Exploded view of the 500cc 1955 Moto Guzzi GP engine. Liquid cooled 90° V8 with gear-driven cams- what? not 4 valves per cylinder? Looks fairly straightforward, until it's installed in the frame of a 325 lb motorcycle. Then (bottom) all that incredible complexity is hidden behind a plain, slab-sided fairing.
1957 version with dustbin fairing, cutaway drawing by Bill Bennett for Classic Bike.