Engine or Motor
 

People who work on them distinguish between the electrically powered unit called the “motor” and the internal combustion unit called the "engine".
Even in auto-parts stores the stuff which by that logic should be called “engine oil” is marketed as “motor oil.” Similarly, we go motoring on motorways. You can buy a powerful engine for your motorboat or should that be engineboat.
You could be asked 'what kind of motor are you running about in these days'.

So what is the difference.

http://en.wikipedia.org/wiki/Engine
http://en.wikipedia.org/wiki/Motors