Brushless motor question

[KyleRC]

Does anyone know the difference between 3660 motors and 550s I’ve never had a 550 and was wondering why there are different numbers for motors. Is it possible 36XX motors are just a different measure. Let me know what you think thanks!

 

[Heyitsme]

A 550 brushed is roughly 36 x 57 when a actual number is given for a brushless motor is given such as a 3660 brushless motor it is those dimensions. Now when something is designated as a 550 brushless motor it can vary in length but still be 36mm cans from what I have seen there is no standard in the end I still look at the can measurements not that it's called a 550 brushless motor.