Leaning Procedure for a Carbureted 182

[Jeffrey]

Greeting to all;



I own a 1964 Cessna 182 with a Continental O-470-R25 engine. This is
equipped with an E.I. 6 pt EGT gauge. Typical cruise power setting is 20"
manifold pressure 2300 RPM. I seem to have a plug fouling issue.



Can someone please give me the proper leaning procedure for both cruise
flight and ground operations (taxing)?



I'd really appreciate some experienced input. Thanks in advance!

Jeffrey

[RST Engineering]

Are you running 100LL or mogas?

Jim



> I own a 1964 Cessna 182 with a Continental O-470-R25 engine. This is
> equipped with an E.I. 6 pt EGT gauge. Typical cruise power setting is 20"
> manifold pressure 2300 RPM. I seem to have a plug fouling issue.

[Thomas Borchert]

Jeffrey,

> Typical cruise power setting is 20"
> manifold pressure 2300 RPM.

Wow! Why so low?


> Can someone please give me the proper leaning procedure for both cruise
> flight and ground operations (taxing)?
>

For taxi: lean right after start-up and stabilized RPM very aggresively
until a slight rise in RPM occurs. If you lean any further, the engine
should quit. The RPM rise should be around 25 RPM. If it is higher, have
your idle mixture adjusted. If you advance the throttle for the mag check,
the engine will stumble because it is so lean. That's GOOD because it
reminds you to enrichen again for take-off power. You cannot hurt the
engine by leaning at taxi power.

For flight: Lean whenever the power is below 75 percent. Lean until the
first cylinder peaks (that's not identical with the cylinder having the
highest EGT, it is the first cylinder whose EGT goes down again during
leaning). Then leave the mixture there if the engine runs smoothly or
enrichen until abojut 100 F rich of peak.

Have you read John Deakin's columns on engine management at www.avweb.com?

--
Thomas Borchert (EDDH)

[RST Engineering]

One reason and one reason only. With anything but a direct headwind, this
will get the fuel consumption down below 10 gallons of $3.50 fuel an hour.

Jim
20" and 2200.


"Thomas Borchert" > wrote in message
...
> Jeffrey,
>
>> Typical cruise power setting is 20"
>> manifold pressure 2300 RPM.
>
> Wow! Why so low?

[Thomas Borchert]

RST,

> One reason and one reason only. With anything but a direct headwind, this
> will get the fuel consumption down below 10 gallons of $3.50 fuel an hour.
>
> Jim
> 20" and 2200.
>

If it's any help, I'm paying 7.75. However, your trip time will be much
longer. You'll reach hour-based maintenance intervals sooner, too. Are you
sure you're saving money on this?

--
Thomas Borchert (EDDH)

[Jeffrey]

Running with 100LL.

"RST Engineering" > wrote in message
...
> Are you running 100LL or mogas?
>
> Jim
>
>
>
>> I own a 1964 Cessna 182 with a Continental O-470-R25 engine. This is
>> equipped with an E.I. 6 pt EGT gauge. Typical cruise power setting is 20"
>> manifold pressure 2300 RPM. I seem to have a plug fouling issue.
>
>

[Jeffrey]

Hi Thomas;

Well I didn't think it was too low a power setting. What do you prefer to
use?

As for Deakin's articles, I've not read them, thanks for the tip on that!
But which one should I start on?

Thanks again for the input!
Jeffrey

"Thomas Borchert" > wrote in message
...
> Jeffrey,
>
>> Typical cruise power setting is 20"
>> manifold pressure 2300 RPM.
>
> Wow! Why so low?
>
>
>> Can someone please give me the proper leaning procedure for both cruise
>> flight and ground operations (taxing)?
>>
>
> For taxi: lean right after start-up and stabilized RPM very aggresively
> until a slight rise in RPM occurs. If you lean any further, the engine
> should quit. The RPM rise should be around 25 RPM. If it is higher, have
> your idle mixture adjusted. If you advance the throttle for the mag check,
> the engine will stumble because it is so lean. That's GOOD because it
> reminds you to enrichen again for take-off power. You cannot hurt the
> engine by leaning at taxi power.
>
> For flight: Lean whenever the power is below 75 percent. Lean until the
> first cylinder peaks (that's not identical with the cylinder having the
> highest EGT, it is the first cylinder whose EGT goes down again during
> leaning). Then leave the mixture there if the engine runs smoothly or
> enrichen until abojut 100 F rich of peak.
>
> Have you read John Deakin's columns on engine management at www.avweb.com?
>
> --
> Thomas Borchert (EDDH)
>

[RST Engineering]

Then you will have plug fouling issues with the O-470 for the rest of your
airplane's life.

Jim


"Jeffrey" > wrote in message
. com...

> Running with 100LL.

[Scott Skylane]

RST Engineering wrote:

> Then you will have plug fouling issues with the O-470 for the rest of your
> airplane's life.

Bulls**t. I've put almost 500 exclusively 100LL hours on my O-470R with
nary a single plug fouled.

Happy Flying!
Scott Skylane
N92054

[Jeffrey]

What's your technique Scott?

