A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders each, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft. Since each cylinder bank is essentially a straight-six which is by itself in both primary and secondary balance, a V12 is automatically in primary and secondary balance no matter which V angle is used, and therefore it needs no balance shafts.
The V12 engines are one of the smoothest running engines that exists. It’s two inline six cylinders matched to a common crankshaft, so it’s inherently balanced at any V orientation. Also, because it has more cylinders than an I6, the power strokes overlap more and thus power delivery is smoother. The V12 has been used in many exotic brands, such as Ferrari, Lamborghini, and Pagani.
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