C2 Blower Motor

[Michael A.]

[Michael A.]

[Mark F.]

Re: C2 Blower Motor

Mike,

Did you happen to test the motor operation while it was out of the car? If you did, I'll bet there was no noise as heard in your video, right?.

The '67 UPC 1 ASM Sheet D6 doesn't show how the motor mounts, but they do have one "insulator" in there #2 part number 3830770 farther back toward the firewall. Does your AIM show installation requiring pliable isolation mounts, or an isolating gasket at the motor-to-blower housing interface?

To me, the sound on the video is like a fiberglass component vibrating (low frequency rattling?) in resonance with the motor speed (high speed being the worst).

You've probably already ruled out direct squirrel cage contact with anything, so this is a long shot, but do you know if there are any components from the blower motor and beyond downstream to all discharge points that have not been fully tightened yet (or isolated) during your restoration so far? thx, Mark

[Tom E.]

Re: C2 Blower Motor

MIke,
To add to Marks line of thinking you can take a 12-18v drill battery and hook it up to the motor and cage assembly while it is out of the car and see if it makes any noise. This would confirm or eliminate other sources of the noise besides the cage and motor assembly. I did this with mine before I assembled everything in the car to eliminate having to remove and repair.
To

[Dan B.]

Re: C2 Blower Motor

Mike, I am wondering if the noise you are hearing is not related to the uneven squirrel cage spinning and creating an uneven air flow noise and imbalance on the shaft as it spins. You should be able to straighten up that cage by tweaking the low point until you can get it to run straight. I see you have some balancing weights on the blades which is good, so I think it will improve once the cage is straightened. By the way, that little up and down movement on the shaft is normal.

[Mark F.]

Re: C2 Blower Motor

Mike,

did you ever figure out what the blower motor noise was?

[Michael A.]

[Richard G.]

Re: C2 Blower Motor

I think its unbalance. One can't have that much run-out in the axial direction without some unbalance know as couple unbalance in the industry. When you get it running try hand holding the motor, with it running, without and again with and the squirrel cage fan installed. I would replace the fan as it is the likely issue. I have had luck balancing fans using the trail and error method using clay and then replacing it with a permanent weight. Primitive compared to the sophisticated vibration software I used at work but it can be very effective.
You mentioned "you attempted to straighten the shaft". I am not sure what that meant but typically its the fan wheel that bends not the shaft.
Rick

[Mark F.]

Re: C2 Blower Motor

My assumption is that it is meant to address drafts and not to help with vibration. Is that your understanding? Are you saying that it should mount between the heater box and the firewall and that it provides some anti-vibration function? Thanks,

Michael,

Based on my recollection of noise and vibration courses I have had, soft, pliable materials will help damp vibration (disrupt or dissipate potential flow-thru mechanical energy) - if they are not crushed essentially to the point that their pliability is gone. I agree with you it seems the real function was for draft (air leakage?) control - any reduced vibration associated with that part would only be a "hitch-hiker" benefit . A true isolation mount (vibration damping? - I may be confusing correct terms?) would kinda be like an engine mount where two separate pliable materials (rubber) are kept in contact with each other - one end bolted to the engine - the other to the frame to disrupt and prevent coupling of the engine vibration frequencies at various RPMs from shaking the heck out of the frame...I hope your OEM fan does the trick for you - finding and correcting noises in your car can be maddening...thx, Mark