"Scott Skylane" > wrote in message
...
> RST Engineering wrote:
>
>> Then you will have plug fouling issues with the O-470 for the rest of
>> your airplane's life.
>
> Bulls**t. I've put almost 500 exclusively 100LL hours on my O-470R with
> nary a single plug fouled.
>
> Happy Flying!
> Scott Skylane
> N92054

[Juan Jimenez]

TBO Advisor recommends the peak EGT method of leaning for the O-470 series
(except O-470-U), but it also warns that "In some engines, such as the
O-470-R, it may not be possible to operate smoothly at peak EGT (when EGT is
measured from a single probe that averages one bank of cylinders), since
mixture maldistribution can cause lean misfire to appear in the leanest
cylinders before peak EGT for the engine-as-a-whole has been reached." It
also says that running at peak EGT also means that detonation protection is
at its lowest.

What does your POH say? Continental does not recommend leaning to peak EGT
at settings above 65% power for normally-aspirated engines.

"Jeffrey" > wrote in message
. com...
> Greeting to all;
>
>
>
> I own a 1964 Cessna 182 with a Continental O-470-R25 engine. This is
> equipped with an E.I. 6 pt EGT gauge. Typical cruise power setting is 20"
> manifold pressure 2300 RPM. I seem to have a plug fouling issue.
>
>
>
> Can someone please give me the proper leaning procedure for both cruise
> flight and ground operations (taxing)?
>
>
>
> I'd really appreciate some experienced input. Thanks in advance!
>
> Jeffrey
>
>

[tony roberts]

In article >,
"Jeffrey" > wrote:

> What's your technique Scott?

Leeeaaaaannnn - on the ground until it almost quits,
and in the air - be aggressive - a cht/egt monitor helps! I recommend
ECI.

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE
>
> "Scott Skylane" > wrote in message
> ...
> > RST Engineering wrote:
> >
> >> Then you will have plug fouling issues with the O-470 for the rest of
> >> your airplane's life.
> >
> > Bulls**t. I've put almost 500 exclusively 100LL hours on my O-470R with
> > nary a single plug fouled.
> >
> > Happy Flying!
> > Scott Skylane
> > N92054

[Dale]

In article >,
Scott Skylane > wrote:

> RST Engineering wrote:
>
> > Then you will have plug fouling issues with the O-470 for the rest of your
> > airplane's life.
>
> Bulls**t. I've put almost 500 exclusively 100LL hours on my O-470R with
> nary a single plug fouled.

Same here....around 800 hours and no fouling problems.

Usually leaned on the ground. Leaned at cruise regardless of altitude.
Had an EI engine scanner/monitor with 6 leads EGT/CHT.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

[Scott Skylane]

Jeffrey wrote:

> What's your technique Scott?
>

Well it's a very detailed, scientifically validated protocol, and I'll
attempt to outline the specifics here:

For ground operation, I'll pull the mixture out, oh, about an inch and a
half or so, give or take.

Full rich for takeoff and climb, up to about 5000 ft or so (home base is
at sea level). Lean it a little for climbs above 5000 ft.

For cruise, pull the mixture out, oh, about an inch and a half or so,
give or take depending on altitude (pull out more at higher alt).

I have no engine monitor, so I used to pull the mix untill power loss,
then enrich slightly for cruise, but it always ended up in the same
place, so see above.

Thats it, as far as leaning goes. I cruise at 23 square, get about 150
mph on 12 gph.

I try to keep manifold pressure as high as possible. After takeoff, I
leave the throttle full, and pull back RPM to 2450. For power reduction
approaching the traffic pattern, I pull the RPM's down with the MP, down
to 2000 RPM and about 18" for pattern entry. My theory is, higher
combustion chamber pressures should help scavenge the lead better. This
theory is based on nothing but my gut.

Happy Flying!
Scott Skylane
N92054

[Thomas Borchert]

Jeffrey,

> Well I didn't think it was too low a power setting. What do you prefer to
> use?

75 percent as long as it's available, all that's there when not. And yes, it
could be too low a power setting influencing the scavenging process through
lower temps and pressures. But the main culprit is likely not enough leaning
on the ground.

> As for Deakin's articles, I've not read them, thanks for the tip on that!
> But which one should I start on?
>

There's a trio in succesion dealing with Mixture, Prop and Manifold
Pressure, IIRC. The latter is easy to recognize by its title, which is
"Manifold Pressure Sucks" (get it? - if not, you will after reading).
There's a general one dealing with engine management older than those. These
are the foundation. But basically, you'll be ok if you read all of them in
chronological order. It's a lot to read, but well worth it.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Juan,

> It
> also says that running at peak EGT also means that detonation protection is
> at its lowest.
>

Which is probably not so.

Some people have had good results with a little addition of carb heat to even
out the mixture distribution across cylinders, it seems.

--
Thomas Borchert (EDDH)

[tony roberts]

Hi Scott

Are you at Arlington this year?

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

> Happy Flying!
> Scott Skylane
> N92054

[Doug]

At power settings above 65% you need to be concerned about running too
lean, thus too hot. With monitoring all 6 cylinders it should be
possible to run 50 to 100 rich of peak at these high power settings.
You will have to lean until you hit peak, then richen. Use this EGT as
a guide. I would use 100 degrees rich of peak on power settings above
75%. This is on your hottest cylinder.

At power settings below 65%, you do not need to worry about running too
lean, so just lean until it runs rough and richen slightly. Note the
EGT on the hottest cylinder and use this EGT all the time.

