Between the two huge chunks of concrete in the moody dusk photo above is the world largest jet engine, which was recently assembled by General Electric engineers. It's the first working prototype of the GE9X turbofan engine, which GE is putting through the paces at the company's test range near Peebles, Ohio. You might be wondering just how huge the world's largest engine is. According to GE, "Shaquille O'Neil would fit inside it with Kobe Bryant sitting on his shoulders."