Constant speed props [Archive]

C J Campbell

June 24th 04, 04:22 PM

"EDR" > wrote in message
...
> In article >, GE
> > wrote:
>
> > I'm taking delivery today of my first aircraft and it had a constant
speed
> > prop. I have only flown fixed props thus far. I want to have as much
> > understanding of the c-s prop as possible before I get with my
instructor. I
> > understand the basic difference in what the controls do, but I don't
really
> > have a good understanding of the hows and whys of flying with them. Any
> > general information, explanations, and tips would be greatly
appreciated.
>
> Go to www.avweb.com
> on the left side of the screen, select COLUMNS
> scroll down to find THE PELICAN"S PERCH
> there are articles on fuel injection, manifold pressure, constant speed
> props, leaning, etc
> Everything you ever want to know about operating a high performance
> aircraft engine is in those articles.

While I would agree that John Deakin is worth reading, people who are new to
high performance engines and constant speed propellers should be aware that
Deakin has many views that are highly controversial, to say the least,
especially when it comes to his religious crusade to get everyone to run
their engines lean of peak (which, of course, has spawned a full-scale
counter-reformation movement that tries to get everyone to run their engines
rich of peak).

EDR will eventually be converted to one side or the other and will run his
own airplane the way he sees fit, much to the disgust of those pilots that
will think he has gone over to the dark side.

If you are renting an airplane, though, run it the way the owner/operator
wants it treated, which is invariably in accordance with the manufacturer's
operating instructions.

Greg Copeland

June 24th 04, 04:23 PM

On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:

> In article >, GE
> > wrote:
>
>> I'm taking delivery today of my first aircraft and it had a constant speed
>> prop. I have only flown fixed props thus far. I want to have as much
>> understanding of the c-s prop as possible before I get with my instructor. I
>> understand the basic difference in what the controls do, but I don't really
>> have a good understanding of the hows and whys of flying with them. Any
>> general information, explanations, and tips would be greatly appreciated.
>
> Go to www.avweb.com
> on the left side of the screen, select COLUMNS
> scroll down to find THE PELICAN"S PERCH
> there are articles on fuel injection, manifold pressure, constant speed
> props, leaning, etc
> Everything you ever want to know about operating a high performance
> aircraft engine is in those articles.

Great link!

I started reading this
article, http://www.avweb.com/news/columns/186619-1.html, and have a
question. In the Runup section, when he starts to test for proper mag
operation, somethings seems odd there. Can someone help explain that? He
says, "Are the mags working? The leaner the mixture, the more mag drop
you'll see on one mag, and that's normal." He then goes on to say, "The
EGTs should rise on the first single-mag operation, stay there for the
second, then drop again on the return to BOTH. That rise is proof-positive
the entire ignition system is working, and working well, and the leaner
the mixture, the more diagnostic it is."

Can someone help explain the supporting logic there? If both mags are
working properly and you switch to a single mag, why would the EGT go up?
After all, in theory, you're producing less spark and thusly, a slightly
less effecient ignition of the fuel/air. I would of thought that EGT
would stay the same or go down *just slightly* when running off of one
mag. Likewise, if one mag is not working, I would fully expect to see a
big EGT drop for the given problematic mag, which he does agree with.
But, he further asserts that, "If any of them fail to rise or even drop
during single-mag operation, there is a problem with that plug, the wire,
or the mag."

So, why would running on one mag, versus two, always cause higher EGTs?
And why would no rise in EGT indicate a bad mag, wire or plug?

Anyone?

P.S. I cross posted because this seems like good student pilot material
too.

Greg Copeland

June 24th 04, 04:28 PM

On Thu, 24 Jun 2004 08:22:05 -0700, C J Campbell wrote:

>
> "EDR" > wrote in message
> ...
>> In article >, GE
>> > wrote:
>>
>> > I'm taking delivery today of my first aircraft and it had a constant
> speed
>> > prop. I have only flown fixed props thus far. I want to have as much
>> > understanding of the c-s prop as possible before I get with my
> instructor. I
>> > understand the basic difference in what the controls do, but I don't
> really
>> > have a good understanding of the hows and whys of flying with them. Any
>> > general information, explanations, and tips would be greatly
> appreciated.
>>
>> Go to www.avweb.com
>> on the left side of the screen, select COLUMNS
>> scroll down to find THE PELICAN"S PERCH
>> there are articles on fuel injection, manifold pressure, constant speed
>> props, leaning, etc
>> Everything you ever want to know about operating a high performance
>> aircraft engine is in those articles.
>
> While I would agree that John Deakin is worth reading, people who are new to
> high performance engines and constant speed propellers should be aware that
> Deakin has many views that are highly controversial, to say the least,
> especially when it comes to his religious crusade to get everyone to run
> their engines lean of peak (which, of course, has spawned a full-scale
> counter-reformation movement that tries to get everyone to run their engines
> rich of peak).
>
> EDR will eventually be converted to one side or the other and will run his
> own airplane the way he sees fit, much to the disgust of those pilots that
> will think he has gone over to the dark side.
>
> If you are renting an airplane, though, run it the way the owner/operator
> wants it treated, which is invariably in accordance with the manufacturer's
> operating instructions.

Timely posting! That was going to be my next post. It bothered me how
lean he was suggesting the engine should be run. I guess that answers
that. ;)

As usual, great advice!

Cheers!

Tom Sixkiller

June 24th 04, 04:36 PM

"C J Campbell" > wrote in message
...
> While I would agree that John Deakin is worth reading, people who are new
to
> high performance engines and constant speed propellers should be aware
that
> Deakin has many views that are highly controversial, to say the least,

Does her or doesn't he provide copious data to support his position, and
doesn't he also provide copious data to show that it's the contrary postion
that's full of it?

> especially when it comes to his religious crusade to get everyone to run
> their engines lean of peak (which, of course, has spawned a full-scale
> counter-reformation movement that tries to get everyone to run their
engines
> rich of peak).

See above.

Roger Hamlett

June 24th 04, 04:41 PM

"Greg Copeland" > wrote in message
...
> On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:
>
> > In article >, GE
> > > wrote:
> >
> >> I'm taking delivery today of my first aircraft and it had a constant
speed
> >> prop. I have only flown fixed props thus far. I want to have as much
> >> understanding of the c-s prop as possible before I get with my
instructor. I
> >> understand the basic difference in what the controls do, but I don't
really
> >> have a good understanding of the hows and whys of flying with them. Any
> >> general information, explanations, and tips would be greatly
appreciated.
> >
> > Go to www.avweb.com
> > on the left side of the screen, select COLUMNS
> > scroll down to find THE PELICAN"S PERCH
> > there are articles on fuel injection, manifold pressure, constant speed
> > props, leaning, etc
> > Everything you ever want to know about operating a high performance
> > aircraft engine is in those articles.
>
>
> Great link!
>
> I started reading this
> article, http://www.avweb.com/news/columns/186619-1.html, and have a
> question. In the Runup section, when he starts to test for proper mag
> operation, somethings seems odd there. Can someone help explain that? He
> says, "Are the mags working? The leaner the mixture, the more mag drop
> you'll see on one mag, and that's normal." He then goes on to say, "The
> EGTs should rise on the first single-mag operation, stay there for the
> second, then drop again on the return to BOTH. That rise is proof-positive
> the entire ignition system is working, and working well, and the leaner
> the mixture, the more diagnostic it is."
>
> Can someone help explain the supporting logic there? If both mags are
> working properly and you switch to a single mag, why would the EGT go up?
> After all, in theory, you're producing less spark and thusly, a slightly
> less effecient ignition of the fuel/air. I would of thought that EGT
> would stay the same or go down *just slightly* when running off of one
> mag. Likewise, if one mag is not working, I would fully expect to see a
> big EGT drop for the given problematic mag, which he does agree with.
> But, he further asserts that, "If any of them fail to rise or even drop
> during single-mag operation, there is a problem with that plug, the wire,
> or the mag."
>
> So, why would running on one mag, versus two, always cause higher EGTs?
> And why would no rise in EGT indicate a bad mag, wire or plug?
>
> Anyone?
>
>
> P.S. I cross posted because this seems like good student pilot material
> too.
The key is that with two plugs, the combustion _in the cylinder_ is more
complete, earlier. When one mag cuts, the fuel air mixture still fully
burns, but the burn is continued slightly latter (where it does less work on
the piston). This results in the gas coming out of the exhaust being a
little hotter (in some cases, it may even be still burning).

Best Wishes

C J Campbell

June 24th 04, 04:55 PM

I think Deakin is worth reading, but some of what he says should be taken
with a grain of salt. His columns are mostly based on experiments with his
own highly modified Bonanza, a few high performance radial engines, and some
theory. In fact, a careful reading of his columns will show no test data for
the most common engine and propeller combinations in use today. The reasons
for this are fairly simple -- few airplanes have the instrumentation that
Deakin needs to test his theories. This is why Deakin's theories for running
lean of peak remain a minority view. Granted, it is a very noisy minority,
but remember that it is also a small minority. I think they have a point.
They may even be right. But they don't have nearly the evidence that they
think they have.

Deakin's remarks are mostly pertinent to running TCM engines, which are much
different than engines from other manufacturers. Not to put too fine a point
on it, some TCM engines are the only ones I know of that so consistently
develop cracks that the most part of an annual inspection basically consists
of measuring and cataloging the spread of these cracks. The engine used in
the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for example.

Barring solid data to the contrary (and Deakin, remember, does not give you
solid data -- he only appears to do that), your airplane should be operated
in accordance with the manufacturer's recommendations. This will ensure that
you maintain your insurance coverage, if nothing else.