Most of us pilots lean to a specific EGT. I use 1350, but I only have
one probe on one cylinder. The exact temperature varies with probe
installation. On my carb Lycoming 360, 1350 is all the way lean at 50%
power and maybe 100 degrees rich of peak at 75% power and 50 degrees
rich at 65% power. I have an engine that is well over TBO and still
going strong using this technique. One thing you can do is lean all the
way to roughness while at full throttle at 10,000' then richen till
smooth. Note the EGT and use this as a target setting at all power
settings. This will give you rich of peak at higher power settings and
all the way lean at 50% power.

You will read articles about running lean of peak, but most of this
only applies to engines with fuel injection and GAMI injectors. They
run these engines lean of peak at high power settings to help cooling
and fuel economy. It usually wont work with carbureted engines as you
will have uneven air and fuel distribution.

Lean on the ground for taxi as much as possible. Lean for takeoff at
airports above 3000'. Don't go full rich on landing unless landing at
airports below 3000'. Leaning for takeoff involves doing a runup and
leaning until you get an rpm drop, then richen 3 half turns on the
mixture knob. This works well. For landing, just lean to the takeoff
setting judging on how far out the mixture knob was set on takeoff.
This is all for airports above 3000'.

Hope that helps.

[Thomas Borchert]

Doug,

> At power settings above 65% you need to be concerned about running too
> lean, thus too hot.

Uhm, no, not at all. He'd have to be concerned to run not lean enough,
actually, since the temps decrease again when running leaner and leaner.
The point is: You have to worry to run at the right point in relation to
peak.

> With monitoring all 6 cylinders it should be
> possible to run 50 to 100 rich of peak at these high power settings.

50 rich is about the worst point to run at.

> Most of us pilots lean to a specific EGT.

Well, I sure don't. I don't know ANY other pilot (apart from you) who
does. Those numbers are completely irrelevant. The relation to peak is
key.

> I have an engine that is well over TBO and still
> going strong using this technique.

I can't see any curvature of the earth from the ground, so it must be
flat. Or, in other words: What proof do you have of a correlation?

>
> Lean on the ground for taxi as much as possible. Lean for takeoff at
> airports above 3000'.

Density altutide, not actual altitude, I'd like to add. VERY important!

--
Thomas Borchert (EDDH)

[[email protected]]

Jeffrey > wrote:
: I own a 1964 Cessna 182 with a Continental O-470-R25 engine. This is
: equipped with an E.I. 6 pt EGT gauge. Typical cruise power setting is 20"
: manifold pressure 2300 RPM. I seem to have a plug fouling issue.

: Can someone please give me the proper leaning procedure for both cruise
: flight and ground operations (taxing)?

I can't comment directly on the O-470 Cont in the 182 (My Cherokee has an O-360 180hp Lyc). I've read through as much
leaning info as I could get my hands on, and the Deakin articles on Avweb as others have suggested are the best around.
Bottom line:

- You cannot hurt the engine by *ANY* leaning below 65-75% power (depending on brand).
- You must run much richer than 50 ROP if above 75% At least 100 or more, or you very well may damage the engine.
- You will foul plugs if too rich for too long and/or not hot enough.
- CHT is what really determines if you have to run really rich or can run lean... as long 65-75% or less. If you're running
at 65% and you lean as far as you can (roughness) but your CHT's go above 400 (spark-plug type), you'd better not run there
for too long. Too hard on the jugs.

I would hazzard to say that if you're running 100LL in the 182, there is probably a huge detonation margin since the
octane rating is much more than necessary. You probably couldn't even *get* it to detonate at sea level full power if you
tried... not that'd I'd try it. If possible, run mogas in it for a cleaner, happier engine... unless you live where you can't
get alcohol-free gasoline. If you live there, move.


My personal procedures (which will be attacked by many as crazy) are as follows:
- Lean aggressively on the ground. Although it's difficult to get the mixture right since it changes when you throttle-jockey
for taxi, you want to run it so lean it's impossible to runup without stumbling. You can't hurt it on the ground, and you
can't forget to go full rich for takeoff. If you just lean it a little on the ground because you're worried about too lean,
you could takeoff with it leaned out that "safe inch or so"... which *ISN'T* safe for takeoff.
- Lean in a long climb to whatever EGT was at full-rich, low-altitude takeoff. On mine, peak EGT is 1550 or so, and full-rich
takeoff on a standard day is about 1400. I'll continuously pull the mixture in a long climb to hold 1400 degrees. If I get
high enough so full throttle is less than 70%, I'll lean to peak even in a climb so long as the CHT's don't go over 400.
- In cruise at 70% or less, lean as far as it will go and leave it there. Monitor CHT's and make sure it never gets over 400.

All my CHT temps are referenced to spark-plug probes. They read 50-75 degrees hotter than the cylinder barrel probes
(I've got one of those too and have verified it). If using those types, 350 would be my max comfortable, continuous cruise
CHT.

I've been running 93 A.K.I mogas in my 180 hp for about 250 hours now. Always clean plugs, very little combustion
chamber buildup, never fouled, etc, etc.

Flame on!
-Cory


--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[john smith]

Thomas Borchert wrote:
> Doug,

>>At power settings above 65% you need to be concerned about running too
>>lean, thus too hot.

