Loading ...
Sorry, an error occurred while loading the content.

Autogyro engine starts! / Tach wiring question

Expand Messages
  • Tom Curbishley
    Hello to the Group,Yesterday we started the engine for the first time on my friend s Bensen B8 autogyro. It s a Great Plains 1835 with a Vertex magneto and
    Message 1 of 3 , Aug 1, 2001
    • 0 Attachment
      Hello to the Group,

      Yesterday we started the engine for the first time on my friend's Bensen B8
      autogyro. It's a Great Plains 1835 with a Vertex magneto and dual
      Solex/Kadron carbs. It started on the second pull. :-)

      Without a pilot in the seat, the Bensen usually rests on its tailwheel.
      After the engine started, I walked around to the nose to check out
      instrumentation and to look for leaks. We nudged the throttle forward and
      the gyro sat right up on its nosewheel as if to say "Ok, I'm ready. Let's
      go!". What a thrill!

      Even though the aircraft belongs to my friend, I'm the "engine guy" on the
      project. And as such, I've had the pleasure to tinker with this fine VW
      powerplant, and to deal with the myriad issues involved with instrumenting
      it and mating it to the airframe. I've been having a blast.

      Now comes the first round of bug chasing, but the list so far is mercifully
      short. The engine quit at idle, the CHT gauges didn't show a reading
      (probably reversed wires), and the needle on the tach bounces all over the
      place.

      I could use some help with that last item. The tach is a Micro 1000 and I'm
      running it from the "P" lead on the magneto. The signal wire is a single,
      unshielded 18 AWG stranded wire. The Micro 1000 comes from Aircraft Spruce
      and is set to run with a pulse generator producing 4 pulses per crank
      revolution. The manufacturer assures me that the circuit will take just
      about any signal you give it, and that the above installation is fine. In
      fact, a prominent member of this list runs this tach from a 009 distributor
      with good results (Thanks for your help, Jim!). The "P" lead from the mag
      produces 4 pulses per rev, but the distributor shaft that drives it runs at
      1/2 crank speed, so I get 2 pulses per crank rev. There is an adjusting
      screw on the tach to compensate. We hooked up an electronic function
      generator and recalibrated the tach appropriately. But when the engine was
      running, the tach seemed to read high and very unsteadily, as if many extra
      pulses were creeping into the system. I've kept the signal wire well away
      from the spark plug wires, but it runs in the same bundle as the rest of
      the instrumentation wires to the instrument panel in the nose. What can I
      do to smooth out the reading? Shielded wire? Electronic filtration via
      resistor/capacitor? Any help would be appreciated.

      Tom Curbishley

      P.S. I've posted a couple of pictures in the Photos section of this list.
      Look for the "Bensen" album. http://photos.groups.yahoo.com/group/AirVW/lst
      If anyone is interested, I can post some more.

      _________________________________________________________
      Do You Yahoo!?
      Get your free @... address at http://mail.yahoo.com
    • James E. Hardy
      You know something you say here rings a bell. I remember when I tested mine on a local VW Bug, It indicated steady as a rock, and I calibrated it to my engine
      Message 2 of 3 , Aug 1, 2001
      • 0 Attachment
        You know something you say here rings a bell. I remember when I tested
        mine on a local VW Bug, It indicated steady as a rock, and I calibrated
        it to my engine test equipment, and the on board tach in the bug. But
        when I put it in the airplane, I've ended up having to adjust it back
        nearly 800rpm at full power, and at cruise, and higher rpm, it can jump
        around about 300 rpm or so. I have my signal wire bundled with all the
        rest to the engine compartment. This bundle carries the 12 volts for the
        coil, oil pressure capillary, grounds, and oil temp signal wire. Where
        my harness passes the firewall, it is very near the coil ignition wire
        to the distributor. I must have set myself up for all sorts of cross
        talk myself. Now as I recall, the installation kit came with a coil of
        wire shielding. . . . . .you think maybe I should have used it? jim

        Tom Curbishley wrote:

