It's an engine not a motor
I know engine people use the terms interchangeably, but they're not. A motor is an electric motor - made out of copper, iron and insulating varnish, it contains nothing to endanger flight. So don't go by what the materials guidelines say about "motors".
Why does this matter? You may be shipping an engine, but other ...
Surprisingly, there's logic in forbidden items in checked in luggage: is it going to endanger the aircraft? Is it corrosive, explosive, flammable in other words. They don't really care about anything else.
In specifics, this is what the TSA has to say about Engine-powered Equipment Completely Purged of Fuel
Checked Bags: Check with Airline
No amount of ...
Out of personal experience, there is no problem as long as it is new and it has no oils or some sort of residue that might leak.
I have put RC plane engines in checked luggage many times, some of them are more than a 100cc. One time we also put an RC jet engine in a checked luggage with no issues at all.
Terminal 4 at Madrid airport consists of 2 buildings - the main 'T4' building which contains all of the check-in counters, baggage claim, etc, and a "Satellite" terminal, 'T4S'. These two buildings are connected via a automated train that takes about 4 minutes to go between buildings.
Your itinerary will always list "T4" regardless of ...