Fluiddamper question
Had a 1976 L-82, 4-sp
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From: Some days your the dog and some days your the hydrant.
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I've had one on mine for 17 years and ~20K miles. I'm not easy on my engine and I've had no problems with mine. I also noticed that that when fully seated up on the crank sprocket it still looks like it only went on half way.
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I've had different 6.250 inch FD's on some serious motors and they work fine and never failed. small diameter and less weight is a trade off against 7 and 8 inch that actually provide more dampening.
Presently my 383 has a FD and my 434 has a ATI. Both 6 inchers. What sucks about the newer ATi is that you can't hardly read the degrees after 4 years. They are painted on and a power steering fluid leak ruined the lettering.
On the other hand everything has happened to the old FD after being on 5-6 different motors and the laser eched degrees are all nice and clear
Presently my 383 has a FD and my 434 has a ATI. Both 6 inchers. What sucks about the newer ATi is that you can't hardly read the degrees after 4 years. They are painted on and a power steering fluid leak ruined the lettering.
On the other hand everything has happened to the old FD after being on 5-6 different motors and the laser eched degrees are all nice and clear
Last edited by gkull; Jun 14, 2012 at 05:50 AM.
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I've had one on my 61 with a 383 for several years with no issues.
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St. Jude Donor '05
Been running the small FD for many many yrs no issues.
Beginning to think though a dampner with the outer ring that oscillates some can dampen the twisting forces of the crank a little better. Maybe Im ignorant...
Beginning to think though a dampner with the outer ring that oscillates some can dampen the twisting forces of the crank a little better. Maybe Im ignorant...
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St. Jude Donor '05
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Melting Slicks
Joined: Mar 2002
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From: Beringen
I just got someone tell me that these dampers never repeat on a balancing machine. This makes you think how in the hell they balance them from the factory.
I would think they will always have an out of balance issue.
Decided to move towards the ATI.
I would think they will always have an out of balance issue.
Decided to move towards the ATI.
Drifting
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From: League City TX
Here is what Fluidampr says about the topic-
Why can't Fluidampr or Streetdampr be spun on a balance machine?
Balancing a crankshaft with the Fluidampr or Streetdampr is not recommended. The Fluidampr (or its damper ring) and the Streetdampr contain an inertia ring that can rotate inside. This inertia ring is balanced to very close tolerance specifications at the factory but may not be to perfect "zero" balance. When the damper is spun on a balance machine, this inertia ring may rotate inside the damper and the operator may be chasing this small imbalance while attempting to balance the crankshaft.
When the damper is installed and running on a combustion engine, the shear forces on the silicone fluid inside the damper from the torsional moments of the engine crankshaft, centers the inertia ring on its bearings. A balance machine does not generate torsional shear forces and the inertia ring may not be completely centered in its bearing clearance gaps.( IT WILL BE CENTERED AND IN BALANCE WHILE RUNNING ON AN ENGINE )
Why can't Fluidampr or Streetdampr be spun on a balance machine?
Balancing a crankshaft with the Fluidampr or Streetdampr is not recommended. The Fluidampr (or its damper ring) and the Streetdampr contain an inertia ring that can rotate inside. This inertia ring is balanced to very close tolerance specifications at the factory but may not be to perfect "zero" balance. When the damper is spun on a balance machine, this inertia ring may rotate inside the damper and the operator may be chasing this small imbalance while attempting to balance the crankshaft.
When the damper is installed and running on a combustion engine, the shear forces on the silicone fluid inside the damper from the torsional moments of the engine crankshaft, centers the inertia ring on its bearings. A balance machine does not generate torsional shear forces and the inertia ring may not be completely centered in its bearing clearance gaps.( IT WILL BE CENTERED AND IN BALANCE WHILE RUNNING ON AN ENGINE )
Safety Car
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From: anchorage ak
Thats interesting. But they still spin them up to 12,000 rpm for sfi rating, you'd figure that if it was out of balance at that kind of rpm, it would come apart.
Last edited by bluedawg; Jun 18, 2012 at 02:07 PM.
Thread Starter
Melting Slicks
Joined: Mar 2002
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From: Beringen
Here is what Fluidampr says about the topic-
Why can't Fluidampr or Streetdampr be spun on a balance machine?
Balancing a crankshaft with the Fluidampr or Streetdampr is not recommended. The Fluidampr (or its damper ring) and the Streetdampr contain an inertia ring that can rotate inside. This inertia ring is balanced to very close tolerance specifications at the factory but may not be to perfect "zero" balance. When the damper is spun on a balance machine, this inertia ring may rotate inside the damper and the operator may be chasing this small imbalance while attempting to balance the crankshaft.
When the damper is installed and running on a combustion engine, the shear forces on the silicone fluid inside the damper from the torsional moments of the engine crankshaft, centers the inertia ring on its bearings. A balance machine does not generate torsional shear forces and the inertia ring may not be completely centered in its bearing clearance gaps.( IT WILL BE CENTERED AND IN BALANCE WHILE RUNNING ON AN ENGINE )
Why can't Fluidampr or Streetdampr be spun on a balance machine?
Balancing a crankshaft with the Fluidampr or Streetdampr is not recommended. The Fluidampr (or its damper ring) and the Streetdampr contain an inertia ring that can rotate inside. This inertia ring is balanced to very close tolerance specifications at the factory but may not be to perfect "zero" balance. When the damper is spun on a balance machine, this inertia ring may rotate inside the damper and the operator may be chasing this small imbalance while attempting to balance the crankshaft.
When the damper is installed and running on a combustion engine, the shear forces on the silicone fluid inside the damper from the torsional moments of the engine crankshaft, centers the inertia ring on its bearings. A balance machine does not generate torsional shear forces and the inertia ring may not be completely centered in its bearing clearance gaps.( IT WILL BE CENTERED AND IN BALANCE WHILE RUNNING ON AN ENGINE )
As for spinning up to 12000 rpm : flying apart is mainly because of centrifugal force. Has little to do with imbalance. Imbalance creates stresses mainly in the crank.