how to tell which small block chevy damper is designed for your engine

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
THE FIRST THING I'D POINT OUT IS THAT YOU CAN GO GUESSING YOU NEED TO DEAL IN VERIFIED FACTS
step one is verifying TDC and degreeing in your cam correctly


CrankltHub.jpg
LtHub.jpg

lt1hubv.png

https://www.nookandtranny.com/Info_LT1.html
http://garage.grumpysperformance.com/index.php?threads/finding-top-dead-center.967/

http://garage.grumpysperformance.co...ter-1-for-timing-ignition-cam.966/#post-18999

http://garage.grumpysperformance.co...ectly-and-get-it-to-last-cam-install-info.90/

DETAILS AND INFO IN these threads might help
step two

once you have the cam properly degreed in,and you've verified true TDC. your timing tab should indicate exactly where TDC on the timing tab and damper will be located and match the two locations, with the verified true TDC, youve previously verified

I,ve generally found that if you've stripped the SBC crank snout threads the best answer is to drill and re-thread to the standard and larger BBC crank snout bolt threads size

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worn balancer shaft too oil seals can cause leaks, there are repair sleeves available
https://www.summitracing.com/parts/fel-16202/overview/



There are two different COMMON TDC marks on small-block dampers, depending on the age of the damper.
Pre-1969 dampers (top) place the TDC mark at 2 degrees before the keyway,
while 1969-and-later dampers (bottom) place the TDC mark at 10 degrees before the keyway

I found this info posted several places

The three most common locations for the timing mark on the damper

The exact years of the type of damper timing marks overlap one another, depending on the exact application.

The pre-1969 damper has the TDC line on the outer ring at the 2:30 o’clock position- or 2º before the keyway centerline- i.e. the line is to the LEFT of the keyway, looking at the front of the damper or engine. The keyway is seen in the ID of the damper nose.
The damper used from 1969 to about 1984 has the TDC line at the 2 o’clock position- or 10º before the keyway. You'll find that aftermarket dampers are the 10º type, as are the bolt-on tabs sold by the aftermarket, unless they're adjustable.
Warning Note: This includes the SBC 400, although the 400 damper is counterweighted because the engine is externally balanced. Do not mix and match internal and external balanced dampers!
A third timing mark was used from (some) 1978 to about 1995, and nearly all 1984-1995. It is at the 12 o’clock position- or 40º before the keyway. This damper uses a timing cover that has the tab welded on at about the 12 o'clock position. Professional Products lists the years for this type damper line as being 1984-1995 and is a 6-3/4” diameter damper.

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WHEN CRANK IS AT TWELVE AND CAM IS AT SIX THEN #6 CYL IS FIRING AFTER YOU LINE UP YOUR MARKS AND INSTALL GEAR THEN ROTATE YOUR CRANK ONE REVOLUTION AND THEN DROP THE DIST. IN - AT THAT POINT
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KEEP IN MIND that theres TWO totally different damper and timing tab locations that are correct on the SBC engines and you must use matched components for almost all years the ting tabs and dampers show TDC to be at about 2 o,clock, but theres a few applications that used a 12 o,clock timing tab and damper combo and you can,t mix&match the two types

youll be better off if you USE A DEGREE WHEEL AND PISTON STOP, & verify rather than GUESS, so verify TDC on your engine and the damper markings and timing tab you select reflect reality rather than just assuming the parts you choose are correct because the guys selling them assured you they fit!
http://garage.grumpysperformance.com/index.php?threads/finding-top-dead-center.967/

http://garage.grumpysperformance.co...ter-1-for-timing-ignition-cam.966/#post-18999
use the correct damper instal tool NEVER beat a damper with a hammer
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ctrp-1211-quality-damper-installation-shock-absorber-07.jpg


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http://www.amazon.com/OTC-4531-Harmonic-Balancer-Installer/dp/B000F5LIW4/?tag=viglink22466-20
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Engine Balance: Internal vs. External
An engine must be balanced to ensure smooth operation. It minimizes vibration and maximizes engine life. Balancing can be internal, external, or a combination of both.

