@Bob Delbridge a lot has to do with the gear ratios. If you don't mind, I would love to know what the gear ratios are on your Lionel 4-8-2, Atlas F3 and Williams J. You can determine this without hurting the loco, by turning the flywheel by hand, and counting the number of turns it takes for one revolution of the driving wheels. (Make a small mark with a pencil or marker on each.)
Sometimes if you know the make and model number of the motor, you can find the "no load RPM" listed. The in-service speed will be about 80-85% of that at the rated voltage. So if you know the motor and you know the gear ratio, you can figure out how fast your locos will go. What I've found is that 90% of 3-rail locos are geared way too fast! There's almost no reason for a model train to go more than 65 scale mph on a typical home layout. Even 45 mph looks pretty fast from an on-board or trackside camera.
Thanks for sharing, and I would love to hear more!
