If you have seen a photo of a Boeing 777X, you've probably noticed how large its engines are. But to answer the question from the title, we need to analyze both the aircraft and the engine in detail.

Picture a large-displacement piston engine in your mind. Perhaps the first image to come up is an engine you'd see in construction equipment, like the 20-cylinder quad-turbo 106-liter powerplant from ...

The title of largest engine ever installed in a production car goes to the Pierce-Arrow Model 66, built between 1910 and 1918. It was powered by a massive 13.5-liter straight-six engine, displacing ...