Keeping all that in mind, Deakin's columns are still probably the best
exposition on how to use a constant speed propeller. You will note right
away that everything is about power and performance. A fair number of people
think it is also about fuel economy, but that is at best a secondary
consideration. Fuel economy is a natural result of getting maximum power for
your fuel burn, but if that were really the goal there would be no
turbocharged engines.

Greg Copeland

June 24th 04, 04:55 PM

On Thu, 24 Jun 2004 16:41:32 +0100, Roger Hamlett wrote:

>
> "Greg Copeland" > wrote in message
> ...
>> On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:
>>
>> > In article >, GE
>> > > wrote:
>> >
>> >> I'm taking delivery today of my first aircraft and it had a constant
> speed
>> >> prop. I have only flown fixed props thus far. I want to have as much
>> >> understanding of the c-s prop as possible before I get with my
> instructor. I
>> >> understand the basic difference in what the controls do, but I don't
> really
>> >> have a good understanding of the hows and whys of flying with them. Any
>> >> general information, explanations, and tips would be greatly
> appreciated.
>> >
>> > Go to www.avweb.com
>> > on the left side of the screen, select COLUMNS
>> > scroll down to find THE PELICAN"S PERCH
>> > there are articles on fuel injection, manifold pressure, constant speed
>> > props, leaning, etc
>> > Everything you ever want to know about operating a high performance
>> > aircraft engine is in those articles.
>>
>>
>> Great link!
>>
>> I started reading this
>> article, http://www.avweb.com/news/columns/186619-1.html, and have a
>> question. In the Runup section, when he starts to test for proper mag
>> operation, somethings seems odd there. Can someone help explain that? He
>> says, "Are the mags working? The leaner the mixture, the more mag drop
>> you'll see on one mag, and that's normal." He then goes on to say, "The
>> EGTs should rise on the first single-mag operation, stay there for the
>> second, then drop again on the return to BOTH. That rise is proof-positive
>> the entire ignition system is working, and working well, and the leaner
>> the mixture, the more diagnostic it is."
>>
>> Can someone help explain the supporting logic there? If both mags are
>> working properly and you switch to a single mag, why would the EGT go up?
>> After all, in theory, you're producing less spark and thusly, a slightly
>> less effecient ignition of the fuel/air. I would of thought that EGT
>> would stay the same or go down *just slightly* when running off of one
>> mag. Likewise, if one mag is not working, I would fully expect to see a
>> big EGT drop for the given problematic mag, which he does agree with.
>> But, he further asserts that, "If any of them fail to rise or even drop
>> during single-mag operation, there is a problem with that plug, the wire,
>> or the mag."
>>
>> So, why would running on one mag, versus two, always cause higher EGTs?
>> And why would no rise in EGT indicate a bad mag, wire or plug?
>>
>> Anyone?
>>
>>
>> P.S. I cross posted because this seems like good student pilot material
>> too.
> The key is that with two plugs, the combustion _in the cylinder_ is more
> complete, earlier. When one mag cuts, the fuel air mixture still fully
> burns, but the burn is continued slightly latter (where it does less work on
> the piston). This results in the gas coming out of the exhaust being a
> little hotter (in some cases, it may even be still burning).
>
> Best Wishes

Makes perfect sense! Thanks!

Dudley Henriques

June 24th 04, 05:08 PM

I don't wish to sound like a smartass here, but what's your problem with
getting a full checkout in this airplane from a competent pilot current
in the aircraft?
It sounds like you might benefit from a bit of complex training here!!!
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt
"Greg Copeland" > wrote in message
...
> On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:
>
> > In article >, GE
> > > wrote:
> >
> >> I'm taking delivery today of my first aircraft and it had a
constant speed
> >> prop. I have only flown fixed props thus far. I want to have as
much
> >> understanding of the c-s prop as possible before I get with my
instructor. I
> >> understand the basic difference in what the controls do, but I
don't really
> >> have a good understanding of the hows and whys of flying with them.
Any
> >> general information, explanations, and tips would be greatly
appreciated.
> >
> > Go to www.avweb.com
> > on the left side of the screen, select COLUMNS
> > scroll down to find THE PELICAN"S PERCH
> > there are articles on fuel injection, manifold pressure, constant
speed
> > props, leaning, etc
> > Everything you ever want to know about operating a high performance
> > aircraft engine is in those articles.
>
>
> Great link!
>
> I started reading this
> article, http://www.avweb.com/news/columns/186619-1.html, and have a
> question. In the Runup section, when he starts to test for proper mag
> operation, somethings seems odd there. Can someone help explain that?
He
> says, "Are the mags working? The leaner the mixture, the more mag drop
> you'll see on one mag, and that's normal." He then goes on to say,
"The
> EGTs should rise on the first single-mag operation, stay there for the
> second, then drop again on the return to BOTH. That rise is
proof-positive
> the entire ignition system is working, and working well, and the
leaner
> the mixture, the more diagnostic it is."
>
> Can someone help explain the supporting logic there? If both mags are
> working properly and you switch to a single mag, why would the EGT go
up?
> After all, in theory, you're producing less spark and thusly, a
slightly
> less effecient ignition of the fuel/air. I would of thought that EGT
> would stay the same or go down *just slightly* when running off of one
> mag. Likewise, if one mag is not working, I would fully expect to see
a
> big EGT drop for the given problematic mag, which he does agree with.
> But, he further asserts that, "If any of them fail to rise or even
drop
> during single-mag operation, there is a problem with that plug, the
wire,
> or the mag."
>
> So, why would running on one mag, versus two, always cause higher
EGTs?
> And why would no rise in EGT indicate a bad mag, wire or plug?
>
> Anyone?
>
>
> P.S. I cross posted because this seems like good student pilot
material
> too.
>
>

Dudley Henriques

June 24th 04, 05:14 PM

The initial poster asking these questions sounds like he might benefit
from a complex checkout, or at least a thorough checkout in this
airplane given by a competent pilot current in the aircraft!
:-)
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt
"Greg Copeland" > wrote in message
...
> On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:
>
> > In article >, GE
> > > wrote:
> >
> >> I'm taking delivery today of my first aircraft and it had a
constant speed
> >> prop. I have only flown fixed props thus far. I want to have as
much
> >> understanding of the c-s prop as possible before I get with my
instructor. I
> >> understand the basic difference in what the controls do, but I
don't really
> >> have a good understanding of the hows and whys of flying with them.
Any
> >> general information, explanations, and tips would be greatly
appreciated.
> >
> > Go to www.avweb.com
> > on the left side of the screen, select COLUMNS
> > scroll down to find THE PELICAN"S PERCH
> > there are articles on fuel injection, manifold pressure, constant
speed
> > props, leaning, etc
> > Everything you ever want to know about operating a high performance
> > aircraft engine is in those articles.
>
>
> Great link!
>
> I started reading this
> article, http://www.avweb.com/news/columns/186619-1.html, and have a
> question. In the Runup section, when he starts to test for proper mag
> operation, somethings seems odd there. Can someone help explain that?
He
> says, "Are the mags working? The leaner the mixture, the more mag drop
> you'll see on one mag, and that's normal." He then goes on to say,
"The
> EGTs should rise on the first single-mag operation, stay there for the
> second, then drop again on the return to BOTH. That rise is
proof-positive
> the entire ignition system is working, and working well, and the
leaner
> the mixture, the more diagnostic it is."
>
> Can someone help explain the supporting logic there? If both mags are
> working properly and you switch to a single mag, why would the EGT go
up?
> After all, in theory, you're producing less spark and thusly, a
slightly
> less effecient ignition of the fuel/air. I would of thought that EGT
> would stay the same or go down *just slightly* when running off of one
> mag. Likewise, if one mag is not working, I would fully expect to see
a
> big EGT drop for the given problematic mag, which he does agree with.
> But, he further asserts that, "If any of them fail to rise or even
drop
> during single-mag operation, there is a problem with that plug, the
wire,
> or the mag."
>
> So, why would running on one mag, versus two, always cause higher
EGTs?
> And why would no rise in EGT indicate a bad mag, wire or plug?
>
> Anyone?
>
>
> P.S. I cross posted because this seems like good student pilot
material
> too.
>
>

Tom Sixkiller

June 24th 04, 05:14 PM

"C J Campbell" > wrote in message
...
> I think Deakin is worth reading, but some of what he says should be taken
> with a grain of salt. His columns are mostly based on experiments with his
> own highly modified Bonanza, a few high performance radial engines, and
some
> theory. In fact, a careful reading of his columns will show no test data
for
> the most common engine and propeller combinations in use today.

You've not read hiscolumns about the test beds they've run at GAMI?

The reasons
> for this are fairly simple -- few airplanes have the instrumentation that
> Deakin needs to test his theories. This is why Deakin's theories for
running
> lean of peak remain a minority view. Granted, it is a very noisy minority,
> but remember that it is also a small minority. I think they have a point.
> They may even be right. But they don't have nearly the evidence that they
> think they have.

See above.

> Deakin's remarks are mostly pertinent to running TCM engines, which are
much
> different than engines from other manufacturers.

I bellieve they run Lycoming on the test bed as well, everything from
pipsqueaks to the big 540's.

>Not to put too fine a point
> on it, some TCM engines are the only ones I know of that so consistently
> develop cracks that the most part of an annual inspection basically
consists
> of measuring and cataloging the spread of these cracks. The engine used in
> the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for
example.
>
> Barring solid data to the contrary (and Deakin, remember, does not give
you
> solid data -- he only appears to do that), your airplane should be
operated
> in accordance with the manufacturer's recommendations. This will ensure
that
> you maintain your insurance coverage, if nothing else.

