C2:67 37 Amp Alternator - NCRS Discussion Boards

C2:67 37 Amp Alternator

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Gerard F.
    Extremely Frequent Poster
    • June 30, 2004
    • 3803

    C2:67 37 Amp Alternator

    I have my original 67 37A alternator in a box on the shelf. I took it off some years ago when I sensed that it wasn't putting out by the run down batteries. I have since put on add-on AC which requires a 60 amp or more, and with it a generic 60 amp alternator which took a took a full deduct at recent judging.

    The original alternator needs an overhaul anyhow, and I wonder if there is any way on an overhaul, the amps can be raised within the same case and undiscernable to judging.

    Can it be done? Or shall I just keep the 37A alternator for judging and the 60 amp for driving.

    Jerry Fuccillo
    #42179
    Jerry Fuccillo
    1967 327/300 Convertible since 1968
  • Joe L.
    Beyond Control Poster
    • February 1, 1988
    • 43193

    #2
    Re: C2:67 37 Amp Alternator

    Jerry------

    To make this conversion is VERY simple. In fact, you probably already have everything you need. If the "generic" 60 amp alternator that you're using is a Delco DN series alternator (such was the type used on all 1963-68 Corvettes as well as most other GM cars during the 63-70 period), you have what you need. Simply remove the STATOR from this alternator and use it to replace the stator in your original alternator. It will be a direct fit. Presto! Your original alternator is now a 61 amp alternator.
    In Appreciation of John Hinckley

    Comment

    • Gerard F.
      Extremely Frequent Poster
      • June 30, 2004
      • 3803

      #3
      Thanks, Joe

      I think you just got me 40 points on the next round, with a little work.

      Jerry
      Jerry Fuccillo
      1967 327/300 Convertible since 1968

      Comment

      • Gary B.
        Extremely Frequent Poster
        • February 1, 1997
        • 6979

        #4
        Joe: Amp boost; any downside?

        Joe,

        I think when John Pirkle rebuilds starters, he can and does turn them into hi-torque units, which gives one an ungraded unit for the same price with no obvious downside.

        For those of us with 37 amp alternators and no A/C, is there any downside to increasing alternator capacity if and when the time comes to me to get my 37 amp unit rebuilt?

        Gary

        Comment

        • Jack H.
          Extremely Frequent Poster
          • April 1, 1990
          • 9906

          #5
          Re: Joe: Amp boost; any downside?

          There's no downside to increasing the alt's internal output capacity...it's simply a matter of matching rotor and field windings to deliver the target output current. With a higher output alternator, all that happens is the voltage regulator turns the alternator OFF sooner since there's increased charging current.

          BUT, this won't change the PN, current rating, and date code stamped on the outside of the alternator's case... The original thread poster thought he'd get back judging points lost by such a configuration change!

          Comment

          • Gary B.
            Extremely Frequent Poster
            • February 1, 1997
            • 6979

            #6
            More is better

            Jack,

            In my case I've got a correct date code alternator, so it's not a question about getting back lost judging points. I just was wondering if more is better had any downside from the electrical perspective and it sounds like it doesn't. On the flipside, is there any significant advantage if one doesn't really need more than 37 amps?

            Gary

            Comment

            • Joe L.
              Beyond Control Poster
              • February 1, 1988
              • 43193

              #7
              Re: More is better

              Gary------

              The only downside that I can think of is that a higher amperage alternator may have more drag (and, consequently, hp consumption). However, overall, the amount of drag is going to be about the same since the actual overall output should be the same (unless one adds significant electrical load). So, there's really no significant downside from any functional perspective.

              On the other side of the coin, there's really no advantage to a higher rated unit if the lower rated unit serves all of the cars electrical requirements. A 37 amp unit should do so for most cars of the era. Not cars of today, however.
              In Appreciation of John Hinckley

              Comment

              • Gary B.
                Extremely Frequent Poster
                • February 1, 1997
                • 6979

                #8
                Thanks Joe, very clearly explained *NM*

                Comment

                • Gerard F.
                  Extremely Frequent Poster
                  • June 30, 2004
                  • 3803

                  #9
                  Re: Thanks Joe, very clearly explained

                  Gary,

                  I use my 67 more as a driver then for showing. I put on a Vintage Air System, which on high blower takes over 20 amps more towards 30. I put on a 60 amp generic when I put on the A/C system. On this I got a total deduct(40 points) last Saturday at Elk Grove, but I didn't lose as much on the Add-On AC.

                  The extra drag for the alternator is nothing compared to the extra drag for the compressor, and if you use something at full capacity for a long time, it's going to wear out quickly. But now I can be cool going to meets (especially in California). And now I have the path to the best of both worlds.

                  Jerry Fuccillo
                  #42179
                  Jerry Fuccillo
                  1967 327/300 Convertible since 1968

                  Comment

                  • Duke W.
                    Beyond Control Poster
                    • January 1, 1993
                    • 15610

                    #10
                    Re: C2:67 37 Amp Alternator

                    "Upgrading" a 30-something amp Delcotron to 60-something amp output will not effect alternator drag torque at the same current load.

                    The Delcotron will only generate demanded current at system voltage, so if demand is 30 amps and the alternator can produce at least 30 amps at that speed, that's what it will generate even though it may be capable of 50 amps at the same speed.

                    A higher current rating just offers more reserve for worst case load condition, which is usually idle with all accessories on. If current demand exceeds alternator capacity at a given rotor speed, system voltage will drop below battery voltage, which is indicated by a discharge reading on the ammeter, so if you see a consistent discharge at idle with a heavy load (lights, AC, radio, etc) a higher output alternator may be necessary. If the installed alternator never or only rarely shows a discharge at idle, then it probably has enough capacity. The speed-output curve is fairly steep at low speed, so if the alternator appears to be maxxed out at idle, increasing idle speed by 50 to 100 RPM may do the trick.

                    Of course, the above assumes that the alternator is operating at design spec and doesn't have an internal problem such as an open diode.

                    Delcotrons are rated at 5000 rotor RPM (and the maximum speed spec is usually 18,000), which, depending on alternator drive ratio, will usually be in the range of 2000-2500 engine RPM. SHP engines which idle higher and rev higher typically have lower numerical drive ratios i.e. the alternator is turning slower at a given engine speed than a lower revving/idle speed medium performance engine.

                    My only concern is that the wiring of base alternators may not be designed to handle a higher current output alternator if its loaded to maximum output, but you can check schematics to be sure. If the base and high amp alternators use the same gage alternator and regulator wiring, then upgrading to the high amp stator should not cause any problems.

                    Duke

                    Comment

                    Working...

                    Debug Information

                    Searching...Please wait.
                    An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

                    Please push the back button and reload the previous window.'
                    An unexpected error was returned: 'Your submission could not be processed because the token has expired.

                    Please push the back button and reload the previous window.'
                    An internal error has occurred and the module cannot be displayed.
                    There are no results that meet this criteria.
                    Search Result for "|||"