REFLECTOR:FADEC info

Jim Sower reflector@tvbf.org
Sun, 21 Dec 2003 09:14:01 -0600


Exactly.  In the automotive conversion world, besides from having a far superior long
block, you can duplex EVERYTHING for, basically, pocket change (compared to the cost
of a mag or set of Lyc plugs).  Everything about them is better than anything
certified except for the peripheral growing pains which are a temporary situation.

Dennis Martin wrote:

> My Electromotive FADEC (for Chevy V-6 odd fire engine) has EGT failure
> mode backup - engine automatically goes into limp home mode if any one
> of the sensors goes south.  I also have two magnetic hall sensors, one
> for each bank of cylinders.  If one goes out, I'll run a bit rough, but
> can still limp home with half of the pistons still firing.  Same for
> six-pack set of coils.  If one goes out (or a bank of three goes out),
> I still have a back-up set of coils.  Nothing's fail-safe, but this is
> how they designed the computer.  I'm installing two computers, just in
> case.
>
> Dennis Martin
>
> On Saturday, December 20, 2003, at 04:31 PM, Jim Sower wrote:
>
> > <... safe to say that (probably) all of the gotcha scenarios have been
> > addressed ...>
> > That's comforting.  I had hoped that my questions were specific enough
> > to warrant
> > specific answers.  I think it would be interesting to know, if EGTs
> > were driving fuel
> > delivery, how they address failure modes such as gradual deterioration
> > (inaccurate
> > output) of the probes and how one might go about distinguishing
> > between a
> > deteriorating EGT probe and a deteriorating something else (like
> > cylinder) that has a
> > similar effect on EGT.
> >
> > But then again, my questions were somewhat rhetorical.  I am much more
> > interested in
> > auto conversions for a variety of reasons not least of which is that I
> > am not in a
> > position to spend what FADEC costs.  Seems to me that spending all
> > those thousands of
> > $ to put a "modern" face on an anachronistic Lyc is an exercise in
> > trying to make a
> > silk purse out of a sow's ear.
> >
> > Will it be as reliable and accurate as late model automotive fuel
> > controls? ... Jim S.
> >
> > Wayne Lanza wrote:
> >
> >> Hi Jim,
> >>   If you haven't been made aware of the Aerosance web site - here ya
> >> go...
> >> I worked closely for a week with the designers of the system while
> >> installing
> >> the Continental FADEC system in Velocity's XL Dash 5 demonstrator
> >> aircraft.
> >> They have designed many failure mode operations into the system, safe
> >> to
> >> say that (probably) all of the gotcha scenarios have been addressed.
> >>
> >> Have a Great Holiday,
> >> Wayne Lanza
> >> Composite Design
> >>
> >> goto the Aerosance web page at - http://www.FADEC.com
> >> ________________________________________________________________
> >>
> >> On Thursday, December 18, 2003, at 11:16 PM, Jim Sower wrote:
> >>
> >>> I need some help with some specifics on how FADEC works.
> >>> <... FADEC system meters the fuel-air mixture to ... power ... 100
> >>> degrees Rich of
> >>> peak ... cruise ... 100 degrees Lean of peak ...>
> >>>
> >>> Is it safe to assume that this FADEC feature is driven by EGT
> >>> sensors?
> >>>
> >>> Is it further safe to assume that FADEC varies fuel delivery from one
> >>> cylinder to
> >>> another according to individual EGTs (which of course are caused by
> >>> uneven air
> >>> delivery through the non symmetric intake runners)?
> >>>
> >>> IIRC, EGT probes tend to fail by degrees, giving increasingly
> >>> erroneous readings for a
> >>> while until they quit altogether.  How does FADEC [allege?] to deal
> >>> with partial
> >>> failures of EGT probe?  Total failure?
> >>>
> >>> Inquiring minds need to know .... Jim S.
> >>
> >> _______________________________________________
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> >
> > --
> > Jim Sower
> > Crossville, TN; Chapter 5
> > Long-EZ N83RT, Velocity N4095T
> >
> >
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>
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--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T