I think GAMI generated enough data on their stand to run a computer dry.

http://www.engineteststand.com/

EDR

June 24th 04, 05:19 PM

I also highly recommend John C Eckalbar's books

FLYING THE BEECH BONANZA

and

FLYING HIGH PERFORMANCE SINGLES AND TWINS

These books will describe the relationship between aircraft weight and
the various V-speeds you should know when you fly.

Greg Copeland

June 24th 04, 05:21 PM

On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:

> I don't wish to sound like a smartass here, but what's your problem with
> getting a full checkout in this airplane from a competent pilot current
> in the aircraft?
> It sounds like you might benefit from a bit of complex training here!!!
> Dudley Henriques

I wondered the same thing, but you're replying to the wrong person. I'm a
student and GE posted the original question.

Cheers!

Dudley Henriques

June 24th 04, 06:47 PM

I caught that right after I posted it :-) I had cleaned out OE last
night back to four days old and missed the re: pickup. Thought I had
deleted this but obviously it didn't work!
Anyway.....it looks to me like the IP needs a complete checkout in this
airplane before flying it. His questions just seem way out of line for
someone taking delivery of an airplane they are rated and competent to
fly!
Sorry about the mispost :-)
DH
"Greg Copeland" > wrote in message
...
> On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:
>
> > I don't wish to sound like a smartass here, but what's your problem
with
> > getting a full checkout in this airplane from a competent pilot
current
> > in the aircraft?
> > It sounds like you might benefit from a bit of complex training
here!!!
> > Dudley Henriques
>
>
> I wondered the same thing, but you're replying to the wrong person.
I'm a
> student and GE posted the original question.
>
> Cheers!
>
>

Greg Copeland

June 24th 04, 07:39 PM

On Thu, 24 Jun 2004 09:14:59 -0700, Tom Sixkiller wrote:

>
> "C J Campbell" > wrote in message
> ...
>> I think Deakin is worth reading, but some of what he says should be taken
>> with a grain of salt. His columns are mostly based on experiments with his
>> own highly modified Bonanza, a few high performance radial engines, and
> some
>> theory. In fact, a careful reading of his columns will show no test data
> for
>> the most common engine and propeller combinations in use today.
>
> You've not read hiscolumns about the test beds they've run at GAMI?
>
>
> The reasons
>> for this are fairly simple -- few airplanes have the instrumentation that
>> Deakin needs to test his theories. This is why Deakin's theories for
> running
>> lean of peak remain a minority view. Granted, it is a very noisy minority,
>> but remember that it is also a small minority. I think they have a point.
>> They may even be right. But they don't have nearly the evidence that they
>> think they have.
>
> See above.
>
>> Deakin's remarks are mostly pertinent to running TCM engines, which are
> much
>> different than engines from other manufacturers.
>
> I bellieve they run Lycoming on the test bed as well, everything from
> pipsqueaks to the big 540's.
>
>>Not to put too fine a point
>> on it, some TCM engines are the only ones I know of that so consistently
>> develop cracks that the most part of an annual inspection basically
> consists
>> of measuring and cataloging the spread of these cracks. The engine used in
>> the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for
> example.
>>
>> Barring solid data to the contrary (and Deakin, remember, does not give
> you
>> solid data -- he only appears to do that), your airplane should be
> operated
>> in accordance with the manufacturer's recommendations. This will ensure
> that
>> you maintain your insurance coverage, if nothing else.
>
> I think GAMI generated enough data on their stand to run a computer dry.
>
> http://www.engineteststand.com/

Is the data offered in the articles you refer to or is it available on
the web site? It does not appear to be jumping out at me. I see a couple
of pictures of some graphs, a webring link, and email address, and a link
to gami.com. What am I missing?

Thanks,

Greg

[email protected]

June 24th 04, 08:38 PM

On Thu, 24 Jun 2004 08:55:30 -0700, "C J Campbell"
> wrote:

>I think Deakin is worth reading, but some of what he says should be taken
>with a grain of salt. His columns are mostly based on experiments with his
>own highly modified Bonanza, a few high performance radial engines, and some
>theory. In fact, a careful reading of his columns will show no test data for
>the most common engine and propeller combinations in use today. The reasons
>for this are fairly simple -- few airplanes have the instrumentation that
>Deakin needs to test his theories. This is why Deakin's theories for running
>lean of peak remain a minority view. Granted, it is a very noisy minority,
>but remember that it is also a small minority. I think they have a point.
>They may even be right. But they don't have nearly the evidence that they
>think they have.

Deakin's Bonanza is highly modified? I thought it had an ordinary
Continental TIO-550. Or is that engine considered highly modified?

Far as I know, from what I've read, the only extra instrument he has
on his instrument panel is the JPI EGT analyzer. He has said
repeatedly that in order to take advantage of running the engine lean
of peak, you really have to have a multi cylinder EGT guage, otherwise
you do not know if you are truly running all the cylinders lean of
peak. One or two may still be on the rich side or at peak which would
cause them to run a lot hotter than the lean ones.

>Deakin's remarks are mostly pertinent to running TCM engines, which are much
>different than engines from other manufacturers. Not to put too fine a point
>on it, some TCM engines are the only ones I know of that so consistently
>develop cracks that the most part of an annual inspection basically consists
>of measuring and cataloging the spread of these cracks. The engine used in
>the early 70's Cessna T206 rarely made it to its 1400 hour TBO, for example.
>
>Barring solid data to the contrary (and Deakin, remember, does not give you
>solid data -- he only appears to do that), your airplane should be operated
>in accordance with the manufacturer's recommendations. This will ensure that
>you maintain your insurance coverage, if nothing else.

I guess I'll have to ask why you think Deakin does not give solid
evidence for his recommendations. The GAMI folks (who's testing he
repeatedly cites) have been testing different types of engines for
years, and developed their precision injectors and proved them with
more testing before marketing them.

In addition, running engines lean of peak isn't new. When radial
engines were what powered most commercial aircraft, cruising them lean
of peak is what just about every pilot was trained to do. My father,
who flew PB4Y-1's and -2's and P2V Neptunes used to tell me about
flying them and how he set up for cruise and he mentioned the leaning
process. Ernest Gann talked about it. There were even percentage of
horsepower instruments in the big engined airliners that pilots were
required to adjust the engines to using the lean of peak setting. It
was the only way to get maximum range out of the airplane, at
reasonable speed.

Charles A. Lindbergh rather famously demonstrated to pilots in the
South Pacific during WWII how to greatly extend their range using lean
of peak operation. The technique worked for the F4U Corsair, the P-47
Thunderbolt, and most famously, the P-38 Lightning. The Lightning's
range was extended to such a degree that it permitted the large twin
engined fighter to accompany a bombing raid on a northern New Guinea
Japanese airbase, which had previously been out of range for fighters.
The Japanese were totally unprepared for the attack as they had
believed no bombing force would dare attack without fighter escort,
and they believed no American fighter had the range to make the trip
from Port Moresby. The attack is sometimes cited as perhaps the single
most effective raid of it's type in the Pacific War. How did
Lindbergh learn about lean of peak operation? I have no idea when he
first learned it or who taught him, but he knew about it when he made
his sort of well known solo trip across the Atlantic Ocean. He leaned
the engine visually, by leaning out the window and watching the
exhaust flame change color as he leaned the engine.

Deakin, as he stated several times in several different articles,
isn't introducing something new. He's re-intruducing a technique that
is old and well proven. It just did not work well with horizontally
opposed aircraft engines until now. It worked very well for radials
because the big ones all had impellers and equal length intake
manifold runners. The impellers distributed exactly the same fuel/air
mixture to each and every cylinder, every time it was ready to fire.
Horizontally opposed engines don't have the benefit of equal fuel/air
mixture being distributed to each cylinder. The GAMI people fix this
by taking your EGT readings which you give them when you install a
multi cylinder EGT guage and record the temperatures for each
cylinder. Then they send you a set of injectors calibrated for each
specific cylinder. If you install them properly (in the correct
cylinders, which is very important), the rich cylinders will be leaned
and the lean cylinders richened. The cylinder to cylinder
distribution now becomes equal enough that leaning should not produce
any rough engine operation. Some people had to return an injector to
be recalibrated, sometimes several times, but eventually the EGT's
reach relative uniformity.

If you can run the engine lean of peak without engine roughness, which
creates less heat in the engine, why would you not want to do that?
Less heat, less fuel burned, nearly the same speed at cruise (a little
less), what's wrong with this picture, anything? Can anyone explain
how this could possibly hurt the engine? It can't burn valves because
they are running cooler than they would if the mixture were set to
rich of peak operation. You can't cause detonation because that's a
result of heat and high power settings. The lean of peak setting is
normally used at or above 7,000 to 8,000 feet where no normally
aspirated engine is producing more than 60 or 65% power. With that
percentage of power, it's impossible to cause detonation. Even
Lycoming agrees with this.

Unless you really need to get somewhere at maximum possible speed, in
which case you would run the engine for best power which is a setting
on the rich side of peak, I don't understand why everyone would not
want to set for lean of peak cruise, when possible, if they have the
right instrumentation and the engine tolerates it.

It's possible that the POH's specify rich of peak operation because
that produces the highest cruise speeds, which is often what sells the
airplane.

