O2 sensor?

Saw this posted to the Lycoming group, and it sounds like a pretty good idea. Anybody heard of it?

"A friend flying an IO-360 powered Glasair installed an oxygen sensor
system that has an panel mounted indicator light to show when balanced
combustion is reached. He simply adjusts mixture until the light comes
on and knows he has complete combustion (his theory is that EGT is
really just a good guess). He has had very good results from this
system in terms of fuel economy and performance.

I believe he purchased the system from Wag a few years ago. As I
recall it was for experimentals only. They do not currently list such
a system in their catalog. I have not found one at ACS&S or Chief either."

"Blueskies" wrote

"A friend flying an IO-360 powered Glasair installed an oxygen sensor
system that has an panel mounted indicator light to show when balanced
combustion is reached. He simply adjusts mixture until the light comes
on and knows he has complete combustion (his theory is that EGT is
really just a good guess). He has had very good results from this
system in terms of fuel economy and performance.

How does it deal with the lead fouling issue?

I had always thought that Oxy sensors were only used while the engine was at
low power settings, and that once it was cranked up to full power, the
engines ran in a closed loop system, ignoring the Oxy sensor. I would think
a mass airflow sensor, and a programmed controller to set the mixture to the
ideal settings would be more useful.

I would be interested in seeing how much the mixture was changed, with the
advice of the Oxy sensor setup.

I have to admit that it does sound interesting.
--
Jim in NC

("Morgans" wrote)
I had always thought that Oxy sensors were only used while the engine was
at low power settings, and that once it was cranked up to full power, the
engines ran in a closed loop system, ignoring the Oxy sensor.


My reading of his post suggests it's a "monitor only" O2 sensor. With the
data from the O2 sensor, the pilot then controls the mixture manually.


Montblack

"Morgans" wrote in message
...

"Blueskies" wrote

"A friend flying an IO-360 powered Glasair installed an oxygen sensor
system that has an panel mounted indicator light to show when balanced
combustion is reached. He simply adjusts mixture until the light comes
on and knows he has complete combustion (his theory is that EGT is
really just a good guess). He has had very good results from this
system in terms of fuel economy and performance.

How does it deal with the lead fouling issue?

I had always thought that Oxy sensors were only used while the engine was
at low power settings, and that once it was cranked up to full power, the
engines ran in a closed loop system, ignoring the Oxy sensor. I would
think a mass airflow sensor, and a programmed controller to set the
mixture to the ideal settings would be more useful.

I would be interested in seeing how much the mixture was changed, with the
advice of the Oxy sensor setup.


Yes, lead would be a problem - the sensor won't last long with av-gas.

You can run closed loop at most loads (depending on the type of sensor, you
can run closed loop even when you want to run rich for power)

For the most common sensor, the output "switches" as you pass through the
chemically correct mixture of air and fuel - but you get best economy at air
fuel ratios leaner than that...

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

On Jul 2, 6:52 pm, "Morgans" wrote:
"Blueskies" wrote

"A friend flying an IO-360 powered Glasair installed an oxygen sensor
system that has an panel mounted indicator light to show when balanced
combustion is reached. He simply adjusts mixture until the light comes
on and knows he has complete combustion (his theory is that EGT is
really just a good guess). He has had very good results from this
system in terms of fuel economy and performance.

How does it deal with the lead fouling issue?

I had always thought that Oxy sensors were only used while the engine was at
low power settings, and that once it was cranked up to full power, the
engines ran in a closed loop system, ignoring the Oxy sensor. I would think
a mass airflow sensor, and a programmed controller to set the mixture to the
ideal settings would be more useful.

I would be interested in seeing how much the mixture was changed, with the
advice of the Oxy sensor setup.

I have to admit that it does sound interesting.
--
Jim in NC

Jim,
You have it backwards. EFI uses pre-programmed settings until the
engine reaches operating temperature. Then the system enters "closed
loop mode" and uses output from the O2 sensor to provide "fuel trim"
data which offsets the preprogrammed values for minimum emissions.
Some later model cars have electrically heated O2 sensors to allow for
closed loop mode quicker (EPA lower emission requirements).

When used with 100LL the O2 sensor will slowly become contaminated
and cease to work.

Gary also in NC

"Montblack" wrote

My reading of his post suggests it's a "monitor only" O2 sensor. With the
data from the O2 sensor, the pilot then controls the mixture manually.