        > Hello to the Group,
        >
        > Yesterday we started the engine for the first time on my friend's Bensen B8
        > autogyro. It's a Great Plains 1835 with a Vertex magneto and dual
        > Solex/Kadron carbs. It started on the second pull. :-)
        >
        > Without a pilot in the seat, the Bensen usually rests on its tailwheel.
        > After the engine started, I walked around to the nose to check out
        > instrumentation and to look for leaks. We nudged the throttle forward and
        > the gyro sat right up on its nosewheel as if to say "Ok, I'm ready. Let's
        > go!". What a thrill!
        >
        > Even though the aircraft belongs to my friend, I'm the "engine guy" on the
        > project. And as such, I've had the pleasure to tinker with this fine VW
        > powerplant, and to deal with the myriad issues involved with instrumenting
        > it and mating it to the airframe. I've been having a blast.
        >
        > Now comes the first round of bug chasing, but the list so far is mercifully
        > short. The engine quit at idle, the CHT gauges didn't show a reading
        > (probably reversed wires), and the needle on the tach bounces all over the
        > place.
        >
        > I could use some help with that last item. The tach is a Micro 1000 and I'm
        > running it from the "P" lead on the magneto. The signal wire is a single,
        > unshielded 18 AWG stranded wire. The Micro 1000 comes from Aircraft Spruce
        > and is set to run with a pulse generator producing 4 pulses per crank
        > revolution. The manufacturer assures me that the circuit will take just
        > about any signal you give it, and that the above installation is fine. In
        > fact, a prominent member of this list runs this tach from a 009 distributor
        > with good results (Thanks for your help, Jim!). The "P" lead from the mag
        > produces 4 pulses per rev, but the distributor shaft that drives it runs at
        > 1/2 crank speed, so I get 2 pulses per crank rev. There is an adjusting
        > screw on the tach to compensate. We hooked up an electronic function
        > generator and recalibrated the tach appropriately. But when the engine was
        > running, the tach seemed to read high and very unsteadily, as if many extra
        > pulses were creeping into the system. I've kept the signal wire well away
        > from the spark plug wires, but it runs in the same bundle as the rest of
        > the instrumentation wires to the instrument panel in the nose. What can I
        > do to smooth out the reading? Shielded wire? Electronic filtration via
        > resistor/capacitor? Any help would be appreciated.
        >
        > Tom Curbishley
        >
        > P.S. I've posted a couple of pictures in the Photos section of this list.
        > Look for the "Bensen" album. http://photos.groups.yahoo.com/group/AirVW/lst
        > If anyone is interested, I can post some more.
        >
        > _________________________________________________________
        > Do You Yahoo!?
        > Get your free @... address at http://mail.yahoo.com
        >
        >
        >
        > To unsubscribe from this group, send an email to:
        > AirVW-unsubscribe@yahoogroups.com
        >
        >
        >
        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
        >
        >
        >
        >
      • Gary Gower
        Congratulations Tom, Great engine instalation, I also just started the engine (1/2 VW) with the new prop. also started easy, in the 3rd pull, sounds great!
        Message 3 of 3 , Aug 1, 2001
        • 0 Attachment
          Congratulations Tom,

          Great engine instalation, I also just started the
          engine (1/2 VW) with the new prop. also started easy,
          in the 3rd pull, sounds great! just kept it a little
          over idle. But until today I will hook up the Tach, is
          a Datcon that I bought from JC Whitney, will post
          later how it worked.

          Saludos
          Gary Gower

          --- Tom Curbishley <tomcurbishley@...> wrote:
          > Hello to the Group,
          >
          > Yesterday we started the engine for the first time
          > on my friend's Bensen B8
          > autogyro. It's a Great Plains 1835 with a Vertex
          > magneto and dual
          > Solex/Kadron carbs. It started on the second pull.
          > :-)
          >
          > Without a pilot in the seat, the Bensen usually
          > rests on its tailwheel.
          > After the engine started, I walked around to the
          > nose to check out
          > instrumentation and to look for leaks. We nudged the
          > throttle forward and
          > the gyro sat right up on its nosewheel as if to say
          > "Ok, I'm ready. Let's
          > go!". What a thrill!
          >
          > Even though the aircraft belongs to my friend, I'm
          > the "engine guy" on the
          > project. And as such, I've had the pleasure to
          > tinker with this fine VW
          > powerplant, and to deal with the myriad issues
          > involved with instrumenting
          > it and mating it to the airframe. I've been having a
          > blast.
          >
          > Now comes the first round of bug chasing, but the
          > list so far is mercifully
          > short. The engine quit at idle, the CHT gauges
          > didn't show a reading
          > (probably reversed wires), and the needle on the
          > tach bounces all over the
          > place.
          >
          > I could use some help with that last item. The tach
          > is a Micro 1000 and I'm
          > running it from the "P" lead on the magneto. The
          > signal wire is a single,
          > unshielded 18 AWG stranded wire. The Micro 1000
          > comes from Aircraft Spruce
          > and is set to run with a pulse generator producing 4
          > pulses per crank
          > revolution. The manufacturer assures me that the
          > circuit will take just
          > about any signal you give it, and that the above
          > installation is fine. In
          > fact, a prominent member of this list runs this tach
          > from a 009 distributor
          > with good results (Thanks for your help, Jim!). The
          > "P" lead from the mag
          > produces 4 pulses per rev, but the distributor shaft
          > that drives it runs at
          > 1/2 crank speed, so I get 2 pulses per crank rev.
          > There is an adjusting
          > screw on the tach to compensate. We hooked up an
          > electronic function
          > generator and recalibrated the tach appropriately.
          > But when the engine was
          > running, the tach seemed to read high and very
          > unsteadily, as if many extra
          > pulses were creeping into the system. I've kept the
          > signal wire well away
          > from the spark plug wires, but it runs in the same
          > bundle as the rest of
          > the instrumentation wires to the instrument panel in
          > the nose. What can I
          > do to smooth out the reading? Shielded wire?
          > Electronic filtration via
          > resistor/capacitor? Any help would be appreciated.
          >
          > Tom Curbishley
          >
          > P.S. I've posted a couple of pictures in the Photos
          > section of this list.
          > Look for the "Bensen" album.
          > http://photos.groups.yahoo.com/group/AirVW/lst
          > If anyone is interested, I can post some more.
          >
          >
          _________________________________________________________
          > Do You Yahoo!?
          > Get your free @... address at
          > http://mail.yahoo.com
          >
          >
          > ------------------------ Yahoo! Groups Sponsor
          >
          > To unsubscribe from this group, send an email to:
          > AirVW-unsubscribe@yahoogroups.com
          >
          >
          >
          > Your use of Yahoo! Groups is subject to
          > http://docs.yahoo.com/info/terms/
          >
          >


          __________________________________________________
          Do You Yahoo!?
          Make international calls for as low as $.04/minute with Yahoo! Messenger
          http://phonecard.yahoo.com/
        Your message has been successfully submitted and would be delivered to recipients shortly.