Corky Scott

Richard Russell

June 24th 04, 08:41 PM

On Thu, 24 Jun 2004 17:47:41 GMT, "Dudley Henriques"
> wrote:

>I caught that right after I posted it :-) I had cleaned out OE last
>night back to four days old and missed the re: pickup. Thought I had
>deleted this but obviously it didn't work!
>Anyway.....it looks to me like the IP needs a complete checkout in this
>airplane before flying it. His questions just seem way out of line for
>someone taking delivery of an airplane they are rated and competent to
>fly!
>Sorry about the mispost :-)
>DH
>"Greg Copeland" > wrote in message
...
>> On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:
>>
>> > I don't wish to sound like a smartass here, but what's your problem
>with
>> > getting a full checkout in this airplane from a competent pilot
>current
>> > in the aircraft?
>> > It sounds like you might benefit from a bit of complex training
>here!!!
>> > Dudley Henriques
>>
>>
>> I wondered the same thing, but you're replying to the wrong person.
>I'm a
>> student and GE posted the original question.
>>
>> Cheers!
>>
>>
>
I applaud the original poster. He said, " I have only flown fixed
props thus far. I want to have as much
understanding of the c-s prop as possible before I get with my
instructor." He's trying to learn a little something in advance so he
doesn't start completely cold with the instructor. He is seeking
complex training and proactively preparing in advance for that
training.
Rich Russell

Andrew Gideon

June 24th 04, 09:08 PM

Dudley Henriques wrote:

> I caught that right after I posted it :-) I had cleaned out OE last
> night back to four days old and missed the re: pickup. Thought I had
> deleted this but obviously it didn't work!
> Anyway.....it looks to me like the IP needs a complete checkout in this
> airplane before flying it. His questions just seem way out of line for
> someone taking delivery of an airplane they are rated and competent to
> fly!
> Sorry about the mispost :-)
>

FWIW, I just (today!) completed complex and high performance checkouts.
Before I started the actual work, though, I read a fair bit on both the
specific aircraft and constant-speed prop use in general.

[I even posted some questions here, I believe.]

Reading ahead is never a bad idea, in my experience (granted: I don't read
many mysteries {8^).

- Andrew

Dave S

June 24th 04, 09:10 PM

Greg Copeland wrote:

> On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:
>
>
>>In article >, GE
> wrote:
>>
>>
>>>I'm taking delivery today of my first aircraft and it had a constant speed
>>>prop. I have only flown fixed props thus far. I want to have as much
>>>understanding of the c-s prop as possible before I get with my instructor. I
>>>understand the basic difference in what the controls do, but I don't really
>>>have a good understanding of the hows and whys of flying with them. Any
>>>general information, explanations, and tips would be greatly appreciated.
>>
>>Go to www.avweb.com
>>on the left side of the screen, select COLUMNS
>>scroll down to find THE PELICAN"S PERCH
>>there are articles on fuel injection, manifold pressure, constant speed
>>props, leaning, etc
>>Everything you ever want to know about operating a high performance
>>aircraft engine is in those articles.
>
>
>
> Great link!
>
> I started reading this
> article, http://www.avweb.com/news/columns/186619-1.html, and have a
> question. In the Runup section, when he starts to test for proper mag
> operation, somethings seems odd there. Can someone help explain that? He
> says, "Are the mags working? The leaner the mixture, the more mag drop
> you'll see on one mag, and that's normal." He then goes on to say, "The
> EGTs should rise on the first single-mag operation, stay there for the
> second, then drop again on the return to BOTH. That rise is proof-positive
> the entire ignition system is working, and working well, and the leaner
> the mixture, the more diagnostic it is."
>
> Can someone help explain the supporting logic there? If both mags are
> working properly and you switch to a single mag, why would the EGT go up?
> After all, in theory, you're producing less spark and thusly, a slightly
> less effecient ignition of the fuel/air. I would of thought that EGT
> would stay the same or go down *just slightly* when running off of one
> mag. Likewise, if one mag is not working, I would fully expect to see a
> big EGT drop for the given problematic mag, which he does agree with.
> But, he further asserts that, "If any of them fail to rise or even drop
> during single-mag operation, there is a problem with that plug, the wire,
> or the mag."
>
> So, why would running on one mag, versus two, always cause higher EGTs?
> And why would no rise in EGT indicate a bad mag, wire or plug?

Running on one mag means the fuel air mixture burns slower... so when
the exhaust valve opens, its still burning and the flame front travels
out the valve (or so ive been told).

If you get NO change with a mag check, then the burning characteristics
arent changing, that means the mag is not dropping offline.. which means
its not groundiing out.

I seem to remember this being explained in Deakin's articles but its
been a while since I've read them.

Dave

Dave S

June 24th 04, 09:16 PM

> It's possible that the POH's specify rich of peak operation because
> that produces the highest cruise speeds, which is often what sells the
> airplane.
>
> Corky Scott
>
>

The POH (provided by the airframe manufacturer) is not the same as an
operating manual provided by the engine manufacturer.

Dave

Dudley Henriques

June 24th 04, 09:18 PM

"Richard Russell" > wrote in message
...
> On Thu, 24 Jun 2004 17:47:41 GMT, "Dudley Henriques"
> > wrote:
>
> >I caught that right after I posted it :-) I had cleaned out OE last
> >night back to four days old and missed the re: pickup. Thought I had
> >deleted this but obviously it didn't work!
> >Anyway.....it looks to me like the IP needs a complete checkout in
this
> >airplane before flying it. His questions just seem way out of line
for
> >someone taking delivery of an airplane they are rated and competent
to
> >fly!
> >Sorry about the mispost :-)
> >DH
> >"Greg Copeland" > wrote in message
> ...
> >> On Thu, 24 Jun 2004 16:08:47 +0000, Dudley Henriques wrote:
> >>
> >> > I don't wish to sound like a smartass here, but what's your
problem
> >with
> >> > getting a full checkout in this airplane from a competent pilot
> >current
> >> > in the aircraft?
> >> > It sounds like you might benefit from a bit of complex training
> >here!!!
> >> > Dudley Henriques
> >>
> >>
> >> I wondered the same thing, but you're replying to the wrong person.
> >I'm a
> >> student and GE posted the original question.
> >>
> >> Cheers!
> >>
> >>
> >
> I applaud the original poster. He said, " I have only flown fixed
> props thus far. I want to have as much
> understanding of the c-s prop as possible before I get with my
> instructor." He's trying to learn a little something in advance so he
> doesn't start completely cold with the instructor. He is seeking
> complex training and proactively preparing in advance for that
> training.
> Rich Russell

You hope!!!

Could be, and most likely it's an ok scenario, but the correct answer I
believe is still to tell him to get the checkout; at least tell him this
along with supplying the data requested.
This is one of the drawbacks of aviation Usenet. You never know if
someone is taking a "shortcut" or seeking a head start going in the
right direction. You are probably right, but I notice that no one
answering this poster suggested that he get the checkout along with
supplying the data requested. :-)

Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt

PaulH

June 24th 04, 09:27 PM

One other factor to remember is that if you change to high RPM on
final and the engine is idling, you will increase the drag and steepen
your glide path, especially if the prop is 3-blade. That isn't
necessarily something you want to happen on final approach.

Andrew Gideon

June 24th 04, 09:38 PM

Dudley Henriques wrote:

> You hope!!!

Granted, he could be lying to us. But he did write "get with my
instructor". Admittedly, this is imprecise, but I took it to mean "...for
a checkout".

- Andrew

CVBreard

June 24th 04, 09:45 PM

>The key is that with two plugs, the combustion _in the cylinder_ is more
>complete, earlier. When one mag cuts, the fuel air mixture still fully
>burns, but the burn is continued slightly latter (where it does less work on

I can confirm that an engine running on one mag will show a higher EGT than on
both mags.

I went through the preflight, run-up, took off and during full-power climbout,
I noticed a significantly higher EGT than I was used to.

Startled me until I discovered that in the pre-takeoff mag check I had left the
mag switch on only one mag - I took off and was climbing on a single mag. Duh!

Switching to both mags brought the EGT back down to normal.

Bob Martin

June 25th 04, 01:07 AM

"PaulH" > wrote in message
om...
> One other factor to remember is that if you change to high RPM on
> final and the engine is idling, you will increase the drag and steepen
> your glide path, especially if the prop is 3-blade. That isn't
> necessarily something you want to happen on final approach.

Well, by the time you pull the power off enough to slow down for approach,
wouldn't the prop go to full fine pitch anyways (to try and maintain the set
RPM) and then drop farther? At that point you could push the prop control
all the way in without affecting the current RPM... at least, that's how it
works in the RV.

Dudley Henriques

June 25th 04, 01:40 AM

"Andrew Gideon" > wrote in message
online.com...
> Dudley Henriques wrote:
>
> > I caught that right after I posted it :-) I had cleaned out OE last
> > night back to four days old and missed the re: pickup. Thought I had
> > deleted this but obviously it didn't work!
> > Anyway.....it looks to me like the IP needs a complete checkout in
this
> > airplane before flying it. His questions just seem way out of line
for
> > someone taking delivery of an airplane they are rated and competent
to
> > fly!
> > Sorry about the mispost :-)
> >
>
> FWIW, I just (today!) completed complex and high performance
checkouts.
> Before I started the actual work, though, I read a fair bit on both
the
> specific aircraft and constant-speed prop use in general.
>
> [I even posted some questions here, I believe.]
>
> Reading ahead is never a bad idea, in my experience (granted: I don't
read
> many mysteries {8^).
>
> - Andrew

Nobody doubts that reading and studying ahead is the right way to go,
and I for one would of course encourage that. I also would encourage
pilots answering requests for this type of information to include as an
integral part of their answering post, the importance of getting this
checkout. I assume that since the poster specified he was preparing for
a proper checkout, this was why pilots answering didn't elaborate on it.
Dealing in flight safety and instruction all my life points any answer I
might give to this type of post toward reminding someone that the REAL
answers being sought will be found there, and not necessarily in the
prep work, which as we both agree, is fine and to be encouraged.
It's a matter of personal emphasis. Mine is ALWAYS on the proper
checkout as supplying the answers needed and NOT the prep work!
Just my style I guess :-)
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt

Dudley Henriques

June 25th 04, 01:43 AM

"Andrew Gideon" > wrote in message
online.com...
> Dudley Henriques wrote:
>
> > You hope!!!
>
> Granted, he could be lying to us. But he did write "get with my
> instructor". Admittedly, this is imprecise, but I took it to mean
"...for
> a checkout".
>
> - Andrew

So did I. I just believe that as important as any pre check flight prep
might be, the actual check flight and checkout procedure is far more
important to emphasize in the answer, as it relates to a specific
aircraft!
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt

C J Campbell

June 25th 04, 06:15 AM

"Tom Sixkiller" > wrote in message
...
>
> "C J Campbell" > wrote in message
> ...
> > I think Deakin is worth reading, but some of what he says should be
taken
> > with a grain of salt. His columns are mostly based on experiments with
his
> > own highly modified Bonanza, a few high performance radial engines, and
> some
> > theory. In fact, a careful reading of his columns will show no test data
> for
> > the most common engine and propeller combinations in use today.
>
> You've not read hiscolumns about the test beds they've run at GAMI?