> Uhm, no, not at all. He'd have to be concerned to run not lean enough,
> actually, since the temps decrease again when running leaner and leaner.
> The point is: You have to worry to run at the right point in relation to
> peak.

I don't fully agree with that. The O-470 is normally aspirated rather
than injected; without a tuned intake, the mixture arriving at each
cylinder is going to be more varied; it is likely that you may have one
or two cylinders lean, one or two cylinders rich and two cylinders in
the worst part of the pressure curve.

>>With monitoring all 6 cylinders it should be
>>possible to run 50 to 100 rich of peak at these high power settings.

> 50 rich is about the worst point to run at.

Yep, should be 100-150 rich.

>>Most of us pilots lean to a specific EGT.

> Well, I sure don't. I don't know ANY other pilot (apart from you) who
> does. Those numbers are completely irrelevant. The relation to peak is
> key.

The 182R I fly only has the single probe CHT that Cessna installed; lean
it until it is rough, then enrichen it a couple of twists.

>>I have an engine that is well over TBO and still
>>going strong using this technique.

> I can't see any curvature of the earth from the ground, so it must be
> flat. Or, in other words: What proof do you have of a correlation?

>>Lean on the ground for taxi as much as possible. Lean for takeoff at
>>airports above 3000'.

I lean to peak RPM with idle initially full rich at 900 RPM.

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Doug,
>
>> At power settings above 65% you need to be concerned about running too
>> lean, thus too hot.
>
> Uhm, no, not at all. He'd have to be concerned to run not lean enough,
> actually, since the temps decrease again when running leaner and leaner.
> The point is: You have to worry to run at the right point in relation to
> peak.

That's not what Continental says about their engine, and not what TBO
Advisor recommends.

Juan

[Matt Barrow]

"john smith" > wrote in message
.. .
> Thomas Borchert wrote:
> > Doug,
>
> >>At power settings above 65% you need to be concerned about running too
> >>lean, thus too hot.
>
> > Uhm, no, not at all. He'd have to be concerned to run not lean enough,
> > actually, since the temps decrease again when running leaner and leaner.
> > The point is: You have to worry to run at the right point in relation to
> > peak.
>
> I don't fully agree with that. The O-470 is normally aspirated rather
> than injected;

Umm...it's normally aspirated vs turbocharged; it's carbureted vs injected.

[Doug]

Yes, it is a carbureted engine. Leaning to peak at 50% power and then
using that temperature to lean to at higher power settings works. It
gives about 50 degrees rich at 65% power and 100 degrees rich at 75%
power and 150 degrees rich at 85% power etc. All without having to
actually lean to peak at these high power settings, which even one
time, can overheat and do damage.

All this talk about running lean of peak usually doesn't work with
carbureted engines because of uneven airflow. Running rich of peak
aviods the peak settings that can overheat things and do damage. It is
false economy to try and run lean AT HIGH POWER SETTINGS and possibly
damage your engine. Below 65% or so, you can usually lean all you want
and you will be fine. My method allows some "cushion" using the 50%
setting for lean as possible instead of 65%. I would not want to
advocate something that could cause damage, so I stayed conservative.
If you want to experiment around, you are free to do so. Just look in
your POH and see what 50%, 65% and 75% power settings are and jot those
down so you have a reference when you start experimenting. And don't
run things too hot. Heat weakens metal. That is what you want to avoid,
even if it means burning a little more fuel.

[john smith]

Doug,
Do you run high RPM/low MP or high MP/low RPM power settings at cruise?

[Doug]

I run my rpm at 2450, mainly because that is where it runs the
smoothest. Most of my local flights are at 20". I fly at 6500' MSL
locally (my airport is at 5300'). Cross country, I tend to run harder
going into the wind and throttle back a bit if I have a tailwind. But
if you want to save fuel, running at low rpm's and high manifold will
get you the most power with the least fuel and save wear on the engine
(fewer total revolutions). I've never heard an argument for different
leaning procedures with high rpm/low mp vs high mp/low rpm though.

My Husky's Lycoming carbureted 0-360A1P has 2200 tach time on it. No
oil burn, good compressions, no metal in the filter. I use Aeroshell
15-50 and change it every 50 hours (along with the filter). I have put
all but the first 250 hours on this since new engine. As I stated, I
lean to 1350 degrees EGT on my one probe. Been all over North America
in my bird. (Just got back from Quebec). Based in Colorado.

I think the main thing is to lean enough to get proper burn, but don't
lean so much as to burn things up. I have some friends with probes on
all cylinders and carbureted engines who have tried to run lean of peak
and they have mostly given up. Just doesn't work on carbureted engines.
It doesn't on mine. Most of Deacons stuff is applicable to fuel
injected, and ususually turbo charged engines being run at HIGH power
settings (like 80% power). It is a technique that uses a lean mixture
to keep things cool. Only works if you have fuel injection, gamis
probes on all cylinders and a fuel flow meter. I don't run that type of
equipment, so I can't really comment on it, though from what I hear, it
does work, if done properly. The guy that asked the question has
normally aspirated, carbureted engine.

[Frank Stutzman]

Doug > wrote:

> I think the main thing is to lean enough to get proper burn, but don't
> lean so much as to burn things up. I have some friends with probes on
> all cylinders and carbureted engines who have tried to run lean of peak
> and they have mostly given up. Just doesn't work on carbureted engines.

