Find the right damper

When identifying your existing damper (balancer), look on the back side. This is not visible if the damper is mounted on the engine. If your damper has no offset in the casting or weight, then you have an internal (neutral) style damper. If you do see the offset in the casting or a weight, you have what is classified as an external damper, commonly used on all 400 SBC engines.

Be sure of what you need before purchasing. You will definitely know if you have the wrong damper on the engine, as it will have a serious vibration. Remember, neutral dampers, have no weights or offset in the casting. They are perfectly balanced, hence the term "neutral".

We recommend replacing the mounting bolt and washer when installing a new damper.

THE PRO/RACE LINE OF DAMPERS IS ONE OF THE BEST ON THE MARKET, AND IS USED EXCLUSIVELY ON ALL OUR IN HOUSE ENGINE BUILDS.

• Precision machined from steel much stronger than OEM stock
• Outer ring and hub are bonded together to prevent slippage
• Correct crank bore for proper fit to crankshaft
• High gloss steel finish with black timing marks plus marks at every 90°
• RPM Rating: to 12000 RPM

It's a very wise investment when building an engine to replace the damper. This is an elastomer type damper, much like the ones from the factory. The principal component to their operation is a bonded elastomer ring which adheres to the inertia ring and hub, and they are far superior in design to the OEM stock dampers. If you're considering using your old, possibly original damper, then you should know there is a great chance the elastomer band has dry rot and is not adhering as it should to the inner ring and outer hub. If this is the case, then damaging harmonics are not dampened as they should be.

If your original damper is not functioning as it should, you will not notice it, as it has little to do with how much vibration is transferred into the vehicle. You simply can't base the condition of your damper on whether or not you can feel it in the car or not. It would be fair to say if your damper is more than 15 years old it is not functioning the way it should.

One more good reason to replace the damper is the poorly visible timing marks on the OEM damper. This makes it nearly impossible to set your timing properly. One feature about the Pro Race line of dampers is the highly visible timing marks. We find this priceless when it comes to setting timing on an engine. Your view to the damper is often limited in most cars, and being able to see the timing marks is a must.

We have seen other dampers on the market for less money, and we have purchased them. We have found such dampers to be very low in quality and appearance, and the timing marks are hardly visible. These no name, low cost dampers could also break under high rpm if the metal is not properly cast. We also found the diameter of the center to be slightly undersized, requiring the need for broaching. Such dampers are being sold online from various performance car parts companies that appear to have no regard for the safety or function of the product.

When you receive your damper, you will notice the high quality appearance. We carry most of the Pro Race line, and consider them a first rate product.

A note from Skip White, president.

We have seen others market a knockoff, no name damper that has to be the worst product on the market. We have nothing against knockoff products, but some are worth warning about. These low quality dampers being sold by many have a poor appearance and the center hole is often out of spec, with a dull finish. The casting was not machine finished; it was rough cast, as you would see on an engine block.

What concerned us more than anything is knowing that the design of an elastomer style damper is very critical to how well the material is bonded between the inner and outer ring. This must be able to withstand the constant oscillation and heat for many years. The elastomer must be made of a material that won't dry out any time soon.

One more very important aspect of this material is its Durometer rating. The Durometer rating, or resilience, is very important, as it should be in tune with the crank harmonics or it will not be able to do its job properly. Knowing how much pride the Pro Race company takes in everything they make, we are confident this factor has been addressed.

When we're standing over an engine to set the timing, we usually have to rev the engine up to around 4000 rpm or more to make sure we get a total timing reading, as most distributors have very resistant springs in them. I would not want to think that I sold a damper that could develop a fracture or already have one in it, and know that this could break under high rpm, and whoever is standing above it would be at risk of death or serious injury.

As we mentioned, stay away from the no name, or ultra low cost dampers. A final note: get rid of that tired old damper on your engine. The elastomer ring is more than dried out, and is most likely not dampening the damaging crank harmonics. This can lead to fractures in the crankshaft. It is claimed that dampers that are not doing their job can cost horsepower. This is most likely due to the fact that the crank harmonics are not being dampened, and create a drag in the engine.

Harmonic Balancer, Crankshaft Harmonic Damper, Torsional Vibration Damper.

The term so often used for this component is harmonic balancer, which suggests the unit balances the engine. In general, this statement is misleading. A better description for this component is a harmonic damper or torsional vibration damper. This better describes the actual function of the unit.

Torsional vibration occurs in the crankshaft of engines, as a result of the combustion process, the sudden reversal of load on the piston, connecting rod and crankshaft during compression, followed by the ignition or firing of the compressed fuel and air in the combustion chamber. Subsequent relaxation of the load following combustion causes deflection or flexing of the crankshaft. This oscillating vibration which results from the reciprocating load changes will remain in force until dissipated by internal friction or damping. At certain RPM ranges these oscillations can come into phase with each other, creating potentially damaging torsional peaks in the crankshaft.

Unless the amplitude of these torsional vibrations is controlled, major damage can occur to engine components, such as rapid wear of the timing sprockets, stretching or breakage of the timing chain, pitting or cupping of the camshaft and lifters, broken valve springs and valve train failure, reduced service life of crankshaft bearings. In extreme situations uncontrolled torsional vibrations can lead to a loose flywheel or a broken crankshaft with serious safety consequences.

Why use a tuned elastomer (rubber) damper.

Elastomer harmonic dampers have been used exclusively by Automotive OEMs for car engines, no matter what brand of vehicle, be it local or imported. The reason is simple, they have found that a tuned elastomer damper is able to reduce destroying crankshaft harmonics more effectively and over a wider range of RPMs than other styles of dampers.

PRO/RACE, PRO/SPORT and PRO/STREET tuned elastomer dampers are also marketed as private label models by Ford Racing, Mopar Performance and others. These groups tested a number of aftermarket dampers including fluid or viscous style dampers prior to selecting PRO/RACE and PRO/SPORT tuned elastomer dampers which provide superior dampening for rapidly accelerating, high RPM engines.