I merely point out that his theories are controversial -- they are hardly
universally accepted, as even this thread amply demonstrates. As I said, I
think he has a point, but I have to consider that the engine manufacturers
and aircraft manufacturers might know at least as much about their products
as GAMI does.

Thomas Borchert

June 25th 04, 09:35 AM

C,

> If you are renting an airplane, though, run it the way the owner/operator
> wants it treated, which is invariably in accordance with the manufacturer's
> operating instructions.
>

I don't know. If there's a better way, why not embrace it. Most rentals I
know can't run LOP anyway, so the point is kind of moot.

--
Thomas Borchert (EDDH)

Thomas Borchert

June 25th 04, 09:35 AM

Greg,

> It bothered me how
> lean he was suggesting the engine should be run.
>

I am really interested: What exactly bothered you? What points in his
line of reasoning could you not follow? What part of his data did you
find lacking?

--
Thomas Borchert (EDDH)

Thomas Borchert

June 25th 04, 09:35 AM

Greg,

All the explanations you got are good. Now for the carb heat check.
What happens to the EGTs?

FWIW, a while ago I had a too high RPM drop on the mag check with our
Lyc O-360. A look at the engine monitor showed one cylinder's EGT going
very high. This points strongly to one plug being fouled. A little time
of running the engine at high rpm and very lean on the ground cleared
the problem, which could also clearly be seen on the engine monitor.
These things are worth their weight in gold, even on the simpler
engines.

--
Thomas Borchert (EDDH)

Thomas Borchert

June 25th 04, 09:35 AM

C,

> In fact, a careful reading of his columns will show no test data for
> the most common engine and propeller combinations in use today.
>

Well, my careful reading shows the opposite.

--
Thomas Borchert (EDDH)

June 25th 04, 01:45 PM

Thanks for your reply, as well as the debate on my actual intentions. "Get
with my instructor" was implying that I will be getting the proper training
in this aircraft from a qualified CFI. I simply wanted to increase my
knowledge prior to that instruction.

"Dudley Henriques" > wrote in message
ink.net...
> I don't wish to sound like a smartass here, but what's your problem with
> getting a full checkout in this airplane from a competent pilot current
> in the aircraft?
> It sounds like you might benefit from a bit of complex training here!!!
> Dudley Henriques
> International Fighter Pilots Fellowship
> Commercial Pilot/ CFI Retired
> For personal email, please replace
> the z's with e's.
> dhenriquesATzarthlinkDOTnzt
> "Greg Copeland" > wrote in message
> ...
> > On Thu, 24 Jun 2004 12:30:03 +0000, EDR wrote:
> >
> > > In article >, GE
> > > > wrote:
> > >
> > >> I'm taking delivery today of my first aircraft and it had a
> constant speed
> > >> prop. I have only flown fixed props thus far. I want to have as
> much
> > >> understanding of the c-s prop as possible before I get with my
> instructor. I
> > >> understand the basic difference in what the controls do, but I
> don't really
> > >> have a good understanding of the hows and whys of flying with them.
> Any
> > >> general information, explanations, and tips would be greatly
> appreciated.
> > >
> > > Go to www.avweb.com
> > > on the left side of the screen, select COLUMNS
> > > scroll down to find THE PELICAN"S PERCH
> > > there are articles on fuel injection, manifold pressure, constant
> speed
> > > props, leaning, etc
> > > Everything you ever want to know about operating a high performance
> > > aircraft engine is in those articles.
> >
> >
> > Great link!
> >
> > I started reading this
> > article, http://www.avweb.com/news/columns/186619-1.html, and have a
> > question. In the Runup section, when he starts to test for proper mag
> > operation, somethings seems odd there. Can someone help explain that?
> He
> > says, "Are the mags working? The leaner the mixture, the more mag drop
> > you'll see on one mag, and that's normal." He then goes on to say,
> "The
> > EGTs should rise on the first single-mag operation, stay there for the
> > second, then drop again on the return to BOTH. That rise is
> proof-positive
> > the entire ignition system is working, and working well, and the
> leaner
> > the mixture, the more diagnostic it is."
> >
> > Can someone help explain the supporting logic there? If both mags are
> > working properly and you switch to a single mag, why would the EGT go
> up?
> > After all, in theory, you're producing less spark and thusly, a
> slightly
> > less effecient ignition of the fuel/air. I would of thought that EGT
> > would stay the same or go down *just slightly* when running off of one
> > mag. Likewise, if one mag is not working, I would fully expect to see
> a
> > big EGT drop for the given problematic mag, which he does agree with.
> > But, he further asserts that, "If any of them fail to rise or even
> drop
> > during single-mag operation, there is a problem with that plug, the
> wire,
> > or the mag."
> >
> > So, why would running on one mag, versus two, always cause higher
> EGTs?
> > And why would no rise in EGT indicate a bad mag, wire or plug?
> >
> > Anyone?
> >
> >
> > P.S. I cross posted because this seems like good student pilot
> material
> > too.
> >
> >
>
>

Dudley Henriques

June 25th 04, 03:33 PM

"GE" > wrote in message
...
> Thanks for your reply, as well as the debate on my actual intentions.
"Get
> with my instructor" was implying that I will be getting the proper
training
> in this aircraft from a qualified CFI. I simply wanted to increase my
> knowledge prior to that instruction.

No problem, and I assumed you would be doing that. The reason I didn't
handle your post with the information you asked for is because there is
a difference between generics and specifics; and for what you will be
doing, specifics are called for. The checkout in a new complex is
aircraft specific and should be treated as such. Since you didn't state
what specific aircraft you were dealing with, I would refrain from
offering advice other than pointing you to the checkout procedure.
It's my practice that whenever a question like yours comes up without
stating what airplane the question is dealing with, I opt to steer the
poster to the checkout procedure rather than get into the specifics
requested. It's a safety issue with me......a personal preference so to
speak.
Best of luck with your checkout. I'm sure you'll do fine.
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt

Dave S

June 25th 04, 03:45 PM

God forbid someone is PROACTIVE enough to do the THEORY portion in
advance of the practical portion of instruction. I hope you wouldnt
consider me as trying to shortcut things because I had passed my private
written and was reading on instrument and commercial before I EVER took
my first lesson.

Dave

Dudley Henriques wrote:
> "Andrew Gideon" > wrote in message
> online.com...
>
>>Dudley Henriques wrote:
>>
>>
>>>You hope!!!
>>
>>Granted, he could be lying to us. But he did write "get with my
>>instructor". Admittedly, this is imprecise, but I took it to mean
>
> "...for
>
>>a checkout".
>>
>> - Andrew
>
>
> So did I. I just believe that as important as any pre check flight prep
> might be, the actual check flight and checkout procedure is far more
> important to emphasize in the answer, as it relates to a specific
> aircraft!
> Dudley Henriques
> International Fighter Pilots Fellowship
> Commercial Pilot/ CFI Retired
> For personal email, please replace
> the z's with e's.
> dhenriquesATzarthlinkDOTnzt
>
>

Tom Sixkiller

June 25th 04, 04:01 PM

"C J Campbell" > wrote in message
...
>
> "Tom Sixkiller" > wrote in message
> ...
> >
> > "C J Campbell" > wrote in message
> > ...
> > > I think Deakin is worth reading, but some of what he says should be
> taken
> > > with a grain of salt. His columns are mostly based on experiments with
> his
> > > own highly modified Bonanza, a few high performance radial engines,
and
> > some
> > > theory. In fact, a careful reading of his columns will show no test
data
> > for
> > > the most common engine and propeller combinations in use today.
> >
> > You've not read hiscolumns about the test beds they've run at GAMI?
>
> I merely point out that his theories are controversial -- they are hardly
> universally accepted, as even this thread amply demonstrates.

Ah...no, you said he doesn't support his conclusions. Charles "Cory" Scott
actually did a very elaborate reply that explains it better than I have the
patience for.

> As I said, I
> think he has a point, but I have to consider that the engine manufacturers
> and aircraft manufacturers might know at least as much about their
products
> as GAMI does.

You might want to look into that, because the test stand data shows they may
not know as much as they pretend. Sounds more to me like the manufacturers
are trying to cover their asses for poor quality and potential legal
liability.

Have you looked at the data that Cory and I pointed you to?

