Advantages/Disadvantages To lightening a crankshaft

[440dart_72]

Hey guys

What are the advantages/disadvantages to lightening a crankshaft?

[deadhorse66]

It depends on the application. Lighter crankshafts will decrease rotating mass, providing for quicker acceleration and higher rpm potential. You wouldn't really want a light crank in an engine that is being used primarily for pulling/low end torque, because the extra weight increases reciprocating momentum, and can aid in the lower portion of the rpm range of the motor, especially with engines backed by manual transmissions. Lightweight cranks are designed primarily for high rpm engines in lightweight cars that see more rpms upwards of 6500 than they do below 6500 (i.e. oval track, drag cars, those Honda v-tecs that sound like overgrown chainsaws when they spin to 10,000). The typical street driven American V8 doesn't usually go that high, and therefore it is unnecessary to use a lightweight crank. BTW-it is usually cheaper to buy a lighter crank than to have a stock one lightened.