This is the Bugatti Veyron’s “EB 16.4” engine.

The current 2015 “Grand Sport Vitesse” Veyron engine along with the World Record holding “SS” version are powered by an 8-liter, 16 cylinder engine. Bugatti took two V-8 engines and bolted them together plus they added 4 turbochargers (quad-turbo) to get its current 1,200hp.