Tom Sixkiller

June 25th 04, 04:13 PM

Dudley Henriques

June 25th 04, 04:24 PM

"Dave S" > wrote in message
k.net...
> God forbid someone is PROACTIVE enough to do the THEORY portion in
> advance of the practical portion of instruction. I hope you wouldnt
> consider me as trying to shortcut things because I had passed my
private
> written and was reading on instrument and commercial before I EVER
took
> my first lesson.
>
> Dave

As usual with posts like yours; you have missed the point and read into
your comment something you wanted to see rather than what was actually
there.
No one is saying in any shape or form that proactive or theory work is a
negative. In fact, proactive and theory work are IMPERATIVE to success
in flying.
There's only one issue here, and that issue concerns the fact that the
initial poster didn't state the specific aircraft he was getting ready
to transition into. This should have been a red flag to pilots answering
his request for information.
The CORRECT response to his post in my opinion, since he didn't state
aircraft type, is either to simply point him to the checkout procedure,
or, if you want to address his questions specifically, at least find out
what he's flying before offering answers.
In my case, I don't offer generic answers when specific answers are
called for. It's that simple, and has absolutely nothing to do with
being opposed to theory and proactive work.

Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt

[email protected]

June 25th 04, 04:47 PM

On Thu, 24 Jun 2004 20:16:30 GMT, Dave S >
wrote:

>> It's possible that the POH's specify rich of peak operation because
>> that produces the highest cruise speeds, which is often what sells the
>> airplane.
>>
>> Corky Scott
>>
>>
>
>The POH (provided by the airframe manufacturer) is not the same as an
>operating manual provided by the engine manufacturer.

In regards whether to lean past peak or not and people following
proper procedures, here's what the Cessna Pilot Center Training manual
says:

"In order to lean, you pull back the mixture control knob until the
EGT guage reaches its highest temperature reading (called peak EGT)
and then starts to decrease. At this point enrich the mixture until
it's 50 degrees cooler than peak EGT. You can also lean by pulling
back the mixture control until the RPM just starts to decrease, then
continue leaning until it drops 25-50 rpm." Both instructions are
describing how to adjust the mixture to below peak EGT.

I've seen in Deakin's columns a response from Lycoming (response to
his mixture control columns) to the effect that "we would not
recommend lean of peak to our worst enemy". In light of the Cessna
Training Manual's instructions, I wonder if the two entities (Cessna
and Lycoming) should communicate a bit better?

Corky Scott

Greg Copeland

June 25th 04, 05:44 PM

On Fri, 25 Jun 2004 10:35:14 +0200, Thomas Borchert wrote:

> Greg,
>
>> It bothered me how
>> lean he was suggesting the engine should be run.
>>
>
> I am really interested: What exactly bothered you? What points in his
> line of reasoning could you not follow? What part of his data did you
> find lacking?

Well, keep in mind that it was the first article of his that I read. It
presumed that I had already been introduced to the LOP concept. I had
not. In fact, for some engines that I used (r/c nitro and car engines),
too lean is a great way to completely destroy an engine. Thusly, it did
bother me to see him talking about leaning an engine beyond where I would
normally expect it be richened back up.

Since that comment, I have continued to read many more of his articles. I
Think he makes many excellent points and has a powerful argument. Am I
completely sold on the notion? Nope. Am I interested enough to learn
more about it? Absoluetely. In fact, I pushed a pointer of his articles
to a pilot friend of mine (my father). It should make for some
interesting conversations. ;) I'll be interested to find out if he's
even heard of the concept before, as he's been flying before I was born.

Cheers!

Greg

[email protected]

June 25th 04, 07:09 PM

On Fri, 25 Jun 2004 11:44:30 -0500, Greg Copeland >
wrote:

>Well, keep in mind that it was the first article of his that I read. It
>presumed that I had already been introduced to the LOP concept. I had
>not. In fact, for some engines that I used (r/c nitro and car engines),
>too lean is a great way to completely destroy an engine.

But Greg, you just described a situation worlds apart from what Deakin
advocates. Running a race engine, any race engine, at full power and
too lean is not anywhere near the LOP description for aviation
engines. Yup, running an engine like that probably would blow it up.

Deakin is talking about cruising, with the engine producing no more
than 60% power. At 60% power virtually all experts agree that there
is no way to hurt the engine no matter where you decide to set the
mixture. Full rich, lean to the point where it's stumbling, it won't
matter, the engine can't hurt itself while making only 60% power.

For takeoff, his recommendation is to use FULL RICH. Not only full
rich, he recommends those who are flying behind the large 6 bangers
check out the mixture setup to make sure that it is reaching the
proper full fuel pressure. If it's set a little too low, something
below the specified maximum pressure, *THAT* situation is worrisome
and could cause engine problems. That's because the engine needs to
have the full rich mixture at takeoff power to stay cool. Having the
mixture on the rich side of ideal slows the burning down enough to
keep the Peak Pressure Point at around 16 degrees past top dead
center.

If the mixture isn't rich enough to achieve this, in other words if
it's a bit leaner, it may burn fast enough to cause the PPP to occur
with the piston closer to top dead center. The closer to top dead
center the PPP occurs, the higher the pressures and the more heat
produced, and THAT is why running rich keeps the engine cool.

This only happens, of course, because aircraft engines are stuck using
fixed timing. If they had automatically adjusted variable timing, the
mixture could be set for best power and left there (saving gas) with
no need to worry about whether the engine will overheat or not because
the timing would adjust to the proper 16 degrees ATDC regardless the
conditions or power setting.

And you thought "cooling the engine with fuel" literally meant that
the rich mixture hosed down the cylinder? <Big smile>

Corky Scott

Michael

June 25th 04, 10:24 PM

"C J Campbell" > wrote
> I merely point out that his theories are controversial -- they are hardly
> universally accepted, as even this thread amply demonstrates.

A thread on usenet demonstrates no such thing. Evolution is hardly
controversial within the scientific community, yet it is debated ad
nauseam on usenet. Deakin's theories (which are really not his at
all, and not really theories) are really no more controversial - in
fact, they formed the basis of normal operating practice for piston
fighter and airliners for as long as there were piston fighters and
airliners.

> As I said, I
> think he has a point, but I have to consider that the engine manufacturers
> and aircraft manufacturers might know at least as much about their products
> as GAMI does.

That was true once, but is true no longer. For all practical
purposes, there hasn't been any progress made in piston aircraft
engines for decades. Neither Lycoming nor Continental have a design
engineering staff anymore. Most of the knowledge has been lost.

It's actually fairly common for knowledge to be lost that way. Doing
development is fun; documenting it isn't. When the people who did the
development move on, a lot is lost. Corporate-mandated processes
generally don't help much - they just cause the brightest people to
move on sooner.

Michael

Greg Copeland

June 26th 04, 07:29 AM

On Fri, 25 Jun 2004 14:09:20 -0400, charles.k.scott wrote:

> On Fri, 25 Jun 2004 11:44:30 -0500, Greg Copeland >
> wrote:
>
>>Well, keep in mind that it was the first article of his that I read. It
>>presumed that I had already been introduced to the LOP concept. I had
>>not. In fact, for some engines that I used (r/c nitro and car engines),
>>too lean is a great way to completely destroy an engine.
>
> But Greg, you just described a situation worlds apart from what Deakin
> advocates.

I know that. But, when you're ignorant of the details of what he's
prescribing and know only the scary details of your own universe, it's a
natural reaction. I'm not saying it's justified. I'm just saying, that
was my reaction.

> Running a race engine, any race engine, at full power and
> too lean is not anywhere near the LOP description for aviation
> engines. Yup, running an engine like that probably would blow it up.

Yep. That's certainly a good point.

>
> For takeoff, his recommendation is to use FULL RICH. Not only full
> rich, he recommends those who are flying behind the large 6 bangers
> check out the mixture setup to make sure that it is reaching the
> proper full fuel pressure. If it's set a little too low, something
> below the specified maximum pressure, *THAT* situation is worrisome
> and could cause engine problems. That's because the engine needs to
> have the full rich mixture at takeoff power to stay cool. Having the
> mixture on the rich side of ideal slows the burning down enough to
> keep the Peak Pressure Point at around 16 degrees past top dead
> center.

I have read that article since my ignorant gut reaction was made known. ;)
I think he makes a lot of sense! I think he makes a powerful argument. I
think he goes to lengths to describe when, what, why, and how. That's all
excellent. But, if it's my $20k+ engine on the line, that's a long hard
thought before I'd commit to it. After all, he makes it perfectly clear
that you have to have an engine monitor, which makes it a
hole-in-your-wallet type of commitment for many. Not to mention,
irrational whispers in your head can sometimes just be a bitch to get
past, no matter what data is telling you. ;)

Needless to say, I'll certaily be looking more into it. It sounds very
interesting and it does seem to be well reseached, both presently and
historically. Just the same, I'd still like to be more educated on the
topic.

Cheers!

Greg

Thomas Borchert

June 26th 04, 08:58 AM

Greg,

> After all, he makes it perfectly clear
> that you have to have an engine monitor, which makes it a
> hole-in-your-wallet type of commitment for many.
>

One could (succesfully) make the argument that the information gleaned
from an engine monitor will save you more in money than it costs.

--
Thomas Borchert (EDDH)

Greg Copeland

June 26th 04, 04:53 PM

On Sat, 26 Jun 2004 09:58:44 +0200, Thomas Borchert wrote:

> Greg,
>
>> After all, he makes it perfectly clear
>> that you have to have an engine monitor, which makes it a
>> hole-in-your-wallet type of commitment for many.
>>
>
> One could (succesfully) make the argument that the information gleaned
> from an engine monitor will save you more in money than it costs.

This is true. I read one such example where he had an 18gph engine
running at 15gph. Anyone have any idea what can be done with some of the
smaller engines? Say, something in the 9-11gph range? If we assume the
same ratio of savings, that puts us at 7.5 - 9.2 gph, right? At a savings
(unsupported assumptions here) of 1.65gph, on average, at $2.40/g, that's
$3.96 saved per hour. At, say, 100hr/year, that's $396 saved per year.
If we assume the 700 series JP Instrument, installed, that's something
like $1700 - $2000 installed (right?). So, that means we can recoup our
investment in 4.3 to a little over 5 years. Ouch.