Balancing an engine means offsetting the weight of the pistons and rods. This involves adding or removing weight from the crankshaft. The Harmonic Balancer and/or the flexplate or flywheel can also be weighted.

Internal Balance
An internally balanced engine has all the counterweight on the crank. External parts like the balancer and flexplate/flywheel have a neutral balance. They will not affect the other rotating parts.

External Balance
If the crank's counterweights are too light, the engine must be externally balanced. This involves adding weight to the harmonic balancer and/or the flexplate or flywheel.

How does it affect performance?
Generally speaking, internal balance is the better option. External counterweights can cause the crankshaft to flex at high rpm. This can cause engine damage. However, either type of balance is fine for most engines.

Converting from external to internal balance can be expensive. It requires a new crankshaft, harmonic balancer, and/or flywheel or flexplate. You may also need to clearance the block for the larger counterweights. Unless you're racing, it's easiest to balance the engine the same way the factory did.

Engine Type Factory Balance Method
Chevy 305/350 (2-piece rear main seal) Internal
Chevy 396-427 Big Blocks
Chevy LS Engines
Ford Modular Engines
Chevy 400/454 External
Ford 302/351W
Chevy 350 (1-piece rear main seal, including LT1) Combination of Internal & External


Notes
Balanced Rotating Assemblies come pre-balanced from the manufacturer. These can be installed without taking the parts to the machine shop.

If you buy an Unbalanced Rotating Kit, you will need to have it balanced before it's installed. The same is true if you buy a crankshaft, connecting rods, and pistons separately.

Crankshafts are listed as internal or external balance. This doesn't mean it's already balanced. It just tells you how it's intended to be balanced. It must be checked with the specific piston and rod combination you use.

http://www.jegs.com/p/ATI/ATI-Super-Dam ... 7/10002/-1
MOST NASCAR TEAMS USE ATI DAMPERS AND THEY CERTAINLY HAVE THE TEST DATA TO SUPPORT THE CHOICE

the stock TYPE balancer has a rubber ring glued between the inner hub and outer inertial ring and yes they do deteriorate over time and have been known to slip, especially if subjected to being oil soaked over time, or someone used a hammer vs the correct tool to get it back on the crank
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worn balancer shaft too oil seals can cause leaks, there are repair sleeves available
https://www.summitracing.com/parts/fel-16202/overview/
READ SUB LINKS they contain more info youll need
http://garage.grumpysperformance.com/index.php?threads/harmonic-balancer.3554/#post-13385

http://www.hotrod.com/how-to/engine/hrdp-1009-6-or-8-inch-balancer-for-small-block-chevys/

http://www.summitracing.com/search/section/harmonic-balancers/make/chevrolet

http://garage.grumpysperformance.com/index.php?threads/timing-tabs-and-indicators.1015/#post-32912

models916 said:
The bolt will work if you start out with a longer bolt and then transition to the shorter one. In the old days, before the crank was threaded, GM called for a big hammer to install the thing.

while thats true in most cases, if its only done a few times and your very selective about the thread engagement, its also true that using the bolt to pull the damper into place frequently causes problems,
FACT bolt threads must have about 1.5 times the diameter of the bolt threads fully engaged too equal max tensil strength, any less length of threads engaged significantly reduces the resistance of the threads to strip out under tension.
look at the two bolts below, the upper GRADE #8 ARP bolts stronger but with a minimum of 1.5 times its thread diameter already threaded into a crank snout ,too reduce the chance of stripping threads how much farther can it be screwed in, to pull the damper in place before the threads bottom out?


