Hi guys, am building up a small block stroker for street use.
Have a chance to get a slightly used fluid damper.
From the little bit of internet reading I have done, I get the impression these fluid dampers are not very desireable.
Is this something I should stay away from or not? Thanks for any info.

IF it's a real Fluidampr, it's a good thing. This is the technology used to dampen vibrations in crankshafts of very large and expensive engines.
Real Fluidamprs are expensive.

Real ones are built in the USA.

Fake fluid dampers may or may not work, but I'd suggest something else first.

R.

I tried one on a 440 but it wouldn't align with my pulley set up.

I have a FluidDampr from 1995, virgin. Never been run. I have it set aside for my 505. The guy at the machine shop said there isn't a problem when I bored the block 4 yrs ago..I think the new design, with a name that isn't original is going to cause issues..

I like the fluid dampers (brand name) but one thing to be very aware of it must be tight fit!! Nice tight fit when going from crank to crank that can be an issue. (Don't ask me how I know)

The ATI dampers do make some extra HP on an ARCA type 840 plus HP unit--at least on my friends dyno--he has seen up to 15HP on back to back test.
Fluid styles have been out of favor for a long time now in high end race units. They have several problems--they leak ( or Will leak) , the fluid turns to glue and they quit working and often cause other problems when that donut quits rotating in there, and..a rock or a slip with the wrench, you get a very small ding and there! It is now worthless way before it leaked or the fluid jelled. Look at how stock style dampers have NONE of those issues and I can't see any reason to ever use a Fluid style damper.
You just can't beat a high quality stock style damper unless you go to the ATI--The ATI's often require honing to fit as cranks these days are all over the place and...they make many hub styles that often will not work with Indy front covers, etc etc--Do your home work before buying one--they make a ton of different units for Mopar.
Pioneer stock replacement is a winner if you do not need SFI. The Aussie dampers from PRO come SFI or stock and are killer units for very reasonable

I say use a good oem unit uNless you have to mandated by a racing organization regulation.

I've been using Fluidampr dampers for 25 years with zero issues
I always slightly hone the bore on them there is no reason they need to be THAT tight.
Gus

Mine gave good service for 10 years but I am changing over to a ATI this year (only because I put a ding in it). The only thing I wasn't fond of was that the fluidamper is RIDICULOUSLY heavy on the nose of the crank...

My name is Ivan and I work for Fluidampr. I am here to answer any questions you may have regarding our product. I am NOT here to try and sell, just educate on the FACTS of Fluidampr as there is a lot of myths about our product.

The education... Fluidampr's viscous technology was invented by our sister company, Vibratech TVD, in 1946 for diesel engines. Viscous dampers continue to be used on over 90% of heavy duty engines and we are an OEM supplier to many of these manufacturers. This technology can also be found OEM on high end super cars such as the Ford GT40, Lamborghini Gallardo, Audi R8, and is even now being used OEM by Dodge Cummins on their 6.7 diesel engines. We were approached by Nascar engine builders in the 1980's to develop performance dampers for their high output gas engines.

I personally travel the country performing education seminars on torsional vibrations and damper solutions as well as work closely with top engine builders performing torsional vibration analysis.

I will not get into an argument over which is better Fluidampr or ATI. I am not here to do so. Again, I am here to provide the facts and to put to the ridiculous claims that certain people "heard" from a friend to rest. In all of my testing I have found that these are both premium dampers that are so far ahead of the competition it is not even close. During this testing we measure torsional vibrations by mounting an infra-red laser pick up and a special pulley to the crank. This is measured in peak to peak twist of the crankshaft. Every time the engine fires it twists the crankshaft ahead of its natural rotation and then the crank rebounds back to its position causing vibrations to travel back through the crankshaft reaching critical engine components and robbing the engine of power. During this testing on an engine dyno we measure H.P. and Torque. Again, no comparison both Fluidampr and ATI continuously put up the greatest power numbers over every other unit on the market. I can sit here and tell you how why I know Fluidampr is better, but I am biased right? So lets leave that for you. But I will challenge anyone who has access to a dyno to put the same size diameter (or close within a 1/4") ATI and Fluidampr on a crankshaft, run a back to back comparison on the same engine, same day and show me that Fluidampr does not put up the highest numbers.

