Mailing List flyrotary@lancaironline.net Message #7667
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Re: Fw: Air Fuel Mixture Display
Date: Wed, 28 Apr 2004 13:30:21 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hi Richard,

    The extended range O2 sensors do overcome many of the limitations of the
current O2 sensor.  They have a more linear curve and are apparently more
sensitive and are therefore apparently more accurate.

   I have no experience with them as they are still quite expensive (over
$200).  For some  the increase accuracy might prove useful for testing, but
my personal opinion is for that  just adjusting the mixture the regular old
cheap O2 sensor does an adequate job.  Your engine of course does not know
nor care what AF ratio or LED is lit on your indicator, it only knows what
Air/Fuel ratio is getting through the intake.  I find the fuel flow meter is
a better indicator of engine performance.  For instance your mixture can be
rich at idle, mid range rpm or WOT all considerably different power outputs,
so an A/F by itself does not tell you all that much directly.  The
assumption is that if it is indicting rich then you have sufficient fuel
flow at that rpm to push the O2 sensor into the voltage indicating little
oxygen remaining after combustion.  But, if your fuel flow is 1.6 gph or16
GPH makes a BIG difference in power generated even though you might have the
same A/F indication with both rates.  But in one case your are producing
approx 18 HP and on the other end you could be producing  180HP.

   So if it were me, I would spend the money to get a fuel flow meter and
save by using the old (cheaper) O2 sensor.

But, again, for some testing the precision of the broad range O2 sensors
might be useful. Just a personal opinion of course.

FWIW

Ed


Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From: "Richard" <unicorn@gdsys.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, April 28, 2004 1:10 PM
Subject: [FlyRotary] Re: Fw: Air Fuel Mixture Display


> Hi Ed,
>
> Just read about an extended range O2 sensor in the Turbo Magazine. It is
> mentioned in connection with a mixture measuring gadget. Ever heard of
that?
> could this mean anything for our use? Or is it like any other O2 sensor.
> The gadget is offered by INNOVATE MOTORSPORTS.
>
> Richard Sohn
> N-2071U
> unicorn@gdsys.net
> www.gdsys.net/WWWmembers/unicorn/
>
> ----- Original Message -----
> From: "Ed Anderson" <eanderson@carolina.rr.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Wednesday, April 28, 2004 10:45 AM
> Subject: [FlyRotary] Fw: Air Fuel Mixture Display
>
>
> > Here is something that may be of interest to some of you.
> >
> > Ken and I have exchanged notes on our interest in electronic fuel
> monitoring
> > gadgets for the aircraft rotary.  Here is his interesting employment of
> the
> > LOG version of the LED indictor, to give a more linear response curve of
> the
> > O2 sensor.  As Ken indicated you are free to use this to build your own
or
> > contact him for a printed circuit board (don't know the cost, but
probably
> > well worth it).
> >
> > Ed
> > Ed Anderson
> > RV-6A N494BW Rotary Powered
> > Matthews, NC
> > ----- Original Message -----
> > From: "Ken Kelly" <ken7382@hotmail.com>
> > To: <eanderson@carolina.rr.com>
> > Sent: Wednesday, April 28, 2004 11:03 AM
> > Subject: Re: Air Fuel Mixture Display
> >
> >
> > > Hey Ed, here's our final schematic that we came up with.. along with
the
> > > bill of materials, and the AF response compared to the O2 sensor
output.
> > > Feel free to distribute them - we are not selling them, but will sell
> > > pre-made PC boards for anyone who is interested in making one. Bill
said
> > > he's had his running on his '84 Corvette and it runs GREAT!
> > >
> > > I also have a real nifty AFR meter from Australia that even has a
triple
> > > 7-segment that displays supposed AFR's on it, along with a small
> bargraph.
> > > It's PIC based, but pretty neat. I picked it up for $60 delivered to
the
> > US.
> > > But, it's DIY also, and the source code for the PIC is freeware. I
> haven't
> > > had a chance to build it yet, so I don't know if it works well or not.
> > >
> > > Ken
> > >
> > > _________________________________________________________________
> > > MSN Toolbar provides one-click access to Hotmail from any Web page -
> FREE
> > > download! http://toolbar.msn.com/go/onm00200413ave/direct/01/
> > >
> >
>
>
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