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if the threads bottom out and you applie torque shearing off the bolt or stripping the threads in the crank is a common result
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using a bolt and a washer to draw on a damper can occasionally allow a slightly out of alignment or cocked damper to bind on the crank snout this frequently results in stripped threads a sheared bolt or a broken damper
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CrankltHub.jpg
LtHub.jpg

lt1hubv.png

https://www.nookandtranny.com/Info_LT1.html
If your going to re-use it ,Id suggest having a machine shop inspect it for deterioration, of its elastomer ring and the machine shop will need to check it for cracks,and a loose or defective rubber ring binding the inner and outer hubs, provided its only going to be used on an engine used for daily transportation.
theres hundreds of thousands of old O.E.M. balancer's being used on street car engines and failures are not that common in street use, but once you start running the engines up above about 5000rpms the stress increases and that ring tends to over time degrade and fail,
chances are good that the elastomer is worn or starting to deteriorate after 30 years,

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beating on a damper with a hammer will frequently induce stress cracks that can and do eventually result in crank shaft or thrust bearing failures, these may not become apparent for tens of thousands of miles but are there none the less and should be avoided
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OBVIOUSLY a machine shop doing balancing work on a rotating assembly's , and adding mallory metal slugs to counter weights,on the crank must do quality work or problems with durability usually result that get damn expensive or dangerous
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[quote-
Indycars]
Since I'm going to be replacing the damper bolt with the bigger BBC component, I'm also going
to upgrade the balancer while I'm there.

I'm trying to decide if the gold Race Series dampers is any better than the black Streetdampers ....
without the consideration of money.

I found the below info on the Fluidampr website.

http://www.fluidampr.com/what/

Fluidampr Dampers Performance over 6,000 RPM

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the damper is engineered to allow for quick acceleration and the rapid increase in torsional vibration frequency associated with higher rpms. There is a clerical difference between “meets SFI standards” and “SFI certified”. The former means we construct our Streetdampers to the same rigorous standards as those that are SFI Certified. The later means, we have worked diligently with SFI Foundation Inc., who sets the rules and regulations for most racing organizations, to have our Race Series dampers independently tested, officially certified and regularly scrutinized by SFI. SFI Certified is a very scientific and costly endeavor to ensure that the construction of our product will hold up in the racing world. Regardless of terminology, the engine owner wins because our Streetdampr are manufactured to the same high level race quality outlined by the SFI Foundation Inc.


I found this, but it's still not conclusive about which damper would be better.

http://www.enginelabs.com/engine-tech/engine-harmonics/ati-fluidampr-tci-offer-expert-damper-advice/

LeBarron: Fluidampr offers a value-priced line of non-SFI rated Streetdampr brand dampers for popular small block Chevy and Ford applications. Streetdampr products can be used from mild to heavily modified applications whenever SFI 18.1 specs are not required because they provide similar benefits of broad range protection coverage and superior durability as Fluidampr just without a final protective finish. With some select applications we also offer different diameters and weights. It’s a compromise; a larger, heavier damper will provide more damping but slower throttle response and a smaller, lighter damper will improve throttle response but provide less protection. It is always best to consult with your engine builder or damper manufacturer if you need assistance.

https://www.summitracing.com/parts/flu-620101
https://www.summitracing.com/parts/flu-62260d/overview/


Any Opinions ??? Which one would be better ???

If I was making the choice ID call fluidamprs tech line and ask....
several questions ,
simply because
if your not sure its simply that you don,t have enough facts,
to make a logical fact based decision.


For Technical Support and Product Information Call or E-mail us at:
Phone:
(716) 592-1000
Email: sales@fluidampr.com
Office Hours:M - Fr 8:00am - 4:30pm EST.
If after hours, please leave a message and we will get back to you as soon as possible.

https://www.summitracing.com/parts/flu-62260d/overview/
but ID certainly be looking harder at the gold version simply because it looks like theres,
been a few minor improvements made and the cost difference is insignificant in the long term
be aware theres internal and externally balanced damper and several diameters from about 6.25", 7" and 8" so ask pointed detailed questions, and know what you need.
 
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