Electric motor

Using a higher voltage motor is highly advisable! What you need is HORSEPOWER, and if none of the electric power is wasted, (100% Efficient motor and wiring+controller) it will require 2,238 watts of electricity to make just 3 horsepower! Realistically, things are NOT "100% efficient" so you could easily need 3,000 watts to generate 3 horsepower. Getting 3,000 watts from a 12 volt battery would result in currents around 300 amperes, but doing the same thing with 48 volts would require currents around 75 amperes, which is much easier to handle! I used the "3 horsepower" figure as a starting point, as this represents the power available from a typical small, "Lawn mower" type gasoline engine, as found on small, cheap go-karts. If more "Sporting" type performance is desired, consider using 72 volts or more, with something like an "ETECK" electric motor, and a 400 ampere controller.-This can provide 15 to 20 horsepower!Battery selection is very important, due to the high rate of discharge and high currents drawn. Lithium Polymer or Lithium Iron/Phosphate batteries are to be desired in such applications, as automobile/boat type "Lead-Acid" batteries are too big/heavy/short-lived in such usage.-NO, it will not be CHEAP, unless you can get donations!-Bob