Balancers and Pulleys

Chevy Small-Block V8 | Balancers and Pulleys

BAD VIBRATIONS An effective torsional damper will extend the life of your small-block V8 for V6/90-degree Chevrolet by dampening harmful crankshaft vibrations. The torque inputs from the piston and rod assemblies bend and twist the crankshaft slightly with every power stroke. The crank then rebounds as the next cylinder fires. A torsional damper "quiets" these potentially destructive vibrations. Productoin Chevrolet torsional dampers control crankshaft vibrations by the stretch and rebound of an elastomer (synthetic rubber) ring sandwiched between the damper's hub and its outer inertia ring. The GM/Fluidampers, in contrast, dampen vibrations by shearing a thick, viscous silicone fluid which is sealed inside the damper housing. Elastomer balancers are tuned to a specific frequency, and are very effective at that frequency. The GM Fluidamper is not tuned to a specific vibration frequency, so it is effective over a wide range of operating needs.


10051170	GM/Fluidamper (7.25" diameter)
This 7.25" diameter damper uses a viscous fluid to control destructive crankshaft vibrations instead of an elastomer ring. The GM/Fluidamper's inertia ring and fluid are contained inside a laser-welded, hermetically sealed housing. Differences in the rotational speed of the housing and the inertia ring dampen crankshaft harmonics by shearing the silicone fluid. Unlike a conventional torsional damper, the GM/Fluidamper is not tuned to a specific vibration frequency; its performance is not affected by changes in the weight of the engine's crankshaft assembly. Errors in spark timing caused by movement of the outer ring on a conventional damper are eliminated. The GM/Fluidamper requires no periodic maintenance. The viscous silicone fluid is unaffected by heat. The outer housing has contrasting timing marks from 50º before Top Dead Center to TDC. This balancer meets SFI 18-1 specifications, and is accepted for competition by NHRA and other racing sanctioning bodies.
Technical Notes: This damper is neutral balanced; do not use with externally balanced 3.75": stroke crankshafts. Timing pointers are not available for 7.25" OD balancers; modify pointer P/N 12341915 to fit this damper. Damper weight is 13.4 pounds.


10128489	Torsional Damper, LT1
This damper is used on all 1992-97 LT1 engines.
Technical Notes: This balancer bolts onto a balancer hub, P/N 12553250 for 1992-95 models and P/N 12550097 on 1996-97 models.


12341632	GM/Fluidamper (6.25" diameter)
This smaller diameter version of the performance-proven GM/Fluidamper is ideal for applications which require a lightweight harmonic damper, and for engine compartments with limited space. It has the same advanced engineering features as the 7.25" diameter GM/Fluidamper P/N 10051170, including a laser-welded sealed housing, a free-floating internal inertia ring, and a viscous silicone fluid that is unaffected by heat.
Technical Notes: The 6.25" diameter GM/Fluidamper weighs 7.9 pounds. If damper performance and engine protection is the most important consideration, the 7.25" diameter GM/Fluidamper (P/N 10051170) is recommended; if light weight is a priority, or if there are space limitations, this smaller diameter GM/Fluidamper is recommended. Dyno and track tests have shown that the 6.25" diameter GM/Fluidamper will outperform comparably sized production elastomer dampers. This damper is neutral balanced; do not use with externally balanced 3.75" stroke crankshafts. Timing pointers are not available for 6.25" diameter dampers; pointer P/N 12342000 can be modified to fit this damper.


12367601	Timing Tape, Balancer
This balancer tape is used on special LT4 crate engine P/N 12371172. It can also be used on any 8-inch balancer.



12550097	Hub, Crankshaft
This hub is used on all LT4 engines, and all 1996-97 LT1 engines only.



12551486	Torsional Damper, LT4
This damper is used an all LT4 engines
Technical Notes: This balancer bolts onto a balancer hub, P/N 12550097.


12553250	Hub, Crankshaft
This hub is used on all 1993-95 LT1 engines only.



12555879	8" Torsional Damper
Originally used on 1970-74 350ci LT-1, Z-28, and L-82. This cast iron balancer's inertia ring is 111/16" wide; it has the 1969 and later timing mark. This damper is used on all ZZ4 engines.
Technical Notes: Use with chromed timing pointer P/N 12341915.


14001829	Washer
13/4" OD x 1/2" ID x 5/16" thick.



24502534	Torsional Damper - Standard Hub
These dampers are specially tuned by GM engineering for up to 9000 rpm usage. They are used on all small-block V8 engines with standard size crankshaft hub diameter. These dampers employ 70 durometer O-rings to dampen harmful crankshaft vibrations. The black outer ring is fully degreed with contrasting white marks to simplify ignition timing and valve lash adjustments. The hub is drilled and tapped for standard pulleys and accessory drives. The dampers are 7.74" in diameter and weigh 8.95 pounds (4.5 pounds intertia weight).



24502535	Torsional Damper - Large Hub
These dampers are the same as P/N 24502534 except that they are used with a large diameter crankshaft nose (dia. 1.598). This is the same as Chevrolet big-block hub size.



364709	Heavy-Duty 8" Torsional Damper
This off-highway damper is designed for competition small-block V8s in racing classes which permit the use of production-type balancers. Its nodular iron inertia ring offers an extra margin of reliability at high rpm. High temperature rubber is used between the hub and inertia ring to improve durability. The hub is balanced separately before the damper assembly is balanced as a unit. This heavy-duty damper is ID #4709; its outer ring is marked "MALL." The timing mark is 10º before keyway center line.
Technical Notes: Use with chromed timing pointer P/N 12341915. See the Chevy Power manual for recommended damper preparation procedures.


3815933	Crankshaft Bolt
This 7/16-20 x 21/4" bolt positively retains the balancer and pulley on the crankshaft snout. For all small-block V8s and V6/90º engines with tapped crank snouts.
Technical Notes: Use with washer P/N 14001829.


3817173	8" Torsional Damper
This damper was originally used on high-performance 302 and 327ci small-blocks produced from 1962-68. Its cast iron inertia ring is 111/16" wide. Damper ID #7173. The timing mark is 2º before keyway center line.
Technical Notes: This damper has the pre-1969 timing mark location. Do not use with chromed timing pointer P/N 12342011 unless TDC mark is adjusted.


3858533	Crankshaft Pulley
This 65/8" diameter crankshaft pulley was originally installed on high-performance 1962-68 302 and 327ci V8s. Its two deep grooves are designed to retain the fan belts at high rpm. This pulley fits small-block V8 and V6/90º engines with short water pumps. ID #3766987.
Technical Notes: Can be used with water pump pulley P/N 3770245 and captured belt P/N 9433722 without an idler pulley or alternator.


6272221	6.75" Torsional Damper
This cast iron torsional damper (harmonic balancer) is used on most 1969 and later production 305 and 350ci small-block V8s. It is recommended for V6/90º racing engines and V8 applications with limited clearance. 6.75" diameter balancers have also been used successfully on drag racing small-blocks in classes which permit the use of cast iron dampers. The timing mark is 10º before keyway center line.
Technical Notes: Use with chromed timing pointer P/N 12342000.


6272225	8" Torsional Damper (400ci Small-Block)
The 400ci small-block's externally balanced crankshaft requires this counterweighted 8" diameter balancer, automatic transmission flexplate P/N 471578 or manual transmission flywheel P/N 3986394 for proper engine balance. The timing mark is 10 degrees before keyway center line.
Technical Notes: Can be used with chromed timing pointer P/N 12341915.