When is Flat 12 a V12

We received some questions after posting the video below about calling the 512BBi motor a flat V-12. Mainly, if it is flat, then how can it be a v format?

The answer lies in a technicality. The moniker “boxer” refers to the piston timing of an engine, rather than the direction the cylinders point. On the Ferrari 512, the crankshaft isn’t a true boxer crankshaft – it is a V-12 crankshaft with the cylinders laid flat. Here’s why:

True boxers have one crankpin controlling only one piston/cylinder, and 180° engines share crankpins.

A true “boxer” (horizontally opposed engine) has corresponding pistons reaching top dead center simultaneously.

A 180° V-12 engine has piston pairs sharing a crank pin on the crankshaft and reaching top dead center half a crankshaft revolution apart. Most flat 12s are actually 180° V engines, including the Ferrari discussed here and the famous Porsche 917 racecar.

Interestingly, phase has always been of great concern to the motorcycle industry (think big bang configuration) as it directly effects vibration and riders sit right on top of it. Read more here.

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