Granted, the more you fly and the bigger the fuel rate of your engine, the
quicker it's going to pay off, but I think it's hard to justify it across
the board on a economy savings basis.

If we run with the demoed 3gph savings, at $2.40g, that's $7.20/hr
savings. If we assume 200hr/yr, that's $1440 savings a year, which makes
the cheap JPI monitor paid for in about 1 1/4 years. And that is still
assuming that it's a four cylinder. Realistically, it's probably going to
be a 6-cylinder, which is going to raise the price again. So, again, even
with 200hr/yr, we're looking at something about two years for a return on
our investment.

So, it doesn't look like quite the sweatheart deal after all. Now, if
there are some supporting numbers which indicate a return on TBO, then we
might have something to sing about. ;)

Just some fun numbers for food for thought. :)

Cheers!

Greg

Richard Kaplan

June 27th 04, 02:47 AM

"Thomas Borchert" > wrote in message
...>

> One could (succesfully) make the argument that the information gleaned
> from an engine monitor will save you more in money than it costs.

It's not really an economic issue; an engine monitor can help diagnose
impending mechanical problems either on the ground or in the air before they
become more serious -- that's all the justification needed to install one.

---------------------
Richard Kaplan, CFII

www.flyimc.com

[email protected]

June 28th 04, 01:45 PM

On Sat, 26 Jun 2004 10:53:43 -0500, Greg Copeland >
wrote:

>So, again, even
>with 200hr/yr, we're looking at something about two years for a return on
>our investment.
>
>So, it doesn't look like quite the sweatheart deal after all. Now, if
>there are some supporting numbers which indicate a return on TBO, then we
>might have something to sing about. ;)
>
>Just some fun numbers for food for thought. :)
>
>Cheers!

Ok, it may take two years to get your investment back in money saved
from fuel not burned. Isn't that better than not getting any
realization of savings ever?

Also, Deakin doesn't say you must have the JPI instrument, there are
at least three other multicylinder EGT guages that show you what's
happening in each cylinder, including one that is NOT a digital LED
type. That one costs less than $1,000.

Corky Scott

Tom Sixkiller

June 28th 04, 04:19 PM

> wrote in message
...
> On Sat, 26 Jun 2004 10:53:43 -0500, Greg Copeland >
> wrote:
>
> >So, again, even
> >with 200hr/yr, we're looking at something about two years for a return on
> >our investment.
> >
> >So, it doesn't look like quite the sweatheart deal after all. Now, if
> >there are some supporting numbers which indicate a return on TBO, then we
> >might have something to sing about. ;)
> >
> >Just some fun numbers for food for thought. :)
> >
> >Cheers!
>
> Ok, it may take two years to get your investment back in money saved
> from fuel not burned.

And that's just fuel; it doesn't even take into account wear and tear due to
higher CHT temps.

> Isn't that better than not getting any
> realization of savings ever?

Let's see: About 40 cents a gallon time 15 gph = $6.00 and hour * 200 horus
a year = $1200 per year.

Figure in the amortized cost of a early TOH (two F33's I looked at had two
and three before they hit the 1700 TBO...one as early as 380 hours TTSN)
from running ROP (at least these two admitted such).

>
> Also, Deakin doesn't say you must have the JPI instrument, there are
> at least three other multicylinder EGT guages that show you what's
> happening in each cylinder, including one that is NOT a digital LED
> type. That one costs less than $1,000.

Quite. He merely says the JPI is _his_ favorite.

Greg Copeland

June 28th 04, 04:31 PM

On Mon, 28 Jun 2004 08:45:15 -0400, charles.k.scott wrote:

> On Sat, 26 Jun 2004 10:53:43 -0500, Greg Copeland >
> wrote:
>
>>So, again, even
>>with 200hr/yr, we're looking at something about two years for a return on
>>our investment.
>>
>>So, it doesn't look like quite the sweatheart deal after all. Now, if
>>there are some supporting numbers which indicate a return on TBO, then we
>>might have something to sing about. ;)
>>
>>Just some fun numbers for food for thought. :)
>>
>>Cheers!
>
> Ok, it may take two years to get your investment back in money saved
> from fuel not burned. Isn't that better than not getting any
> realization of savings ever?
>
> Also, Deakin doesn't say you must have the JPI instrument, there are
> at least three other multicylinder EGT guages that show you what's
> happening in each cylinder, including one that is NOT a digital LED
> type. That one costs less than $1,000.
>
> Corky Scott

Thanks. I've been meaning to look at the others. Have any urls to offer?

Greg

Greg Copeland

June 28th 04, 04:39 PM

On Mon, 28 Jun 2004 08:19:21 -0700, Tom Sixkiller wrote:

>> >So, it doesn't look like quite the sweatheart deal after all.
>> >>> >Now,
>>> >if
>> >there are some supporting numbers which indicate a return on TBO, then
>> >we might have something to sing about. ;)
>> >
>> >Just some fun numbers for food for thought. :)
>> >
>> Ok, it may take two years to get your investment back in money saved
>> from fuel not burned.
>
> And that's just fuel; it doesn't even take into account wear and tear
> due to higher CHT temps.

This is what I was hinting at. Does anyone know of any studies which can
associate an engine monitor with engine reliability, longevity, or reduced
TBO costs? Running engines past TBO?

I agree, common sense says, we'll see a happier engine resulting from
better managed temps, but is there anything that supports what a "happier
engine" translates into?

Greg

Michael Houghton

June 28th 04, 08:35 PM

Howdy!

In article >,
C J Campbell > wrote:
>
>"Tom Sixkiller" > wrote in message
...
>>
>> "C J Campbell" > wrote in message
>> ...
>> > I think Deakin is worth reading, but some of what he says should be
>taken
>> > with a grain of salt. His columns are mostly based on experiments with
>his
>> > own highly modified Bonanza, a few high performance radial engines, and
>> some
>> > theory. In fact, a careful reading of his columns will show no test data
>> for
>> > the most common engine and propeller combinations in use today.
>>
>> You've not read hiscolumns about the test beds they've run at GAMI?
>
>I merely point out that his theories are controversial -- they are hardly
>universally accepted, as even this thread amply demonstrates. As I said, I
>think he has a point, but I have to consider that the engine manufacturers
>and aircraft manufacturers might know at least as much about their products
>as GAMI does.
>
No. You do not "merely" point out... You do it in a manner that, intentional
or no, suggests that he is blowing smoke up your backside. You further
appear to completely disregard the supporting data and arguments, both from
GAMI testbeds and from historical operating practices for piston engined
aircraft. He does offer credible arguments that the engine manufacturers
offer recommendations contrary to good engineering and operating practices.

Let's be honest here.

yours,
Michael

--
Michael and MJ Houghton | Herveus d'Ormonde and Megan O'Donnelly
| White Wolf and the Phoenix
Bowie, MD, USA | Tablet and Inkle bands, and other stuff
| http://www.radix.net/~herveus/

C J Campbell

June 28th 04, 08:58 PM

"Michael Houghton" > wrote in message
...
> >
> No. You do not "merely" point out... You do it in a manner that,
intentional
> or no, suggests that he is blowing smoke up your backside. You further
> appear to completely disregard the supporting data and arguments, both
from
> GAMI testbeds and from historical operating practices for piston engined
> aircraft. He does offer credible arguments that the engine manufacturers
> offer recommendations contrary to good engineering and operating
practices.
>
> Let's be honest here.

All right, let's be honest. I am not disregarding the data that he as
presented in his articles. I will also not disregard the anecdotal evidence
that I have from several engine shops that engines consistently run LOP
generally do not make TBO, nor do they last as long as engines run according
to manufacturers' specifications. When Deakin comes up with hard evidence
that applies to anything other than GAMI's special setups then I will
welcome it. If there is anything that drives me up the wall, it is these
vague references to "historical operating practices." It is really just a
substitute for "bull****."

[email protected]

June 28th 04, 09:21 PM

On Mon, 28 Jun 2004 10:31:59 -0500, Greg Copeland >
wrote:

>
>Thanks. I've been meaning to look at the others. Have any urls to offer?
>
>Greg

I'll have to look em up. They are usually displayed in the Homebuilt
mags like Sport Aviation and Kitplanes. I should be getting the new
SA shortly.

Corky Scott

[email protected]

June 28th 04, 09:30 PM

On Mon, 28 Jun 2004 10:39:31 -0500, Greg Copeland >
wrote:

>I agree, common sense says, we'll see a happier engine resulting from
>better managed temps, but is there anything that supports what a "happier
>engine" translates into?
>
>Greg

This will be extremely difficult to quantify, because if you've read
all Deakin's columns, you will know that he feels that both Lycoming
and Continental have lost the ability to put together a long lasting
engine any longer. Also, there is a URL out there that describes the
problems the parallel head Lycoming 6 cylinder engine has in terms of
producing too much heat at the exhaust valve guide due to improper
original design back when they began installing hydraulic lifters.

This last piece of information is not from a Deaking column, it's from
two AP's who have done EXTENSIVE research on the problem of 6 cyl.
parallel valve Lycomings and why they can't seem to make TBO without
loosing compression because of excessive valve guide wear.

These guys traced it to the lack of oil flow to the valve guide, it's
that simple. Other engines that have MUCH more flow to the exhaust
valve guide do not suffer the same excessive valve guide wear.

See: http://egaa.home.mindspring.com/engine1.htm

What Deakin HAS said, and frequently, is that there are no engine
development engineers at Lycoming anymore. They've all retired.

Lycoming doesn't manufacture it's own parts anymore, they just
assemble what's sent them from outside sources.

