New Dorman balancers

[matuva]

The serpentine pulley is itself balanced. Put it on or not will do nothing in a balancing process

 

[3500GMC]

Ya the pulley should be neutral balance.

Engine machine shop balancers spin a 'bob weight' that simulates the weight of the pistons, rods, rings, bearings and even a calculation for oil weight while spinning *smoothly* on the fixture. Engines do not spin electric motor smooth while running-especially diesels.. I suppose that's why Fluidampr wants you to balance with a non-fluid damper to avoid the silicone fluid bunching up and doing weird things with the balance.

The accessory drive pully is rubber bushed, I guess, to lessen the shock on the belt and what it drives.

 

[JMJNet]

It sounds like another ACDelco part is required for Harmonic Balancer.

 

[Matt Bachand]

The serpentine pulley is itself balanced. Put it on or not will do nothing in a balancing process

But isn't the HB itself balanced too? It can't be made universally specifically balanced for every engine. They say the HB weight and balance helps to balance the front of the engine, as the flywheel and transmission weight stabalize the back of the engine.

Or maybe it is, because it has a 'keyway' it can only go one way, unless that is to help eliminate slip, or possible both.

 

[ak diesel driver]

internally balanced engines have a zero balanced flywheel and HB externally balanced engines have a weighted side to them. And yes they are universal for all like engines ie all 6.5 diesels etc. That puts them within spec. When you have an engine balanced they are using a tighter spec than factory.

 

[Matt Bachand]

internally balanced engines have a zero balanced flywheel and HB externally balanced engines have a weighted side to them. And yes they are universal for all like engines ie all 6.5 diesels etc. That puts them within spec. When you have an engine balanced they are using a tighter spec than factory.

6.5 is externally balanced. Thanks AK, good info. So a FLUIDAMPR must have the same counterweight as DELCO HB, but uses fluid instead of rubber??

Now if this is true, (what i said) I'm not sure again why you can't balance an engine with fluidampr, I understand the fixed RPM isn't a true replication of engine spikes and torque, but isn't a balancing balancer balanced? Lol.

 

[ak diesel driver]

the HB just soaks up the shocks from the engine it doesn't balanc the reciprocating assy. same for the crank pulley it just soaks up the shocks from the accys

 

[Matt Bachand]

Then why is it necessary to have on the engine while its getting balanced?

 

[Matt Bachand]

So the HB must not be balanced, it must have counterweights to bring the rotating mass closer to balanced specs.

The crank pulley is balanced, thus doesn't effect engine balance.

 

[ak diesel driver]

Then why is it necessary to have on the engine while its getting balanced?

externally balanced engine so the counterweight needs to be in place

 

[ak diesel driver]

So the HB must not be balanced, it must have counterweights to bring the rotating mass closer to balanced specs.

The crank pulley is balanced, thus doesn't effect engine balance.

HBis not zero balanced so yes it has counterweights and the crank pulley is zero balanced

 

[3500GMC]

As said above, the HB is counter-weighted also the flywheel or flex plate is too. There is a keyway in the HB, and a dowel in the crank flange for the flex/flywheel. All other external spinning parts are neutral balance.

Fluidampr has a liquid that will affect balance when on a balance fixture vs. an OEM that has no liquid. I guess I really do not know the physical/ mechanical properties of a liquid within a chamber when spinning. Fluidamper states to use a good OEM HB if you are balancing the recip. assy. Then switch back to the Fluidampr. The 'weight' of both HB's counter weights are the same, but the overall weight of the Fluidampr is way heavier. Much of this weight is the huge amount of silicone in that chamber. Added dampening over OEM.

Now I want to call Fluidampr for the real explanation. ):h

 

[Detroit Dan]

OK, I am probably many years overdue to change this. What should I buy? I am poor and cheap, but I like my motor and don't want to blow it up with Chinese junk. But if I have to spend $500 it is not going to get done and I will continue to run on borrowed time.
How much is an ACDelco? Or any other comparable quality piece.

 

[Matt Bachand]

Delco on rockauto was around 80 bux IIRC, vs 60 or so for dorman. And to be fair Fluidampr is around 450 or so, so its a 370 dollar difference..

I guess it all depends on how long you plan on keeping the 6.5, and if yours dies, are you going to get another 6.5.

 

[Big T]

I put the Dorman HB and Pulley on the '95 and no problems. AC Delco is probably made in either Mexico or China. Most all low technical value products are made in China anymore. Socialist unions have priced themselves out of jobs and work, so it only makes sense that a socialist country steals their work.

 

[Matt Bachand]

I put the Dorman HB and Pulley on the '95 and no problems. AC Delco is probably made in either Mexico or China. Most all low technical value products are made in China anymore. Socialist unions have priced themselves out of jobs and work, so it only makes sense that a socialist country steals their work.

I agree with that.

 

[BigBlue]

just for documentation, I tried to get a few close ups of the dorman
china balancer. this is after 7000 miles of driving.

and no, it didn't look like this when I installed it!

 

[Big T]

Looks like cracked paint. They paint them and I'd expect the paint to crack given that the rubber is absorbing engine shocks.

 

[Big T]

Looks like cracked paint, not cracked rubber.

 

[ak diesel driver]

except for the missing pieces