Hello!
I am searching for info about car heater motors.
I am building a model boat (project image is my avatar) and when considering propulsion I got two used car heater motors to test. One is from Opel Astra F, produced by Siemens, which ran at 20A max when powered by the car's battery with the turbine still attached to the shaft, at about 4000 rpm. The other is from Renault 19, produced by Valeo. With the turbine and housing (a load test of a kind) it ran at 3000 rpm on 12V with 16A consumption. The Siemens motor is awfully heavy (over 1kg), while the Valeo is less than 500g. Both motors have enough grunt for any application imaginable, however I am concerned about their cooling. Every permanent magnet dc motor I have seen has a tiny turbine wheel attached to the axle, while both these motors do not. I understand that the air flow through and around them caused by their turbines has cooled the motors enough in their original places, but I am not sure how the one I choose will fare in the closed space of the hull without cooling. Could any of you with experience share some info on how you have solved this problem, or if there is a problem at all in the first place? My setup will most likely be one motor running two prop shafts with propellers about 50 mm in dia and 1,3-1,4 pitch via belt drives on a composite planning hull 1.2m long and 25cm wide.
Thank you!