But they still charge you plenty for them.

Corky Scott

Greg Copeland

June 29th 04, 12:55 AM

On Mon, 28 Jun 2004 16:30:08 -0400, charles.k.scott wrote:

> On Mon, 28 Jun 2004 10:39:31 -0500, Greg Copeland >
> wrote:
>
>>I agree, common sense says, we'll see a happier engine resulting from
>>better managed temps, but is there anything that supports what a "happier
>>engine" translates into?
>>
>>Greg
>
> What Deakin HAS said, and frequently, is that there are no engine
> development engineers at Lycoming anymore. They've all retired.
>
> Lycoming doesn't manufacture it's own parts anymore, they just
> assemble what's sent them from outside sources.
>

Okay. I've read enough to see Deakin really tear up two
engine manufacturers. Just the same, if people want to assert that using
an engine monitor is going to (greatly?) extend an engine's life, let's
see some data. If we accept Deakin's arguments at face value, that there
are fundimental design issues and no expertise to fix, then we should be
having a serious problem with any of the two manufacturer's engines
reaching TBO. Yet, many are reporting TBO and beyond. Likewise, if engine
monitors are really adding life back to an engine, surely someone (engine
monitor manufacturer?) can say, x% of engines which had monitors, on
average, lasted y% longer then those that did not. Until there is some
supporting evidence, I think Mr. Campbell (George?) makes a good stand on
his position about LOP, and by extention, engine monitors.

Do we have direct evidence to support that LOP adds life to an
engine? Do we have dirrect evidence to support that an engine monitor
will increase longevity? From what I'm hearing, in spite of Deakin's very
interesting reads, the answer is no.

Please, feel free to correct as needed!

Cheers!

Greg

Tom Sixkiller

June 29th 04, 03:31 AM

"C J Campbell" > wrote in message
...
>
> "Michael Houghton" > wrote in message
> ...
> > >
> > No. You do not "merely" point out... You do it in a manner that,
> intentional
> > or no, suggests that he is blowing smoke up your backside. You further
> > appear to completely disregard the supporting data and arguments, both
> from
> > GAMI testbeds and from historical operating practices for piston engined
> > aircraft. He does offer credible arguments that the engine manufacturers
> > offer recommendations contrary to good engineering and operating
> practices.
> >
> > Let's be honest here.
>
> All right, let's be honest. I am not disregarding the data that he as
> presented in his articles.

That's exactly what you're doing. You're also ingoring the parameters he
sets (that standard fatory injectors are so poorly done and out of spec that
LOP with standard injectors would cause one or more cylinders to run
excessivly hot (400 degrees plus).

> I will also not disregard the anecdotal evidence
> that I have from several engine shops that engines consistently run LOP
> generally do not make TBO, nor do they last as long as engines run
according
> to manufacturers' specifications.

Odd. Most of the anecdotal evidence shows that engines run according to
manufactureres specs (ie, ROP) DON'T make TBO. This is supported by the
DATA.

>When Deakin comes up with hard evidence
> that applies to anything other than GAMI's special setups then I will
> welcome it.

Well, the test stand has data for all sorts of setups and configurations and
you ignore THAT, so cut the crap.

>If there is anything that drives me up the wall, it is these
> vague references to "historical operating practices." It is really just a
> substitute for "bull****."

"Vague" reference?

Talk about bull****, and talk about shoving ones foot in mouth and playing
"pay no attention to that man behind the curtain...".

C J Campbell

June 29th 04, 06:53 AM

"Tom Sixkiller" > wrote in message
...
>
> "C J Campbell" > wrote in message
> ...
>
> >If there is anything that drives me up the wall, it is these
> > vague references to "historical operating practices." It is really just
a
> > substitute for "bull****."
>
> "Vague" reference?
>
> Talk about bull****, and talk about shoving ones foot in mouth and playing
> "pay no attention to that man behind the curtain...".

When someone tells me that 'historical operating practices' are different
from what has always been done, it automatically fails the baloney test.

[email protected]

June 29th 04, 12:45 PM

On Mon, 28 Jun 2004 16:21:11 -0400,
wrote:

>>
>>Thanks. I've been meaning to look at the others. Have any urls to offer?
>>
>>Greg
>
>I'll have to look em up. They are usually displayed in the Homebuilt
>mags like Sport Aviation and Kitplanes. I should be getting the new
>SA shortly.

When I arrived home last night, the July "Sport Aviation" was on the
table.

Electronics International is another alternative to JPI
<www.Buy-EI.com>

There is also Vision Microsystems Inc. which produces a multi cylinder
EGT as one part of a number of displays: <www.visionmicrosystems.com>

The company I mentioned that produces an analog EGT is KS Avionics:
<http://www.ksavionics.com/>

There are a few others offering EGT's within their glass panel along
with just about every instrument needed for flight, but those, like
the Microsystems version are a bit pricey. Or not, if you brave the
brave and use just that system and eliminate all analog instruments.
We're talking homebuilts here though, not sure how these will get into
certified airplanes.

Corky Scott

Thomas Borchert

June 29th 04, 02:59 PM

Greg,

GEM and EI are the main competitors to JPI, I would say. Google them.
As for newer aircraft, the tend to have these function integrated into
their Avidyne Entegra od Garmin G1000 systems. You'll see the
occasional Vision Microsystems, too.

--
Thomas Borchert (EDDH)

Greg Copeland

June 29th 04, 03:22 PM

On Tue, 29 Jun 2004 15:59:32 +0200, Thomas Borchert wrote:

> Greg,
>
> GEM and EI are the main competitors to JPI, I would say. Google them.
> As for newer aircraft, the tend to have these function integrated into
> their Avidyne Entegra od Garmin G1000 systems. You'll see the
> occasional Vision Microsystems, too.

Thanks. I'll check them out.

Greg

G.R. Patterson III

June 29th 04, 03:53 PM

Michael Houghton wrote:
>
> He does offer credible arguments that the engine manufacturers
> offer recommendations contrary to good engineering and operating practices.

AOPA also made that statement recently. In a recent "Airframe&Powerplant" article,
they stated "In fairness to both Lycoming and Teledyne Continental Motors, the
engine-operating instructions in POHs … appear to have been the result of marketing
decisions taking precedence over engineering recommendations."

I felt that it would have been more accurately phrased as "In fairness to both
Lycoming and Teledyne Continental Motors, their engineers are competent, but the
companies apparently lie through their teeth to get you to trash your engine and buy
a new one sooner."

George Patterson
None of us is as dumb as all of us.

C J Campbell

June 29th 04, 04:18 PM

"G.R. Patterson III" > wrote in message
...
>
>
> Michael Houghton wrote:
> >
> > He does offer credible arguments that the engine manufacturers
> > offer recommendations contrary to good engineering and operating
practices.
>
> AOPA also made that statement recently. In a recent "Airframe&Powerplant"
article,
> they stated "In fairness to both Lycoming and Teledyne Continental Motors,
the
> engine-operating instructions in POHs . appear to have been the result of
marketing
> decisions taking precedence over engineering recommendations."
>
> I felt that it would have been more accurately phrased as "In fairness to
both
> Lycoming and Teledyne Continental Motors, their engineers are competent,
but the
> companies apparently lie through their teeth to get you to trash your
engine and buy
> a new one sooner."

Ah, it is a giant conspiracy. I see it all now. Amazing that the tort boys
haven't latched onto this.

Now, just what engine-operating instructions was AOPA talking about?

Michael Houghton

June 29th 04, 04:58 PM

Howdy!

In article >,
C J Campbell > wrote:
>
>"Michael Houghton" > wrote in message
...
>> >
>> No. You do not "merely" point out... You do it in a manner that,
>intentional
>> or no, suggests that he is blowing smoke up your backside. You further
>> appear to completely disregard the supporting data and arguments, both
>from
>> GAMI testbeds and from historical operating practices for piston engined
>> aircraft. He does offer credible arguments that the engine manufacturers
>> offer recommendations contrary to good engineering and operating
>practices.
>>
>> Let's be honest here.
>
>All right, let's be honest. I am not disregarding the data that he as
>presented in his articles. I will also not disregard the anecdotal evidence
>that I have from several engine shops that engines consistently run LOP
>generally do not make TBO, nor do they last as long as engines run according

How do those engine shops discern that running LOP is the cause for failing
to make TBO? What is it about running LOP (assuming that the engine can be
run smoothly LOP) that is harder on engines?

>to manufacturers' specifications. When Deakin comes up with hard evidence
>that applies to anything other than GAMI's special setups then I will
>welcome it. If there is anything that drives me up the wall, it is these
>vague references to "historical operating practices." It is really just a
>substitute for "bull****."

I don't have fine details of how one operated piston engines in the 1940's,
1950's, and 1960's. However, Deakin refers (IIRC) to how one *had* to operate
R-3350s to get anything like acceptable range, and that was LOP. Right there
in the manuals the flight engineers were guided by. At least, that is my
understanding.

Further, note the references to how one extended the range of large american
fighters, both with round and straight engines, in WWII. LOP operations were
critical to that.

References to "historical operating practices" are no more bull**** than your
continuing dismissal of demonstrable facts such as those articulated by
John Deakin.

I call "bull****" on you.

Deakin cites test-stand data that is current and, so far as I can tell,
valid. He also is careful to note when you can and can not make effective
use of LOP operations, both by flight regime and by engine equippage.

You seem to place equal stock in anecdotes from engine shops that blame
early engine failure on LOP operations. What are those shops bona fides to
make that determination? Is it really LOP or is it attempting to run LOP
but not quite getting there, leading to running a cylinder or two at
the worst possible place (which, IIRC, is where some operating manuals
would have you run the engine).

yours,
Michael
>
>

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