Yellow Bullet Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
233 Posts
Discussion Starter #1
I just picked up a new motor after gernading my old one. It is a 0.040 over 400 (408) and it is externally balanced. Is there any reason I should be concerned about this? Is internally balancing better? It has a Fluid dampener on it and a sfi flex plate. I am just wondering if I should run it the way it is or send it out to have it internally balanced???
 

·
Senior Frog
Joined
·
10,315 Posts
my last BBC was Ext balanced......it had a decade of runs on it and
a few thousand of passes,still tunning today.......never an issue

Your only problem is you have a 400 GM Block,they crack under pressure !
 

·
Registered
Joined
·
439 Posts
Spend the little bit of extra money and internal balance it, at least on the front. Seen too many 400 cranks with the key way beat out.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #4
The block has splayed caps on it and a forged crank with eagle h beams. It has je/srp pistons and it will see some nitrous. I am a big fan of internally balancing, but I am curious if the external balancing is going to be an issue? I am also on a budget, so if I can save some money by not sending it out, I will run it the way it is.
 

·
Registered
Joined
·
1,627 Posts
Im in the same boat as you with a SBF, put in some heavy nitrous pistons and H beams and its tough to stay internally balanced without spending a bunch of money. I havent heard anything negative beside the usual crank snout and having to disassemble the engine to rebalance it if you replace the balancer or flexplate later on. I've learned of a few people running 8000+ with externally balanced engines
 

·
Registered
Joined
·
27,956 Posts
I would be more concerned with the fluid in the Fluidampr gelling up than internally balancing the motor. I ran a 400 for 11 years on the street and several more on the track externally balanced and hitting it with 250+ all the time and never had a problem. That motor also had heavy ass TRW slugs in it.
 

·
Registered
Joined
·
233 Posts
Discussion Starter #7
I would be more concerned with the fluid in the Fluidampr gelling up than internally balancing the motor. I ran a 400 for 11 years on the street and several more on the track externally balanced and hitting it with 250+ all the time and never had a problem. That motor also had heavy ass TRW slugs in it.
Fluidamper gelling up? Is that a common problem? Do you have any suggestions on what kind of balancer I should run? So besides that you think it should be fine the way it is?
 

·
Registered
Joined
·
16,659 Posts
Fluidamper gelling up? Is that a common problem? Do you have any suggestions on what kind of balancer I should run? So besides that you think it should be fine the way it is?
I have heard people say a Fluidamper would gel up over time but have no clue as to how true that is as I have never witnessed it. I prefer the ATI dampers, have ran them on numerous applications with no issues.
 

·
Registered
Joined
·
27,956 Posts
I have seen 2 of them gel up. I just run a standard sfi approved damper. But the ATI's are very nice also. Seen quite a few people running Rattlers also, just be warned when you shut the motor off it will sound like it has a bearing problem. But it's just the damper. As long as the rotating assy. is balanced I would run it just like it is, just use a different damper to be sure.
 

·
Registered
Joined
·
8 Posts
Hi guys,

I happen to work for Fluidampr. It is a common misunderstanding that Fluidampr will "gel-up" overtime. The fact of the matter is that the silicone based dampening media we put in our dampers is gel at the time we put it into the damper. It is a silicone fluid that is 45,000 times thicker than 30 weight motor oil. This is an excellant dampening media because of its tensile strength, density, and low friction properties. It is also the best dampening media available, other dampers absorb vibrations through rubber or mechanical methods that have to be tuned to each frequancy of harmful torsional vibrations. Only Fluidampr with its silicone technology can effectively control torsional vibrations at all frequancies. Visit or wesite www.Fluidampr.com for more information. Hopes this helps with the understanding of how fluidamprs work!
 

·
Registered
Joined
·
27,956 Posts
So what causes them to roll across the floor and have a different weighted spot in them that doesn't settle out? In other words you take a new one and roll it across the floor and it just rolls. You take one that has "gelled up" for lack of a better term and it rolls across the floor slows, then rolls fast, slows, then rolls fast, and eventually stops, rocks back and forth a couple times and then stops.


Is that supposed to happen?

Maybe gel up isn't the right term. Possibly, bunch up in one spot versus being equally displaced around the entire damper? Or possibly, there was an air pocket in it?
 

·
Registered
Joined
·
8 Posts
This happens because there is a differance between your arm and a crankshaft. You cannot get enough centrifugal force to have the damper perform properly.

