Hi Tom, thanks for the BD greetings. Yes the Philco dryer has a rather strange motor in it. Its a two speed reversing motor, but its reverse speed is slower than the fwd speed. Fwd speed is the standard 1725rpm, but reverse speed (or if LOW speed drying is selected) is approx 1475rpm. Since the fan reverses with the motor, there is almost no pitch (angle) on the fan blades. Most all fan blades in other dryers have some pitch or angle to the blades. This is why no other fan will really work in this dryer. The reverse tumbling is a very interesting concept and would probably help keep clothes from tangling. All in all, its a fabulous dryer, and Philco/Ford went all out to realy try to make a glamorous dryer, when dryers as a rule are not real exciting........