What does a harmonic balancer do?

A harmonic balancer, also known as a crankshaft damper, absorbs torsional vibrations from the crankshaft. These vibrations are a natural byproduct of an engine's combustion cycle and can cause wear and damage to the crankshaft and other engine components over time.

How do I know if my engine is internally balanced?

For Pontiac V8s, engines like the 389, 400, 421, 428, and 455 CID are typically internally balanced. However, it's always best to confirm with your specific engine's service manual or by inspecting the crankshaft snout and flywheel/flexplate for balance weights.

Does this harmonic balancer come with any hardware?

This harmonic balancer is sold individually and does not include installation hardware such as bolts or pulleys. You will typically reuse your original hardware or source it separately based on your specific application's requirements.

Fluidampr Pontiac 389 400 421 428 455 CID V-8 Steel Internally Balanced Damper

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Specifications

Brand: Fluidampr
Part #: 650401
UPC: 00815293001180

Fluidampr Pontiac 389 400 421 428 455 CID V-8 Steel Internally Balanced Damper

Name: Fluidampr Pontiac 389 400 421 428 455 CID V-8 Steel Internally Balanced Damper
Brand: Fluidampr
Price: 588.62 USD
Availability: InStock

$588.62

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Fluidampr steel harmonic balancer for Pontiac 389-455 CID V8 engines. Controls torsional vibration across the entire RPM range to protect your engine.

Key Features

Fits 1959-1979 Pontiac, Oldsmobile, and Buick V8 engines with internal balance.
Controls harmful torsional vibrations across the entire RPM range for improved engine durability.
Reduces wear on critical engine components and lowers the risk of crankshaft failure.
Precision CNC machined and balanced from high-grade steel with a black zinc corrosion-resistant finish.
Features engraved timing marks for straightforward installation.
SFI 18.1 certified and race-proven for over 35 years.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Will this fit your vehicle?

Product Details

If you're working on a Pontiac, Oldsmobile, or Buick V8 with an internally balanced crankshaft, this Fluidampr harmonic balancer is a serious upgrade over stock. Modifications, especially to the engine's breathing or fuel system, can create torsional vibrations that the factory balancer wasn't designed to handle. This Fluidampr unit is built to control those harmful vibrations across the entire RPM range, from idle all the way up to redline. By taming these vibrations, you're not just protecting your engine; you're reducing wear on critical components like the crankshaft and bearings, which can prevent costly failures down the road. It can also lead to improved ignition timing accuracy and help unlock some of the torque and horsepower that might otherwise be lost to vibration.

This balancer is precision CNC machined from high-grade steel and features a viscous damper design that's been race-proven for over 35 years. It has a durable black zinc corrosion-resistant finish and includes engraved timing marks for easy installation. Unlike some other types of dampers, this Fluidampr unit requires no maintenance over its lifespan. It meets the SFI 18.1 specification, making it suitable for high-performance applications and racing. It's a well-built component trusted by many engine builders for its effectiveness in protecting and enhancing engine performance.

This harmonic balancer fits a wide range of Pontiac, Oldsmobile, and Buick V8 engines from the late 1950s through the late 1970s, including popular models like the Pontiac Bonneville, Firebird, and Grand Prix. It's designed for internally balanced engines, so be sure to check your specific application. It comes ready to install and requires no ongoing maintenance, offering long-term protection and performance benefits for your classic V8.