My first commercial 1/24 scale car was powered by a pitman motor, they were a large open style motor (looked like something you'd find in an erector set), they were the hottest set up in their day. Then the open style inline motors came along (tyco I believe), followed by the enclosed inline style (mabuci). The mabuci style motors were smaller, lighter and faster, made the other types extinct.
Wasn't long after the mabuci type motors became popular that I learned to advance the comutator and shim the magnets to go even faster. Soon after I was rewinding them for even more speed. Next thing I knew I was building commercial tracks, selling modified motors and scratch built frames.
Years later, my son grew older and wanted to try them out. Closest track was a few hours drive away, so I built a track on the rear patio, then built a room over the track. All the neighbor hood kids had a lot of fun (including me)!!!