12 to 18VDC on 69 Camaro?

Discussion in 'The Projects Forum' started by jweb47, Jul 22, 2008.

  1. jweb47

    Thread Starter New Member

    Jul 22, 2008
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    Sorry to bother anyone but, I own a 60s muscle car that inherently has low air flow volume when the blower is on high. The AC system has been completely rebuilt and calibrated with everything working properly except it needs more flow on high blower. I was thinking of trying to run the new 12 vdc blower motor on 16 or 18vdc to increase it's RPM. It draws a lot of amps on high so I thought I should ask if this is possible/cost effective. Thanks for any help.
     
  2. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    It could be done but due to the high current involved I think it could be expensive, you would need a high current DC-DC converter. I also think that the motor would soon die if it were run at 18V as the power would more than double.

    Could you add another blower to run in parallel with the existing?
     
  3. jweb47

    Thread Starter New Member

    Jul 22, 2008
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    I wish I could. I thought about a duct booster but the only outlets that have round ducts are 2 running to each side of the dash. The center vent is molded plastic that is shaped to the contour of the compact dash area prohibiting any kind of booster. The only option I see is to make the motor run faster or somehow, find a motor that will fit that has higher RPMs...luckily, these motors are only 20.00 and made by Siemens.
    I'm thinking about picking up another motor and see how it runs on 24 volts on the bench. If that looks promising by running two 12v batteries in series, then perhaps step that down?
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    What kind of shape is the squirrel cage in?

    If there's any buildup of gunk, rust, imbalance, etc. - it'll kill it's efficiency.

    Check it's balance. It'll be a bear to balance it, but worth it if it's in basically sound condition. The old squirrel cage blower fans were stamped out of steel and welded together. Nowadays, they're all plastic.

    At high RPM, if your squirrel cage is out of balance, it will place a very high load on the bearings of the motor, limiting it's maximum speed.

    If the squirrel cage has crud or rust on the blades, or if they're bent out of shape, the airflow will be severely reduced. It'll seem to work OK at slow speeds, but won't have any "oomph" on high.

    Check your ductwork for obstructions, particularly the air inlet and the plenum below the inlet. You might find a bunch of leaves and crud in there. Make sure the drain is working properly.

    It's tough getting a 40 year old classic back up to it's original snuff. But it's worth the effort.

    I'm afraid that trying to boost the voltage to the motor could be very counterproductive. Excercise all traditional options first.
     
    Last edited: Jul 22, 2008
  5. Audioguru

    New Member

    Dec 20, 2007
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    I agree.
    Operating the motor with a voltage higher that it was designed for will make it smoke and burn out. Especially sine its current is probably too high anyway because of all the things mentioned that slow it down and increase its current.
     
  6. jweb47

    Thread Starter New Member

    Jul 22, 2008
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    The complete system including everything mentioned here has been disassembled, reconditioned or replaced and reassembled with all doors and ducts sealed and adjusted. I bench tested the motor/fan before assembly and it looked perfect. I'm not a novice at this...this is my third first generation Camaro I've rebuilt which all had the same problem. I'm just at the point that if there is a way to fix it at "almost" any cost, I'm doing it. I'm here because I feel it's going to take an electrical solution because everyone on the Camaro forums are more concerned with performance than creature comforts, thus no one has tried to tackle this problem that I can find. Even though all the suggestions so far have already beed covered, I'm hoping someone here may come up with a solution that hasn't beed considered. Thanks again for everyone's effort.
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Have you tried running the fan on the bench at the higher voltage to see if you get the effect you want? That would also be a good opportunity to measure the current draw, which you will need to know for any electronic solution. John
     
  8. jweb47

    Thread Starter New Member

    Jul 22, 2008
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    That's pretty much what I said I will probably do on my previous post. This model car is a bear to get the motor out...that's why I'll buy a new one for this test
     
  9. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    I tend to think that an effective solution would have to be mechanical. From an electrical perspective all you can do to increase air flow is spin the motor faster which means more noise in the car and more (probably unacceptable) stress on the motor. I suspect that without resorting to some kind of mechanical re-work of the blower, the gains will be quite small.
     
    Last edited: Jul 23, 2008
  10. jweb47

    Thread Starter New Member

    Jul 22, 2008
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    How about removing some windings on the armature to increase RPM at 12v? Here's a pic of what this motor looks like. If I knew where to start, I'd try to find a similar motor with higher RPMs and adapt it to fit. Thanks to everyone willing to talk to me about this.
    [​IMG]
     
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