Page "Crankshaft" Paragraph 24

The configuration and number of pistons in relation to each other and the crank leads to straight, V or flat engines.

The same basic engine block can be used with different crankshafts, however, to alter the firing order ; for instance, the 90 ° V6 engine configuration, in older days sometimes derived by using six cylinders of a V8 engine with what is basically a shortened version of the V8 crankshaft, produces an engine with an inherent pulsation in the power flow due to the " missing " two cylinders.

The same engine, however, can be made to provide evenly spaced power pulses by using a crankshaft with an individual crank throw for each cylinder, spaced so that the pistons are actually phased 120 ° apart, as in the GM 3800 engine.

While production V8 engines use four crank throws spaced 90 ° apart, high-performance V8 engines often use a " flat " crankshaft with throws spaced 180 ° apart.

The difference can be heard as the flat-plane crankshafts result in the engine having a smoother, higher-pitched sound than cross-plane ( for example, IRL IndyCar Series compared to NASCAR Nextel Cup, or a Ferrari 355 compared to a Chevrolet Corvette ).

See the main article on crossplane crankshafts.