Friends..Colleagues..modellers..nowadays ECMs are getting inexpensive..and yes, powerful and maint: free, when compared to a Brushed motor..but the sheer power from an ECM never come with ease..it will eat a big ampereage, while running..but my experience shows, that the brushed motors are still good for displacement and heavy crafts, with ease, while eating very less current..so, runs for a long time..and is very easy to make an ESC, with reverse, if we are using a brushed motor..but one of the main problem is with any motor is over heating, especially when use a powerful motor..and usually we looks for some extra ordinary ideas to cool a motor..but here see a simplest possible idea to cool a brushed motor, may be in any size, and type..
yes, i know all you know, but still have some cool simple way..take a drinking straw, a thick one is preffered, or can take copper tube, will be difficult to work, or a body of a ball point pen, anything that feel apropriate, in to a desired length..
fill some fine sand, in to the tube, and heat it up with cigar lighter, and bend it to a l shape..copper or steel must be heated up with gas torch, or on a gas stove burner..