I understood that to be the case also.

My point is that in auto systems, the oxy sensor information must not be
very valuable, since the computer ignores it at high power, which is where
this system is attempting to function.

Would the sensor/monitor have very much positive benefit, is my question.
--
Jim in NC

"Gary" wrote

Jim,
You have it backwards. EFI uses pre-programmed settings until the
engine reaches operating temperature. Then the system enters "closed
loop mode" and uses output from the O2 sensor to provide "fuel trim"
data which offsets the preprogrammed values for minimum emissions.
Some later model cars have electrically heated O2 sensors to allow for
closed loop mode quicker (EPA lower emission requirements).

Do you know of any web pages that discuss this type of thing? I would like
to read more.
--
Jim in NC

"Gary" wrote in message
ps.com...
On Jul 2, 6:52 pm, "Morgans" wrote:
"Blueskies" wrote

"A friend flying an IO-360 powered Glasair installed an oxygen sensor
system that has an panel mounted indicator light to show when balanced
combustion is reached. He simply adjusts mixture until the light comes
on and knows he has complete combustion (his theory is that EGT is
really just a good guess). He has had very good results from this
system in terms of fuel economy and performance.

How does it deal with the lead fouling issue?

I had always thought that Oxy sensors were only used while the engine
was at
low power settings, and that once it was cranked up to full power, the
engines ran in a closed loop system, ignoring the Oxy sensor. I would
think
a mass airflow sensor, and a programmed controller to set the mixture to
the
ideal settings would be more useful.

I would be interested in seeing how much the mixture was changed, with
the
advice of the Oxy sensor setup.

I have to admit that it does sound interesting.
--
Jim in NC

Jim,
You have it backwards. EFI uses pre-programmed settings until the
engine reaches operating temperature. Then the system enters "closed
loop mode" and uses output from the O2 sensor to provide "fuel trim"
data which offsets the preprogrammed values for minimum emissions.
Some later model cars have electrically heated O2 sensors to allow for
closed loop mode quicker (EPA lower emission requirements).

When used with 100LL the O2 sensor will slowly become contaminated
and cease to work.

Gary also in NC

I have been told that they slow down, but may not cease to work in the
absolute sense. In other works, they will become useless for the closed
loop control that an automotive ECM requires, but might remain quite useable
in the manner that a pilot might use them. As to a comparison between an O2
sensor and EGT, I just don't know; but I am quite curious.

BTW, it is probably usefull to think of the Open Loop Mode of the automotive
ECM at Wide Open Throttle as being analogous to the enrichment valve feature
of an aircraft carburetor. As soom as you no longer tramp the accelerator
firmly to the floor, the ECM will return to best economy (or possibly least
emissions) mixture--at least that is the impression which I received from
the limited litterature I read.

Peter
(Awaiting correction from any with real bench experience.)

"Peter Dohm" wrote in message
...
... BTW, it is probably usefull to think of the Open Loop Mode of the
automotive
ECM at Wide Open Throttle as being analogous to the enrichment valve
feature
of an aircraft carburetor. As soom as you no longer tramp the accelerator
firmly to the floor, the ECM will return to best economy (or possibly
least
emissions) mixture--at least that is the impression which I received from
the limited litterature I read.


Least emissions - it's all about the care and feeding of the three way
catalyst (Oxidizes CO and unburned HC, Reduces NOx (NO and NO2)). At best
economy (lean), the catalyst can't reduce the NOx.

With a wide band (or "universal") oxygen sensor, you can stay closed loop
even during power (or catalyst temperature protection) enrichment - but
those sensor cost $15-$20 more (at OEM prices) so they are less common.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Peter Dohm wrote:
I have been told that they slow down, but may not cease to work in the
absolute sense. In other works, they will become useless for the closed
loop control that an automotive ECM requires, but might remain quite useable
in the manner that a pilot might use them. As to a comparison between an O2
sensor and EGT, I just don't know; but I am quite curious.


Ed Anderson runs a rotary in his RV-6 and uses 100LL exclusively. This
is his experience. The O2 sensor is useless for driving an ECM, but
still responds faster than he can.

emissions) mixture--at least that is the impression which I received from
the limited litterature I read.


Do a Google search on Megasquirt (I just finished building one. Doing
the burn-in test right now). You'll get more data on how ECM, O2
sensors, electronic ignition, etc all work than you'll ever need to know.