When the cylinders fire, torque is imparted to the crankshaft via the connecting rod causing energy to be dispersed through the engine. The front of the crankshaft takes the brunt of this power, so it often moves before the back of the crankshaft. The crankshaft deflects under this applied torque and harmonic vibrations are induced when the torque is released.

At certain engine rpms the torque is in synch with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance can cause stress resulting in crankshaft failure.

To reduce this this vibration the harmonic balancer is attached to the front part of the crankshaft and consists of three parts. The inner part is bolted directly onto the crankshaft itself. The centre part is a dampening material (usually a rubber ring) which is used to dampen the crankshaft vibrations, and the outer part has the timing marks and pulley cuts in it for the belts. When the crankshaft tries to twist the rubber absorbs the energy preventing the crankshaft from breaking.

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Buy harmonic balancers in Australia and the USA here

Australia Powerbond dampers

VY V6 S/Charged Powerbond Overdrive Performance Pulley

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USA Powerbond dampers

Edelbrock 9359 Powerbond Self Sealing Hose Wrap

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Powerbond harmonic balancers
The POWERBOND Street Harmonic Balancer Series brings bonded balancer technology within the budget of every performance street engine builder from mild to wild. They also make a great heavy duty standard replacement balancer.

POWERBOND Street Balancers are also perfect for limited spec race classes such as late model stock that require an OEM style balancer.

The bonded dampening rubber in every POWERBOND Street Series balancer eliminates spinning and component separation giving reliable performance in engines used to 6500rpm.

POWERBOND Street Series combine new high strength SG (Nodular) Iron balancer centres with new inertia rings, bonded then balanced to extremely tight tolerances.

POWERBOND Street balancers feature easy to read permanently etched timing marks on the outer ring.

SFI Race Powerbond Balancers
The POWERBOND Race Series brings the advantages of bonded balancers to high revving race and street/race applications where an SFI approved balancer is required.

Every Race Series POWERBOND balancer features a precision CNC machined AUSI 1045 steel centre bonded to an equally strong steel inertia ring. Advanced design means that Race Series balancers are very light for an all steel product. In most cases they are only marginally heavier than the original cast iron balancer and generally much lighter than other all steel balancers on the market. The steel inertia ring of the Race Series models is positively protected against forward and backward movement and has the assurance of bonded rubber to eliminate spinning.

Every model has easy to read SERPENTINE Late model engines with Serpentine belts driven off the damper ring create much higher loads on both the inertia ring and dampening material. The strength and durability of POWERBOND is even more critical on Serpentine engines particularly in performance or race applications.

POWERBOND Serpentine dampers are available for popular late model applications including Chev LT1, LS1 and LS6 and the Ford 4.6 and 5.4 litre Modular series. To give engine builders maximum flexibility, Street and SFI Race versions are available.

In addition Race versions are offered in standard diameter, 10% underdrive, 25% underdrive and 8 rib drive for supercharger conversions balanced to extremely tight tolerances.

POWERBOND Street balancers feature easy to read permanently etched timing marks on the outer ring. Every model has easy to read computer etched timing marks.

All POWERBOND Race series balancers meet SFI specification 18.1.

Powerbond Balancer Dampening Material
All POWERBOND dampers use a rubber formula that has been developed over 23 years in the damper business. The formula is exceptionally resistant to ageing and gives excellent control of elasticity in the pressure bonding process employed.

Pressure Bonding – The most time consuming and secure method of damper assembly used by prestige and performance carmakers such as Mercedes Benz, BMW and Porsche. Damper components are chemically primed and assembled in highly accurate pre-heated steel press dies. Specifically formulated rubber is injected into purpose built 100 ton bonding presses and cured in the mould until optimum strength is achieved. This method gives unrivalled rubber to metal bonding strength, resistance to ring dislocation and control of rubber duro or elasticity. All POWERBOND dampers are assembled using state of the art pressure bonding methods.

Metallurgy
Street Powerbond Harmonic Balancers
OEM Style dampers are usually manufactured from cast iron. Not all cast iron is created equal and to save cost some aftermarket balancers use regular “grey” cast iron which has limited strength and is prone to cracking.

All POWERBOND STREET series dampers are manufactured exclusively from high strength S.G. iron (also known as nodular iron) which is the same material used in most crankshafts. This high-grade iron has much greater resistance to cracking than the cheaper grey iron.

Race Powerbond Harmonic Balancers
POWERBOND RACE dampers are manufactured from solid billet steel bar stock to AUS 1045 specification. Steel is stronger and more wear resistant than aluminium alloy used in some products. Wear resistance is critical in the oil seal and crank nose areas. Whilst alloy is a lighter base material careful design of the damper can minimize the weight variance when using the stronger steel base material.

You can view the Powerbond harmonic balancer application guide here.