If you said "most" carbed engines, I probably wouldn't quibble. However,
it does work on some. It certainly works on my Continental E-225 with a
Bendix PS-5C carb. Its harder to do, but can be done and does work. Here
is what I had to do:

1) overhauled my carb and had it flow tested to make sure its doing its
job.
2) Pull off the throttle back a bit less than one inch. This put the carb
out of the enrichment mode that it is with full throttle. I think it may
also put a bit of turbulence into the airflow that helps the fuel
vaporization.
3) If I can't get smooth LOP operations with the above, I'll play a bit
with carb heat (which is actually alternate air on my plane). Causing the
induction air to be a few degrees warmer will often help get the
vaporization (and hence good distribution) needed.

I believe I've heard the GAMI folks say that getting good distribution is
easiest on the large Continentals. Something to do with the way
the stock induction is done.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

[Howard Nelson]

I fly a C182P with O470S. Recently read the engine management and leaning
articles on AVWEB prior to a long (1200NM) cross country. I have a 6
cylinder analyzer with CHT and EGT for each cylinder. Cruising at 7500ft I
would lean to about 75-100 ROP on the first cylinder to peak. I would have a
large descrepancy between EGT temps between the cylinders due to uneven
distribution of fuel air mixture in the O470S. I then tried a trick
mentioned in those articles. I would back off the throttle until MP just
noticably fell (about 1/4 inch MP). After a couple of minutes the EGT's were
all within 25 degrees of each other. The idea put forward in the article was
that by partially closing the throttle the turbulence created resulted in
more even distribution of fuel. Don't know if there is any rational basis of
this but seemed to work in my plane.

Howard

[Thomas Borchert]

Doug,

> Running rich of peak
> aviods the peak settings that can overheat things and do damage.

Not at all true. In fact, completely false. Sorry.

> It is
> false economy to try and run lean AT HIGH POWER SETTINGS and possibly
> damage your engine.
>

lean? How lean? This statement is not true.


--
Thomas Borchert (EDDH)

[Thomas Borchert]

John,

> > Uhm, no, not at all. He'd have to be concerned to run not lean enough,
> > actually, since the temps decrease again when running leaner and leaner.
> > The point is: You have to worry to run at the right point in relation to
> > peak.
>
> I don't fully agree with that. The O-470 is normally aspirated rather
> than injected; without a tuned intake, the mixture arriving at each
> cylinder is going to be more varied; it is likely that you may have one
> or two cylinders lean, one or two cylinders rich and two cylinders in
> the worst part of the pressure curve.
>

Not sure at what point we disagree.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Howard,

> After a couple of minutes the EGT's were
> all within 25 degrees of each other.
>

Just to make something clear about a common misunderstanding here: The
goal is NOT to have the EGTs equal. The goal is to have the EGTs in
equal distance from their respective peak. The absolute EGT value
doesn't matter.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Juan,

> That's not what Continental says about their engine, and not what TBO
> Advisor recommends.
>

Not sure what you mean. What part of the statement you quoted
Continental doesn't say?

--
Thomas Borchert (EDDH)

[Dave Butler]

Frank Stutzman wrote:

> 3) If I can't get smooth LOP operations with the above, I'll play a bit
> with carb heat (which is actually alternate air on my plane). Causing the
> induction air to be a few degrees warmer will often help get the
> vaporization (and hence good distribution) needed.

How does improving vaporization improve distribution?

[Ross Richardson]

One of the things I found with my O-360 and C/S prop is that at
altitudes where the MP falls off, generally to 22" - 23", I pull the
throttle back to see a slight decrease in the MP. Then I lean. I find I
get better fuel burn results and very near the Lycoming manual for this
engine. Leaving the throttle in full at high altitudes, tends to burn
more fuel and I am not sure I am getting anything out of it.

Comments?

Regards, Ross
C-172F 180HP
KSWI


Frank Stutzman wrote:
> Doug > wrote:
>
>
>>I think the main thing is to lean enough to get proper burn, but don't
>>lean so much as to burn things up. I have some friends with probes on
>>all cylinders and carbureted engines who have tried to run lean of peak
>>and they have mostly given up. Just doesn't work on carbureted engines.
>
>
> If you said "most" carbed engines, I probably wouldn't quibble. However,
> it does work on some. It certainly works on my Continental E-225 with a
> Bendix PS-5C carb. Its harder to do, but can be done and does work. Here
> is what I had to do:
>
> 1) overhauled my carb and had it flow tested to make sure its doing its
> job.
> 2) Pull off the throttle back a bit less than one inch. This put the carb
> out of the enrichment mode that it is with full throttle. I think it may
> also put a bit of turbulence into the airflow that helps the fuel
> vaporization.
> 3) If I can't get smooth LOP operations with the above, I'll play a bit
> with carb heat (which is actually alternate air on my plane). Causing the
> induction air to be a few degrees warmer will often help get the
> vaporization (and hence good distribution) needed.
>
> I believe I've heard the GAMI folks say that getting good distribution is
> easiest on the large Continentals. Something to do with the way
> the stock induction is done.
>
> --
> Frank Stutzman
> Bonanza N494B "Hula Girl"
> Hood River, OR
>

[Ross Richardson]

I should mention that I only have a single EGT probe on my engine. I
keep wondering if I should get an analyzer. So much I could buy...

