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Fluidampr Harmonic Dampers 650401 Balancer, Internal Balance, Steel, Black, Pontiac, V8, Each

SKU: FDR650401

Harmonic Balancers

FDR Dampers - Domestic...

Fluidampr Harmonic Dampers 650401 Balancer, Internal Balance, Steel, Black, Pontiac, V8, Each

SKU: FDR650401

Harmonic Balancers

FDR Dampers - Domestic...

A$1,171.75
BACKORDER This item will be special ordered in for you. Contact us prior to purchase if you require an ETA.

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Description

Harmonic Balancer - 6.625 in OD - Steel - Black Zinc - Internal Balance - Pontiac V8 - Each

Harmonic Balancer

Protect your engine. Modifications can compromise your stock harmonic balancer. Install a Fluidampr performance damper early for best durability. Superior viscous damper design controls harmful torsional vibration across the entire rpm range. Reduce wear on engine components. Reduce risk of crankshaft failure. Improve timing. Unleash lost torque and horsepower. Precision CNC machined and balanced high-grade steel components. Corrosion resistant black zinc finish with engraved timing marks. No maintenance required. Trusted by leading engine builders worldwide. SFI 18.1 certified. Made in USA.

Additional Information

Harmonic Balancer - Fluidampr - Pontiac / Oldsmobile - 1959 - 1979 V8 - Internal Balance - Steel - Black Zinc Chromate - 6-5/8" dia - 10.2 lbs - SFI 18.1 - Made in USA - Each

Application Summary

1959-1979 Pontiac / Oldsmobile. 326, 389, 400, 421, 428, 455 V8. Internal balance. 4 bolt pulley pattern on 3.300 bolt circle. Holes in pulley must be re-drilled, '69-later timing cover and pulley may be required on early models.

Part Type

Engine Harmonic Balancer

Product Overview

Fluidampr Engine Dampers are designed to control destructive vibrations which are transfered thru the crankshaft.

Each time the air/fuel mixture inside a cylinder is ignited, the combustion that occurs creates a torque spike that is applied to the crankshaft through the piston and rod. This torque spike is so severe that it not only turns the crankshaft, it actually twists the crankshaft ahead of its normal rotation and then the crankshaft rebounds. This twisting action is known as torsional vibration. When these torque spikes and forces get into phase with the natural frequency, critical torsional harmonic vibrations occur and can be seriously destructive to the bearings and the crankshaft. Dampers are designed to control those destructive vibrations.

Critical harmonic vibrations occur numerous times in a engine's operating range. Stock rubber and elastomer-type dampers are frequency sensitive “tuned absorbers”, and work at only one critical frequency. In the case of a stock rubber damper, it is tuned for a factory engine's critical harmonic vibrations. If you change the mass of pistons, rods, or the crankshaft, you change the natural frequency of the crankshaft assembly; therefore, the stock damper is no longer tuned to the new frequency of vibration, and you may be headed for early failure of expensive engine components. Dampers also create heat while they work, and rubber is a poor dissipator of heat. This heat and the exposure to the elements deteriorates rubber, causing it to crack and change durometer, which then leads to inertia ring slippage, damper failure, uncontrolled torsional vibration, and costly engine parts breakage.

Additional Application Notes
• WT. in lbs.()=Rotating weight: 10.4 (7.0 Rwt) Safety Rating: SFI 18.1 O.D.: 6-5/8" (6.625) Mounting Hardware Incl.: No Material: Steel Length: 2.837 Keyway: Single Finish: Black Zinc Engine Balance: Internal Degree Markings: Yes Degree Marking Range: 50 BTDC to 10 ATDC. Additional timing/degree marks at 90, 180 and 270 Bore Dia. Min/Max: 1.3722 / 1.3732 4 bolt pattern on 3.300 circle. Holes in pulley must be re-drilled. '69-later timing cover & pulleys may be required on Early Models.

These additional application notes are supplied by the manufacturer and collated from multiple year ranges. Not all of these notes may apply to every year or every variant. Please contact a StreetFX agent for clarification if required.

Data: v4.2 - Upd: 2026-11-08 07:31:31

Features

Made in USA.

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Specifications

Product Details

Bolt and Washer Included:No
Bore Dia. Min/Max:1.3722 / 1.3732
Degree Marking Range:50 BTDC to 10 ATDC. Additional timing/degree marks at 90, 180 and 270
Degree Markings:Engraved
Depth:3.247
Description:Fluidampr Harmonic Balancer
Engine Balance:Internal
Finish:Black Zinc
Grade Type:Performance
Inside Diameter:1.372
Keyway Spec:Single; (3/16")
Keyway Type:Yes
Keyway:Single
Length:2.837
Material:Steel
Mounting Hardware Incl.:No
Mounting Hole Diameter:1.372
Mounting Hole Quantity:1
O.D.:6-5/8" (6.625)
Outside Diameter:6.625
Part Number:fdr650401
Pulley Bolt Pattern:4 bolt pattern on 3.300 circle. Holes in pulley must be re-drilled. 1969-later timing cover and pulley may be required on earlier models.
Safety Rating:SFI 18.1
TITLE:Fluidampr - 650401 - Harmonic Balancer - Fluidampr - Pontiac / Oldsmobile - V8 - Int Balance - Each
WT. in lbs.()=Rotating weight:10.4 (7.0 Rwt)
Weight / Rotating Weight:10.2 lbs / 6.8 lbs

