Exploded View of Porsche 917 12-Cylinder Engine

I shot these May of last year while taking a tour on the Porsche Museum. If you haven’t been you need to take the time.

These engines are incredible. Notice how much they have in common with the 6-cylinder 911 engine. One big difference other than the obvious is that the flywheel is not bolted to the crankshaft. The power runs from a power take off that is driven from the middle of the crankshaft. On a crankshaft this long you would have too much torsional twist which could cause a crank to break. Also notice that the camshafts are driven at the middle as well. Imagine the timing difference from one end of that long camshaft to the other if they were driven from one end instead of in the middle. Fascinating engine!