Regards, Ross
C-172F 180HP
KSWI


Ross Richardson wrote:
> One of the things I found with my O-360 and C/S prop is that at
> altitudes where the MP falls off, generally to 22" - 23", I pull the
> throttle back to see a slight decrease in the MP. Then I lean. I find I
> get better fuel burn results and very near the Lycoming manual for this
> engine. Leaving the throttle in full at high altitudes, tends to burn
> more fuel and I am not sure I am getting anything out of it.
>
> Comments?
>
> Regards, Ross
> C-172F 180HP
> KSWI
>
>
> Frank Stutzman wrote:
>
>> Doug > wrote:
>>
>>
>>> I think the main thing is to lean enough to get proper burn, but don't
>>> lean so much as to burn things up. I have some friends with probes on
>>> all cylinders and carbureted engines who have tried to run lean of peak
>>> and they have mostly given up. Just doesn't work on carbureted engines.
>>
>>
>>
>> If you said "most" carbed engines, I probably wouldn't quibble. However,
>> it does work on some. It certainly works on my Continental E-225 with
>> a Bendix PS-5C carb. Its harder to do, but can be done and does
>> work. Here is what I had to do:
>>
>> 1) overhauled my carb and had it flow tested to make sure its doing
>> its job.
>> 2) Pull off the throttle back a bit less than one inch. This put the
>> carb out of the enrichment mode that it is with full throttle. I
>> think it may also put a bit of turbulence into the airflow that helps
>> the fuel vaporization.
>> 3) If I can't get smooth LOP operations with the above, I'll play a
>> bit with carb heat (which is actually alternate air on my plane).
>> Causing the induction air to be a few degrees warmer will often help
>> get the vaporization (and hence good distribution) needed.
>>
>> I believe I've heard the GAMI folks say that getting good distribution is
>> easiest on the large Continentals. Something to do with the way
>> the stock induction is done.
>>
>> -- Frank Stutzman
>> Bonanza N494B "Hula Girl"
>> Hood River, OR
>>

[Howard Nelson]

"Ross Richardson" > wrote in message
...
> I should mention that I only have a single EGT probe on my engine. I
> keep wondering if I should get an analyzer. So much I could buy...
>
> Regards, Ross
> C-172F 180HP
> KSWI
>
More than anything else I have added to the aircraft the cost of
installation and maintence of our Engine Analyzer was many times higher than
the the actual cost of the unit. Seems to be a high maintence item.

Howard

[Doug]

A couple of observations. If you are running rich of peak, you want ALL
they cylinders to be rich of peak and you use the leanest, highest temp
cylinder as your guide. If you are running lean of peak, you want all
the cylinders to be lean of peak, and you use the RICHEST, highest temp
cylinder as your guide. One can see why it is good to have all they
cylinders close to each other. This is what the Gami's do.

As for carb heat. If you put on the carb heat you introduce hot air,
which is less dense. You have just richened the mixture.

As for throttle pull back. If you lean to roughness, then pull back the
throttle, you have just richened the mixture.

There is no magic. You can safely operate at high power setting rich of
peak or lean of peak. To operate lean of peak you need (or want)
EGT/CHT monitoring of all cylinders, fuel injection, Gamis and fuel
flow monitoring to REALLY do it right. You MIGHT be able to operate
lean of peak successfully with a carbureted engine, but most can't
because of uneven air and fuel distribution.

If you operate at about 50% power you can run as lean as you want
because you won't be generating enough heat to do any damage. 65% power
takes 50 degrees rich (or lean), 75% takes 100 degrees rich (or lean),
85% 150 degrees rich (or lean) etc.

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Doug,
>
>> Running rich of peak
>> aviods the peak settings that can overheat things and do damage.
>
> Not at all true. In fact, completely false. Sorry.

Come on, Thomas. What in the world makes you think that the effects of heat
due to leaning to peak EGT at high power settings are NOT going to create
problems for the engine? This is common knowledge -- the closer your EGT
gets to 1600 degF for extended periods, the higher the chances your engine
will not reach or exceed TBO. Running at peak EGT at high power settings for
extended periods -will- have a negative effect on your engine. That's why
none of the manufacturers recommend doing this.

>> It is
>> false economy to try and run lean AT HIGH POWER SETTINGS and possibly
>> damage your engine.
>
> lean? How lean? This statement is not true.

No, it isn't. It's manufacturer recommendation.

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Juan,
>
>> That's not what Continental says about their engine, and not what TBO
>> Advisor recommends.
>>
>
> Not sure what you mean. What part of the statement you quoted
> Continental doesn't say?

Original message:

>> At power settings above 65% you need to be concerned about running too
>> lean, thus too hot.

Your reply:

> Uhm, no, not at all.

This is wrong. You DO have to be concerned about running too lean, which is
why Continental does not recommend leaning for extended periods of time at
high power settings (above 65%).

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
>
> Uhm, no, not at all. He'd have to be concerned to run not lean enough,
> actually, since the temps decrease again when running leaner and leaner.

