draws on a continuous basis, and multiply by the voltage supplied to the motor to get watts.
If you are looking at a 3 cell LiPo = rated at 11.1 volts, it actually hits 12.6 when fully charged and 9.9 volts when empty. So a median voltage would be 11.25 volts. Take the 225 total watts of power and divide by the 11.25 median voltage and you get 20 amps. So to have unlimited performance at all times, you would need a motor capable of 20 amps continuous, while accepting/capable of a 3 cell LiPo.
Now this is a lot of power on a continuous basis, I like to have unlimited performance when I get up to about 80% throttle. but it is a starting point.
Hope it helps
