Editing V6 engine (section)

==== 120 degrees ====
At first glance, 120 degrees might seem to be the optimal V-angle for a V6 engine, since pairs of pistons in alternate banks can share crank pins in a three-throw crankshaft and the combustion forces are balanced by the firing interval being equal to the angle between the cylinder banks. A 120 degree configuration, unlike the 60 degree or 90 degree configurations, would not require crankshafts with flying arms, split crankpins, or seven main bearings to be even-firing. However, the primary imbalance caused by odd number of cylinders in each bank still remains in a 120 degree V6 engine. This differs from the perfect balance achieved by a 90 degree V8 engine with a commonly used [[crossplane]] crankshaft, because the inline-four engine in each bank of the V8 engine does not have this primary imbalance.

A 120 degree design also results in a large width for the engine, being only slightly narrower than a [[flat-six engine]] (which does not have the balance problems of the V6 engine). Therefore, the flat-six engine has been used in various automobiles, whereas use of the 120 degree V6 engine has been limited to a few truck and racing car engines, with the exception of the [[McLaren M630 engine]], which uses a 120 degree bank angle with a single balance shaft to eliminate all primary couples. The M630 also takes advantage of the wide angle by placing the turbochargers inside the vee, commonly referred to as a 'hot vee' configuration. The Ferrari 296 GTB is the first Ferrari road car to sport a V6 turbo with a vee angle of 120 degrees between the cylinder banks.