....and the effects of increased oxidative attack on the exhaust negates the
so-called advantage of low temps. In addition, TBO advisor adds that "very
little cooling effect is coming from the fuel itself, so CHT does not
respond in quite the same way you'd expect." Running lean of peak also
results in reduced performance, rough engine operation in many cases and
shortened TBO due to the above-mentioned oxidative attack of exhaust and
combustion chamber components. Running lean of peak also has another side
effect, increase in oil acidity, which causes oxidation in engine internal
components (same thing happens if you don't operate the engine often enough
to burn off any condensation in the oil). At lean of peak, exhaust gases
are rich in oxides of nitrogen, which mix with moisture to create nitric
acid, which happens to be extremely corrosive. In addition, TBO Advisor says
there is direct evidence documenting a relationship between ntric acid and
camshaft wear. Because of this, they recommend that if you're going to
operate your engine at best economy mix, lean of peak, then change your oil
every 25 to 50 hours (preferably closer to 25). This method is specifically
not recommended for TSIO-360 series, O-470 and IO-470 series and several
other series and models of engines.

[Thomas Borchert]

Juan,

> Running lean of peak also
> results in reduced performance, rough engine operation in many cases and
> shortened TBO due to the above-mentioned oxidative attack of exhaust and
> combustion chamber components. Running lean of peak also has another side
> effect, increase in oil acidity, which causes oxidation in engine internal
> components (same thing happens if you don't operate the engine often enough
> to burn off any condensation in the oil).
>

Care to back these statements up with numbers?

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Juan,

> You DO have to be concerned about running too lean, which is
> why Continental does not recommend leaning for extended periods of time at
> high power settings (above 65%).
>

Ok, I'll try again. The point is to run at the right mixture setting. That
might be very rich of peak or lean of peak. Whichever you chose, "too lean"
is not the answer to "what's dangerous?".

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Juan,

> >
> >> Running rich of peak
> >> aviods the peak settings that can overheat things and do damage.
> >
> > Not at all true. In fact, completely false. Sorry.
>
> Come on, Thomas. What in the world makes you think that the effects of heat
> due to leaning to peak EGT at high power settings are NOT going to create
> problems for the engine? This is common knowledge -- the closer your EGT
> gets to 1600 degF for extended periods, the higher the chances your engine
> will not reach or exceed TBO.

The absolute worst place to run your engine with regard to extreme numbers
(temperatures AND pressures) is the 50 degree rich of peak area. That is in
direct contradiction to your statement above. And that's what my comment
referred to. The key temp to manage is cylinder head temp, not EGT.

> Running at peak EGT at high power settings for
> extended periods -will- have a negative effect on your engine. That's why
> none of the manufacturers recommend doing this.

Define "high". The manufacturer's absolutely do recomment running at peak EGT
at their recommended cruise power setting. They call that the "best economy"
setting.

--
Thomas Borchert (EDDH)

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Juan,
>
>> >
>> >> Running rich of peak
>> >> aviods the peak settings that can overheat things and do damage.
>> >
>> > Not at all true. In fact, completely false. Sorry.
>>
>> Come on, Thomas. What in the world makes you think that the effects of
>> heat
>> due to leaning to peak EGT at high power settings are NOT going to create
>> problems for the engine? This is common knowledge -- the closer your EGT
>> gets to 1600 degF for extended periods, the higher the chances your
>> engine
>> will not reach or exceed TBO.
>
> The absolute worst place to run your engine with regard to extreme numbers
> (temperatures AND pressures) is the 50 degree rich of peak area.

I never said the engine should be run 50 degrees rich of peak. You're the
one that's saying something totally different, that running lean of peak is
good for the engine, which it is not.

>> Running at peak EGT at high power settings for
>> extended periods -will- have a negative effect on your engine. That's why
>> none of the manufacturers recommend doing this.
>
> Define "high". The manufacturer's absolutely do recomment running at peak
> EGT
> at their recommended cruise power setting. They call that the "best
> economy"
> setting.

No, they do not. And if you want to play Clinton games, define "absolutely."
And RTFM the manual for the engine.

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Juan,
>
>> Running lean of peak also
>> results in reduced performance, rough engine operation in many cases and
>> shortened TBO due to the above-mentioned oxidative attack of exhaust and
>> combustion chamber components. Running lean of peak also has another side
>> effect, increase in oil acidity, which causes oxidation in engine
>> internal
>> components (same thing happens if you don't operate the engine often
>> enough
>> to burn off any condensation in the oil).
>>
>
> Care to back these statements up with numbers?

Don't need to, Kas Thomas and the manufacturers and engineers who analyze
this sort of thing already did. You got any evidence to the contrary other
than digital saliva, go ahead and show it. Get yourself a copy of 101+ Ways
to Extend The Life Of Your Engine and educate yourself, Thomas.

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Juan,
>
>> You DO have to be concerned about running too lean, which is
>> why Continental does not recommend leaning for extended periods of time
>> at
>> high power settings (above 65%).
>>
>
> Ok, I'll try again. The point is to run at the right mixture setting. That
> might be very rich of peak or lean of peak. Whichever you chose, "too
> lean"
> is not the answer to "what's dangerous?".

The context is a carbureted 182, an O-470. For the specific model mentioned
in this thread, neither the manufacturer nor TBO Advisor recommends running
lean of peak, period, or at peak EGT at power settings over 65%.

