My understanding of the two terms is, any device which creates power on its own is an engine. A motor converts an external power source.

A turbo charger is a motor and a turbine is an engine.

The one which always confused me was, "What do you call a rocket?"

They are not really an engine because they have no moving parts and any force created is not really power.

They are not a motor because their power is self created.

And yet we have heard them called both "rocket engines" and "motors"

I believe the "Motor" in both the Ford and GM names come from when the products they made were referred to as, "Motorized carriages" and the mis-nomer simply carried over.

The terms "motor" and "engine" became intermingled and both are used. "Motor" is commonly used to describe any power plant whereas "engine" is a specific type of device. So, as much as it makes me cringe, it is indeed proper to install "motor mounts" to support your internal combustion engine in the frame.

Why do we call some people "politicians" when "self-serving, power-seeking, lying pond scum" is available?