OT,Will an automotive alternator work if it is turning reverse to the normal rotation
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    Default OT,Will an automotive alternator work if it is turning reverse to the normal rotation

    Seems like it should not matter, but till now I have never had to do it. Will it make full power, any power at all?

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    no difference

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    It will generate electricity just as well, only concern I see is that alternators have a built in cooling fan. It will move less air if spun the reverse direction so it will not cool as well. Long runs at high power may cause early failure.

    CarlBoyd

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    Quote Originally Posted by CarlBoyd View Post
    It will generate electricity just as well, only concern I see is that alternators have a built in cooling fan. It will move less air if spun the reverse direction so it will not cool as well. Long runs at high power may cause early failure.

    CarlBoyd
    Yeah, I was planning on making a new fan for the reverse rotation if as I suspect It will generate in reverse rotation.

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    Quote Originally Posted by moonlight machine View Post
    Yeah, I was planning on making a new fan for the reverse rotation if as I suspect It will generate in reverse rotation.
    Most I have seen use a radial blower that looks like rotation
    wouldn't matter.

    Testing an alternator on a spin stand with a manometer should
    prove fruitfull.

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    cooling fans? That won't matter much. centrifugal fans work both ways as well.

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    Don't know what brand you're dealing with. Back in the day, GM engines were set up to run backwards for marine applications. Hence, starters & alternator fans rotated backwards as well.

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    As others have said, it will work. The only caveat is that it is best to replace the brushes if using a used alternator.

    The brushes take a set as they wear in and don't make proper contact when reversed. The problem is that they still make contact but only in a small area leading to possible arcing.

    They also do make cooling fans for either rotation. The fans do work better in the direction they are made for but less efficient when reversed.

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    Alternator so no difference but some have clutches in them so they can freewheel if engine speed changes quickly.

    Ford police cruisers that CHP uses have these as the standard ones would break the shafts.



    Sent from my SAMSUNG-SGH-I337Z using Tapatalk

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    Quote Originally Posted by Tony Quiring View Post
    Alternator so no difference but some have clutches in them so they can freewheel if engine speed changes quickly.

    Ford police cruisers that CHP uses have these as the standard ones would break the shafts.



    Sent from my SAMSUNG-SGH-I337Z using Tapatalk
    Can you link to these special CHP alternators? I've never seen such.

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    Quote Originally Posted by CalG View Post
    Can you link to these special CHP alternators? I've never seen such.
    Might want to go see what P/N alternator MOPAR has put onto their latest Dodge Demon funny-car.

    Packaged insanity on four wheels. Well. Just two, sometimes.

    One suspects the name is no accident, and they actually ARE doing joint-venture Engineering with the Devil.

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    Cal G

    Over here in the UK- all the alternator clutches I have seen are built in to the drive pulley - I know VW fit them a lot.

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    Shouldn't make a difference. The ATI Procharger kit I put on my old old 1987 corvette took the stock alternator, flipped it around to face the engine and you would install the included reverse vane fan.

    Also you had to of course safety wire the nut as it would run the chance of unscrewing since it was running in reverse. No wiring changes or anything else of the sort. This was with the stock 1987 vette alternator. Worked perfectly for thousands of miles.

    EDIT: Dug through some pictures and found one of it. It was 12 years ago and number of project cars since then but it did work really well.

    p1020118.jpg

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    It will work but since it is backwards, it will take power out of the atmosphere, pull it through your headlights and such, then send it to your battery for storage. Then, when you really need it, it will go from your battery into your alternator stator where it will spin the rotor to send power through the belt into your engine's crankshaft. At that point, it can either be used to help propel the vehicle more faster, or it will be converted via the fuel system into raw gasoline which is then put back into the fuel tank for later use. It's all just energy conversion, you see.

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    GregSY, .............Has that new batch of foil hats come in yet?

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    Quote Originally Posted by Limy Sami View Post
    GregSY, .............Has that new batch of foil hats come in yet?
    Yes, they have. But they have already been sent back for exchange.
    We paper-pushers understand our receiving QA responsibility.

    The Idjut supplier shipped 'em for the wrong direction of rotation!

    Can't get decent suppliers for ANYTHING these days.


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    Quote Originally Posted by GregSY View Post
    It will work but since it is backwards, it will take power out of the atmosphere, pull it through your headlights and such, then send it to your battery for storage. Then, when you really need it, it will go from your battery into your alternator stator where it will spin the rotor to send power through the belt into your engine's crankshaft. At that point, it can either be used to help propel the vehicle more faster, or it will be converted via the fuel system into raw gasoline which is then put back into the fuel tank for later use. It's all just energy conversion, you see.
    I figured it would just suck power out of the battery!

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    Quote Originally Posted by Ziggy2 View Post
    As others have said, it will work. The only caveat is that it is best to replace the brushes if using a used alternator.

    The brushes take a set as they wear in and don't make proper contact when reversed. The problem is that they still make contact but only in a small area leading to possible arcing.

    They also do make cooling fans for either rotation. The fans do work better in the direction they are made for but less efficient when reversed.
    This is for a rich guy's old Indy Car, nothing used, all the best and new as well.

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    Quote Originally Posted by Tony Quiring View Post
    Alternator so no difference but some have clutches in them so they can freewheel if engine speed changes quickly.

    Ford police cruisers that CHP uses have these as the standard ones would break the shafts.



    Sent from my SAMSUNG-SGH-I337Z using Tapatalk
    The old Indy Cars that ran Buick and Chevy V6 stock block engines used a Delco alternator that was driven by a speedometer cable on steroids. It had an over run clutch in it as well as the engine speed would change faster than the alternator could and the cable would tie itself in knots.

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    Quote Originally Posted by moonlight machine View Post
    The old Indy Cars that ran Buick and Chevy V6 stock block engines used a Delco alternator that was driven by a speedometer cable on steroids. It had an over run clutch in it as well as the engine speed would change faster than the alternator could and the cable would tie itself in knots.
    "Old"? IIRC the Miller, Offenhauser/Meyer-Drake era, magneto ignition, no lights, external starter with 'bout a yard of shaft on it for the routine work, swap a small battery (if even..) rather than charge it during the race at all.

    LeMans? Not such a good approach.


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