Product Downloads

# Document Type Download
1. Installation Instructions

Installation guides, warranty details, and other supporting documents are provided by the supplier. In some cases, these files may originate from regions outside your locale, meaning instructions, warranty procedures, and images may not fully align with your specific vehicle or region (e.g., LHD vs. RHD differences, return policies, etc.). If you need clarification, please contact a StreetFX support agent.

Data: v2 - Desc: v4.2 - Upd: 2026-11-08 01:11:39

Reference Information

Reference Data (Provide these details to our support team)
Brand Name/s Fluidampr, Fluidamper
StreetFX SKU fdr650401
SFX Item ID 4403616
Accounting SKU fdr-650401
Manufacturer SKU 650401
Manufacturer UPC 00815293001180
Alternative References 650401, FLU-650401, FLU650401

Harmonic Balancer, Internal Balance, Steel, Black, Pontiac, V8, Each

Using only three parts (a laser-welded sealed housing, an internal inertia ring, and highly viscous silicone fluid between the two), SFI-approved Fluidampr harmonic dampers can control all crankshaft vibration--not just a limited frequency range. As a result, you get reduced wear on the main bearings and timing gear, more stable valvetrain operation, and less chance of crank failure.

Product Attributes
BrandFluidampr
Manufacturer's Part Number650401
Part TypeHarmonic Balancers
Product LineFluidampr Harmonic Dampers
UPC815293001180
Engine BalanceInternal
SFI RatingSFI 18.1
Degree MarkingsYes
Degree Marking Range50 BTDC to 10 ATDC
Outside Diameter (in.)6.625
Crankshaft Pulley Bolt Hole QuantityFour
Keyway QuantityOne
Harmonic Balancer MaterialSteel
Harmonic Balancer ConstructionFluid
Harmonic Balancer ColorBlack zinc chromate
Mounting Hardware IncludedNo
QuantitySold individually.
NotesAdditional timing/degree marks at 90, 180, and 270 degrees.

Manufacturer Attributes
Bolt and Washer Included No
Outside Diameter 6-5/8"
Title Fluidampr - 650401 - Harmonic Balancer - Fluidampr - Pontiac / Oldsmobile - V8 - Int Balance - Each
Safety Rating SFI 18.1
Pulley Bolt Pattern 4 bolt pattern on 3.300 circle. Holes in pulley must be re-drilled. 1969-later timing cover and pulley may be required on earlier models.
Mounting Hole Quantity 1
Degree Marking Range 50 BTDC to 10 ATDC. Additional timing/degree marks at 90, 180 and 270
Material Steel
Keyway Type Single; (3/16")
Inside Diameter 1.372
Finish Black Zinc
Engine Balance Internal
Depth 3.247
Degree Markings Engraved
Weight / Rotating Weight 10.2 lbs / 6.8 lbs
Manufacturer Designation Harmonic Balancer - Fluidampr - Pontiac / Oldsmobile - V8 - Int Balance - Each
Product Class Engine Harmonic Balancer
Construction/Type Harmonic Balancer - Fluidampr - Pontiac / Oldsmobile - 1959 - 1979 V8 - Internal Balance - Steel - Black Zinc Chromate - 6-5/8" dia - 10.2 lbs - SFI 18.1 - Made in USA - Each
Vehicle Designations 1959-1979 Pontiac / Oldsmobile. 326, 389, 400, 421, 428, 455 V8. Internal balance. 4 bolt pulley pattern on 3.300 bolt circle. Holes in pulley must be re-drilled, '69-later timing cover and pulley may be required on early models.
Product Outline Broad RPM range protection.
Reduce risk of crankshaft failure.
Reduce wear on critical engine parts.
Unleash lost torque & horsepower.
No maintenance required.
Superior durability.
SFI 18.1 spec. Race proven for over 35 years.
Made in USA.
Vehicle Brief Fluidampr Performance Damper
Market Description Protect your engine. Modifications can compromise your stock harmonic balancer. Install a Fluidampr performance damper early for best durability. Superior viscous damper design controls harmful torsional vibration across the entire rpm range. Reduce wear on engine components. Reduce risk of crankshaft failure. Improve timing. Unleash lost torque and horsepower. Precision CNC machined and balanced high-grade steel components. Corrosion resistant black zinc finish with engraved timing marks. No maintenance required. Trusted by leading engine builders worldwide. SFI 18.1 certified. Made in USA.

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