engine room vs mechanics

engine room

noun
  • A compartment on a ship in which the engine machinery is located. 

  • The front row. 

  • The midfield. 

  • The pair of locks in a team. 

  • The source of power in a team or other group. 

mechanics

noun
  • The design and construction of machines. 

  • The branch of physics that deals with the action of forces on material objects with mass 

  • Spelling and punctuation. 

  • Operation in general; workings. 

How often have the words engine room and mechanics occurred in a corpus of books? (source: Google Ngram Viewer )