Why harmonic balancer

Each time a cylinder fires, a force acts upon the crankshaft, causing it to twist. But this force also causes vibrations in the crankshaft, and at certain frequencies, the shaft can resonate, which makes the vibrations even worse [source: Mach V ]. These vibrations from the engine can become too much for the crankshaft to bear, causing it to fail. And when that happens, your car won't run and you'll be facing some expensive repairs. This is where the harmonic balancer comes in.

The circular device, made of rubber and metal, is bolted at the front end of the crankshaft to help absorb vibrations. It's usually connected to the crank pulley, which drives accessories like the air conditioner. The rubber inside the pulley is what actually absorbs the vibrations and keeps them at a safe level.

In essence, the device is designed to help prevent crankshaft failure. It's also sometimes called a "dampener. However, the rubber material can deteriorate over time. So if your harmonic balancer is going bad, you could get rough engine vibrations, a cracked crankshaft, or even a serpentine belt that gets thrown off its track. Replacing one is excellent preventative maintenance, and that's exactly what we'll talk about next.

So you want to replace your harmonic balancer, huh? There's good news and bad news. First, the good news: Installing a new balancer is a relatively easy task.

While this part may not wear, or be known to wear, as quickly as a traditional idler pulley or belt tensioner, balancers do in fact wear and eventually must be replaced.

When a piston accelerates downward after the ignition of the fuel and air, the crankshaft speeds up and then slows down as it reaches the bottom of the stroke. These changes in speed are minimal, but big enough to cause problems.

Constantly changing and tuning race engines is what keeps teams competitive. With every change made, the harmonics of the engine change with it. A Fluidampr performance damper removes the guess work. It is engineered to protect over a wide band of frequencies throughout the entire rpm range, including high rpm. That means you can modify the engine and not worry if your harmonic balancer is properly tuned. Uncontrolled torsional vibration can damage and reduce the life of engine components.

Examples could be rapid wear on the camshaft lifter lobes, stretching of the timing chain, grooving of the timing chain sprockets, through to causing the flywheel to come loose on the crankshaft. The differences between an OEM and a high-performance harmonic damper would be clearly seen on a dynamometer. An increase in gas pressure in the combustion chamber equals an increased twisting force on the crankshaft throws.

This causes a deflection or twisting motion that is known as torsional vibration. The peaks of this back and forth motion are measured as amplitude. The function of the harmonic balancer is to reduce the amplitude of the torsional vibration peaks to an acceptable level. That is why racers must consider a high-performance damper that is fit for purpose. A stock damper is calibrated for a specific power level and rpm range, and as you go beyond that point, the stock-bonded rubber damper becomes less effective and can fail with the damper coming apart.

A performance harmonic damper that is SFI certified is calibrated for performance usage, and the SFI certification means that it has been tested to pass the containment standards in the event of a failure. Performance parts and power adders change the harmonics of the engine.

Factory balancers come tuned to a specific frequency. Drag cars have complete custom-built engines, there is no OE damper that will properly protect their engine.

We asked Orefice to explain the construction of a Fluidampr. Parts are precision machined, balanced, and assembled in our ISO certified machine shop located in Springville, N. The housing cover is laser welded with the inertia ring inside to create a leak-proof seal. We then pump silicone fluid into the shear gap through fill holes. Fluidampr is the leading viscous harmonic balancer in professional motorsports since Today, factory race teams and multiple OEMs trust Fluidampr for its superior quality and durability to protect their performance engines.

Stock dampers use an elastomer design that gets bonded together. A properly functioning damper also stabilizes camshaft and ignition timing. A reduction in twist at the end of the crank also stabilizes the valvetrain. The result is more power and longer engine life. About Us Contact Us. K1 Technologies. What Does a Harmonic Balancer do?

OEM dampers consists of an outer and inner ring bonded together with rubber. They are very effective in production cars but can deteriorate and fail over time due to exposure to the elements.

As the engine operates, harmonics from combustion resonate through the crank. The job of the balancer is to help eliminate these harmonics before the cause problems. In certain engine applications, the harmonic balancer is actually part of the engine balancing strategy. Weights are added to the balancer that offset the weight of the pistons and rods.

ATI Super Dampers use high durometer O-rings operating between the inner and outer ring to dampen crankshaft harmonics. Written by John Baechtel.