No matter what anybody tells you, size does matter when it comes to the harmonic balancer you use on an engine. Putting an incorrectly-sized balancer on an engine will do more than just cause it to not reach its full performance potential … it will cause serious damage to the rotating assembly.

One of the main items to consider when you’re trying to decide what balancer size you need is the amount of crankshaft torsional vibration control that’s required for your engine. This actually can be more of a personal preference since you need to look at the degree of durability and performance you want versus the amount of throttle response available.

According to Brian LeBarron from Fluidampr, going with too small of a balancer will bring on some serious problems for your engine.

“It sounds counterintuitive when the trend is to lighten everything, but harmonic balancers weigh what they do for a reason. A too small or light damper will not do as good a job controlling torsional vibration.  Vibration will pass through the engine where it can lead to lost power, premature bearing wear, and inaccurate timing. Worst-case scenario it can lead to oil pump and possibly crankshaft failure.”

To illustrate the differences of what different-size balancers do, LeBarron uses a big-block Chevy as an example.

“In Fluidampr’s line of balancers for 396 – 427-inch big-block Chevy applications, we offer 6-1/4-inch, 7-1/4-inch and 8-inch sized balancers. In drag racing applications the 8-inch is the most popular because it can handle the straight-out power the engines put out. In dirt track racing, the 6-1/4-inch and 7-1/4-inch are popular because they help provide a little faster throttle response coming out of the corners. That’s simply popular preference. You can use a 6-1/4-inch in drag racing but the tradeoff comes in durability and performance.”

If you want to learn more about how to correctly size a harmonic balancer for your application, make sure you check out the Fluidampr website right here for more information.