During manufacturing prior to boxing and shipping the last stage is to finish fill the damper with fluid ("gel"). The damper is filled with an even placement of silicone. So it will appear to spin true once removed from packaging. Once spun on a crankshaft and then brought to a stop, you are correct, the fluid may settle heaver in one place. Therefore, theoretically, it only takes one start of an engine and "that" will happen. Once the engine is started again, it creates enough force for the silicone and inertia flywheel to do its "work" and rebalance itself. This is why you do not have to balance a fluidampr on your crankshaft when balancing the engine.

Unlike other dampers Fluidampr does not need to be rebuilt or repaired after so long. Fluidampr never has to be replaced unless it is physically damaged.

Did I mention they are completly engineered and manufactured in the USA!!
 

·
Registered
Joined
·
27,956 Posts
This happens because there is a differance between your arm and a crankshaft. You cannot get enough centrifugal force to have the damper perform properly.

During manufacturing prior to boxing and shipping the last stage is to finish fill the damper with fluid ("gel"). The damper is filled with an even placement of silicone. So it will appear to spin true once removed from packaging. Once spun on a crankshaft and then brought to a stop, you are correct, the fluid may settle heaver in one place. Therefore, theoretically, it only takes one start of an engine and "that" will happen. Once the engine is started again, it creates enough force for the silicone and inertia flywheel to do its "work" and rebalance itself. This is why you do not have to balance a fluidampr on your crankshaft when balancing the engine.

Unlike other dampers Fluidampr does not need to be rebuilt or repaired after so long. Fluidampr never has to be replaced unless it is physically damaged.

Did I mention they are completly engineered and manufactured in the USA!!
Only did the roll test on one of them, the other was just replaced with a standard steel SFI balancer and the vibration went away. That was the concern...the vibration didn't settle out. That is why it was thought that the fluid inside collected in one spot and didn't distribute itself back out.

Could it be from sitting without being started over the winter? Just trying to see what exactly happened to the two I'm talking about. If it matters one was in a dirt car, the other in a drag car.
 

·
Registered
Joined
·
8 Posts
Now i am confused... I am not sure what happened in your situation.

Silicone fluid is a very good damping medium because is reletively unaffected by tempature changes. It provides consistent damping in both winter and summer. The fluid will not deteriorate if the Fluidampr is not used for a period of time. Also, you do not have to wait for the vehicle to warm up as delivers consistant performance over the entire range of operating tempatures.

I understand your concern if you changed the damper and the vibration went away the first thought would be bad damper.

I am anxious to see if others comment as i am not sure what else could be wrong.
 

·
Registered
Joined
·
14,487 Posts
I would think that a fluid damper would work best when full, that way the damper body is in contact with all of the media. Could these problems acould be caused by loss of contact between the gel and the body? but I could be wrong.... Do you only fill them partially by design?
 

·
Registered
Joined
·
7,489 Posts
This happens because there is a differance between your arm and a crankshaft. You cannot get enough centrifugal force to have the damper perform properly.

During manufacturing prior to boxing and shipping the last stage is to finish fill the damper with fluid ("gel"). The damper is filled with an even placement of silicone. So it will appear to spin true once removed from packaging. Once spun on a crankshaft and then brought to a stop, you are correct, the fluid may settle heaver in one place. Therefore, theoretically, it only takes one start of an engine and "that" will happen. Once the engine is started again, it creates enough force for the silicone and inertia flywheel to do its "work" and rebalance itself. This is why you do not have to balance a fluidampr on your crankshaft when balancing the engine.

Unlike other dampers Fluidampr does not need to be rebuilt or repaired after so long. Fluidampr never has to be replaced unless it is physically damaged.

Did I mention they are completly engineered and manufactured in the USA!!
so the 20yr old damper i have is still okay to use ? it hasn,t been run nice 1994
 

·
Registered
Joined
·
8 Posts
First mikeyfrombc,

That is correct, the damper should be fine to use, providing it has not been physically damaged in any way ex. dropped, beat with hammer, in an accident, etc. Fluidampr performance dampers are engineered to not wear out or have to be rebuilt. Now we do recommend that if you are putting a lot of money into, or building a high performance race engine and your damper is over 10 yrs old that you replace it with a new Fluidampr.

Second bottlefed1,

Without giving away too much of our proprietary information on this forum i can give you a little about our design. There is an inertia ring/flywheel inside of our damper housing. There is a cavity within the housing that this inertia ring sits. There is a small area between the housing and flywheel called a shear gap. In manufacturing this shear gap is filled with the viscous silicone flluid. We fill all gap area with silicone fluid. Again, keep in mind this fluid is very thick (again 45,000 times thicker than 30 weight motor oil) and would not be able to totally disipate from one area. You can see a picture on page 5 of our catalog at www.fluidampr.com that shows what i am explaining.
 
1 - 17 of 17 Posts
Top