Yes, ENGINES is a Scrabble word!

Letter values in Scrabble US: E 1, N 1, G 2, I 1, N 1, E 1, S 1.

Is it a valid word?

ENGINES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

motor that converts thermal energy to mechanical work
something used to achieve a purpose
a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks
an instrument or machine that is used in warfare, such as a battering ram, catapult, artillery piece, etc.

Also: locomotive engine, railway locomotive.