Balancing Equipment: Weighing the Options
In order to achieve the maximum performance and long component life, all rotating and reciprocal parts of an engine must be precision balanced.
By Brendan Baker
Engine balancing is an important part of the process of building a performance engine today. In order to achieve the maximum performance and long component life, all rotating and reciprocal parts of an engine must be precision balanced. To properly balance an engine requires specialized equipment to measure the amount of unbalance and to locate where to correct the unbalance with weight or other means.
A balancing machine is simply a measuring device used to find, locate and measure unbalance. Today's balancing machines allow you to change the distribution of mass via electronic readouts that graphically represent corrections, so that you may zero out the effects of many forces including pistons, rods and pins by adding or removing weight from certain locations on the crankshaft. Most of today's balancers measure balance as the absence of unbalance or a zero unbalance. Therefore, in effect, you are only measuring unbalance, not balance.
Every object has a natural center of gravity, no matter what its size or shape. When an object rotates it does so around this point. Crankshafts are balanced from the manufacturer with large counterweights to offset the forces created by the rotating and reciprocating parts such as the pistons, rods, flywheel, flexplate, harmonic balancer, etc. The crankshaft must maintain its own balance as it spins around as well as maintaining the balance of the other components that are attached to it. The force is balanced by not only matching the weight of the components but also by the speed in which they are spinning.
Corrections for unbalance are made either by adding mass to the crankshaft or by the removal of material (i.e., knife edging). The correction method you choose should ensure that there is enough space or material to allow for the correction of all the imbalance that may be present.
Balancing an engine can be a very profitable part of your business and is a service that is in demand with performance customers. The profiles on the following two pages show some of the latest balancing machines on the market today.