There's a show on right now about the history of the engine, from steam powered engines to today's gas powered engines, electric, hybrids, rotary, etc.
This one guy made an "engine" that worked, made up of 78 molecules

There was one part I found interesting. Every "expert" they interviewed in different fields of engines/motors, had different definitions and thoughts on the difference between an "engine" and a "motor"
So guys, what is your definition and the difference between the two?

 

an engine uses some type of "fuel" to produce power.
a motor uses some type of electrical source to produce power.
Motor veh's use "engines"
HVAC uses "motors"

 

what ls1 said is how i have always seen it

 

i was watchin that show earlier too...there was a turbine jet engine that was the size of a postage stamp. and another motor that was 10 atoms wide....can't even be seen with a microscope, just know it's there.