Now to the facts… Fluidampr’s do not leak! Is it possible, sure anything is possible it is a manufactured part. And I might add a 100% made in the USA manufactured part with only North American materials. I can tell you this, I worked for Fluidampr’s parent company, Horschel Brothers Precision for 12 years as a machinist and supervisor and then for Fluidampr for the past 3 years and I have yet to see a performance Fluidampr that has left our shop and leaks. They are in a hermetically sealed housing and are 100% nitrogen leak tested before leaving the factory. I have had dampers come back that were thought to leak but in fact they do not and often it is a fluid from another engine component. My advice to anyone with a thought to be leaking Fluidampr is to remove the unit completely wash and dry it then set it upside down on some paper towels. The fluid inside is 45,000 thicker than 30 weight motor oil and very sticky to the touch. In a performance application the damper will last the life of the engine and does not go bad. The viscous silicone fluid will not harden or turn to glue in a performance application. I say this because on a heavy duty engine, due to the severe punishment of a constant running diesel engine, the damper should be replaced every 500,000 – 750,000 miles or equivalent in hours on gen sets. Small dings, sorry again, false. The damper housing is a minimum of an 1/8” thick. A rock that can reach the damper and a slip of a wrench is not going to hurt the housing. We warn people not to beat them onto a crankshaft with a hammer because this can cause damage and it is better to be safe.

Now that I have that out of the way, please feel free to ask me any questions or for a quicker response contact me direct via email at ivan.snyder@fluidampr.com

By the way… I would like to share this link. This gentleman contacted us a few weeks back regarding a 25 year old damper he had run in the mid 80’s when we first released dampers. Please check this out:
http://www.fluidampr.com/news/does-a-flu...ts-damper.-112/

Wasn't expecting Ivan to jump in on this conversation but he just backed up my machinist's words and even though my Damper hasn't been run and is almost 20 yrs old, I feel without a doubt that it will do its job as if I just bought it yesterday.

Thanks for chiming in Ivan

You are certainly welcome Pyper, thank you!

For cmansell, our original 440 damper we developed was for a Nascar and certain drag racing engines where they did not incorporate the OEM pulley and used their own modified pulleys. We have since corrected the issue and the OEM pulleys will mate up with part# 720311. I will try and attach a drawing.

If not this drawing and any other drawing for our dampers can be obtained by contacting me direct at ivan.snyder@fluidampr.com or by calling 716-592-1000 and asking for me or anyone in tech. support.

Hope this helps.

I can attest to the durability and performance of the "Original" Fluidamper.
Mine has been on my big blocks since the early '90's, Same one!..... 20 YEARS! Not one issue!
Stock block, stock crank and has seen 8,500 rpm a few times
I plan to retire it when I retire from racing along with my Molodon gear drive

Thank you roadhazzard. We are glad Fluidampr has proved the test of time for you as well.

Most builders and enthusiasts who use Fluidampr, love and use them for life. Again, there is just so much misinformation put out there. And the internet has just made it worse. Now everyone has an opinion and in most cases it is just that. I have heard every possible fallacy you can think of. The silicone hardens over time, the silicone settles, they do not balance, the crankshaft breaks, etc.It is generally an "I heard" situation vs. anyone providing true evidence that a failure or problem can be directly attributed to Fluidampr. Have crankshafts broken with Fluidampr installed? Sure. But I can assure you so have ATI and many other dampers for that matter. We are talking about monster power plants for engines. We (motorsports in general) are constantly looking for a little more, a little edge. Eventually something is going to break whether it be a crankshaft or any other engine component. I know one crankshaft manufacturer who puts a slip of paper in with every crankshaft they sell that states they will not warranty if a fluid type damper is used. It is so much easier to point to a damper than warranty a cheap offshore crankshaft. Not to mention this same manufacturer sells a cheap rubber damper with their name on it, so why would they endorse our damper? Again, the OEM's that use Fluidampr both in gas and diesel engines would not do so if they broke crankshafts or did not work as we claim. I am confident that more OEM's would use them if it wasn't for cost. It is much cheaper to manufacture a rubber damper than a viscous damper.

I appreciate the input of folks in the know.
That is what makes this forum great!
I have seen about 4 SBC Fluidampers that , for some reason the inner ring would not spin, turn, whatever. The engines performance would suffer and it took a while to locate the problem. Swap dampers and away they went. I have had 2 Mopar units with same issue. This is over a span of about 15 years.
I have to add, if you get an ATI and race with it in a No Pully situation you Better put bolts in the pully holes to keep that thing in one piece. I had a 500 CI BB Mopar that I was babysitting at the track one day--car ran 5.61, 5.60, 5.60 whatever and all of a sudden driver reported running over a rock or some object downtrack. Upon examination we discovered the ATI damper ring had left its hub and was gone. We dashed over to the flea market as this was a Mopar race/flea/show scrounged a stock damper, smacked it on and car went another few 5.60's so...You can have issues with any brand anytime.
Thanks for the professional input, I try to learn every day.

Is there any truth to a genuine fluid damper having balance issues in cold weather ?

And what is the recommended clearance to the crank hub ?

I have one I purchased when Vibratech owned them and I will be using it soon on a hemi build

Thank You