Known as the Beast of Turin this Fiat S76 has lied dormant for over a century.  Now its restoration has been beautifully documented a 3 minute video clip. 
The 28.5 litre overhead cam motor (the largest car engine ever built) boasts four valves per cylinder and uses multi-spark technology.
A fellow actually hand cranks it to life for the first time on 100 years!  
A sight to behold here: 

Fiat S76 Beast of Turin (old photo)