[Thomas Borchert]

Juan,

> You got any evidence to the contrary other
> than digital saliva, go ahead and show it.
>

http://www.gami.com/frames.htm

Your god is Kas Thomas. Mine isn't ;-)

--
Thomas Borchert (EDDH)

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
> Juan,
>
>> You got any evidence to the contrary other
>> than digital saliva, go ahead and show it.
>>
>
> http://www.gami.com/frames.htm
>
> Your god is Kas Thomas. Mine isn't ;-)

Then talk to your priest and switch bibles, kiddo, because the data on this
web does not support your assertions. It's not even close. Heck, you didn't
even bother to check to see if the engine that is the subject of this thread
is on the approved list for the GAMI products!

Sorry to shoot you down like that, but that's what happens when you don't do
your homework.

Juan

[Thomas Borchert]

Juan,

> Then talk to your priest and switch bibles, kiddo,

"Kiddo", huh? So now all you have left is to become condescending? Usenet is
just so much fun.

> because the data on this
> web does not support your assertions. It's not even close.

Guess you need reading lessons, kiddo (see, I can do it, too).

> Heck, you didn't
> even bother to check to see if the engine that is the subject of this thread
> is on the approved list for the GAMI products!

The subject of the thread went from a specific engine to general leaning
procedures real quick (read it). I NEVEr claimed that GAMIjectors were for
O-470s. The general principles still hold. And your claim of "richer is cooler"
is still not true.

>
> Sorry to shoot you down like that,

Excuse me?

--
Thomas Borchert (EDDH)

[Juan Jimenez]

"Thomas Borchert" > wrote in message
...
>
>> because the data on this
>> web does not support your assertions. It's not even close.
>
> Guess you need reading lessons, kiddo (see, I can do it, too).

But you can't back it up with facts, kiddo. I can. :)

>> Heck, you didn't
>> even bother to check to see if the engine that is the subject of this
>> thread
>> is on the approved list for the GAMI products!
>
> The subject of the thread went from a specific engine to general leaning
> procedures real quick (read it). I NEVEr claimed that GAMIjectors were for
> O-470s. The general principles still hold. And your claim of "richer is
> cooler"
> is still not true.

The subject of this thread never left the issue of leaning carbureted
engines before you started talking about LOP leaning. LOP is only for some
fuel injected engines, and only those with very exact fuel metering and the
right hardware to monitor what's going on in each cylinder. And now you're
saying I'm claiming richer is cooler? <chuckle> I had no idea you liked
musical chairs so much. I guess the shoe does fit.

>> Sorry to shoot you down like that,
>
> Excuse me?

Pick up your parachute before you leave the room. I made my point, I'm outta
here. :P

Juan

[Thomas Borchert]

Juan,

> I made my point
>

You did? To my eye, it looks more like you said "I'm right, you're
not", started the insults when I didn't agree and now just plain leave.
To you, that may be "making a point", to me it is kindergarten. But,
suit yourself.

PS: Still waiting for data on that acid theory of yours.

--
Thomas Borchert (EDDH)

[Darrel Toepfer]

Ross Richardson wrote:
> I should mention that I only have a single EGT probe on my engine. I
> keep wondering if I should get an analyzer. So much I could buy...
>
> Regards, Ross
> C-172F 180HP
> KSWI

Whose STC for the engine/prop upgrade? We just sold our 172F last week
with the original 0-300 on it...

Will pass the info on to the new owner if he's ever inclined to do so...

[Ross]

Darrel Toepfer wrote:
> Ross Richardson wrote:
>
>> I should mention that I only have a single EGT probe on my engine. I
>> keep wondering if I should get an analyzer. So much I could buy...
>>
>> Regards, Ross
>> C-172F 180HP
>> KSWI
>
>
> Whose STC for the engine/prop upgrade? We just sold our 172F last week
> with the original 0-300 on it...
>
> Will pass the info on to the new owner if he's ever inclined to do so...


I have the Doyn Conversion. While Barbara Williams owns the STC, I found
very little support when I had a question. I would go with Air Plains in
Oklahoma for any conversions. I really like mine especially with the
constant speed prop.

Ross

[Darrel Toepfer]

Ross wrote:
> Darrel Toepfer wrote:
>> Ross Richardson wrote:

>>> Regards, Ross
>>> C-172F 180HP
>>> KSWI
>
>> Whose STC for the engine/prop upgrade? We just sold our 172F last week
>> with the original 0-300 on it...
>>
>> Will pass the info on to the new owner if he's ever inclined to do so...
>
> I have the Doyn Conversion. While Barbara Williams owns the STC, I found
> very little support when I had a question. I would go with Air Plains in
> Oklahoma for any conversions. I really like mine especially with the
> constant speed prop.

Thanks...

[Frank Stutzman]

Juan Jimenez > wrote:

> The subject of this thread never left the issue of leaning carbureted
> engines before you started talking about LOP leaning. LOP is only for some
> fuel injected engines, and only those with very exact fuel metering and the
> right hardware to monitor what's going on in each cylinder.

I'll repeat my quibble I previously mentioned on this thread...

If you said most carbureted engines can't run LOP, then I would agree.

However, the Continental E-225 (with a Bendix PS-5C carburetor) in my
Bonanza will run LOP. While not a 0-470, its a pretty durn close
(virtually the same displacement). I do have a JPI with fuel flow on
this installation and would be happy to send anybody a download of a
flight demostrating this.

Also LOP operations were the standard airline procedure with the large
radials in DC-4/DC-6 days. Those were decidedly carbed engines.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR