Lycoming's views on best economy settings

In article ,
Mike Rhodes wrote:

As for Lycoming recommending against LOP, there was an article in
Flying magazine (p. 74-75, 7/02, inset article, J.Mac) , where there
was some sort of lead crystalline deposit (lead oxybromide) forming in
_turbo_ engines only in LOP operations.

I've snipped the rest since it is full of old wives tales. The
theory of lead oxybromide came from a poorly investigated accident
in Austrailia.

John Deakin analyzes the accident, and Flying's coverage of it.

Accident: http://www.avweb.com/news/columns/182152-1.html

Flying's coverage: http://www.avweb.com/news/columns/182153-1.html

Deakin also covers LOP in alot of his articles, specifically the
ones titled 'Where should I run my engine?' He goes into the
science of how an engine actually works, and examines how the
'your engine will burn up if you do that' OWTs relate to reality.

All of Deakin's articles: http://www.avweb.com/news/columns/182146-1.html

John
--
John Clear - http://www.panix.com/~jac

"John Clear" wrote in message
...

I've snipped the rest since it is full of old wives tales. The
theory of lead oxybromide came from a poorly investigated accident
in Austrailia.

John Deakin analyzes the accident, and Flying's coverage of it.

Accident: http://www.avweb.com/news/columns/182152-1.html

Flying's coverage: http://www.avweb.com/news/columns/182153-1.html

You missed the best bit, where the coroner slates the ATSB investigation.
:-)

http://www.airsafety.com.au/whyalla/default.htm

has the chronology.

Julian Scarfe

On 29 Jun 2004 22:13:49 -0700, (John Clear) wrote:

In article ,
Mike Rhodes wrote:

As for Lycoming recommending against LOP, there was an article in
Flying magazine (p. 74-75, 7/02, inset article, J.Mac) , where there
was some sort of lead crystalline deposit (lead oxybromide) forming in
_turbo_ engines only in LOP operations.

I've snipped the rest since it is full of old wives tales. The
theory of lead oxybromide came from a poorly investigated accident
in Austrailia.

John Deakin analyzes the accident, and Flying's coverage of it.

Accident: http://www.avweb.com/news/columns/182152-1.html

Flying's coverage: http://www.avweb.com/news/columns/182153-1.html

Deakin also covers LOP in alot of his articles, specifically the
ones titled 'Where should I run my engine?' He goes into the
science of how an engine actually works, and examines how the
'your engine will burn up if you do that' OWTs relate to reality.

All of Deakin's articles: http://www.avweb.com/news/columns/182146-1.html

John

So I can ignore all the hysterics and lean to roughness, then enrichen
it to smoothness. And we all should do so in any piston engine, as
long as the power is markedly below 75%.

Mike

In article ,
Mike Rhodes wrote:
Deakin also covers LOP in alot of his articles, specifically the
ones titled 'Where should I run my engine?' He goes into the
science of how an engine actually works, and examines how the
'your engine will burn up if you do that' OWTs relate to reality.

All of Deakin's articles: http://www.avweb.com/news/columns/182146-1.html

So I can ignore all the hysterics and lean to roughness, then enrichen
it to smoothness. And we all should do so in any piston engine, as
long as the power is markedly below 75%.

Without an engine analyzer, you have know way of knowing how bad
the fuel/air mixture is in each cylinder. Running at the standard
50F rich of peak EGT puts you right in the 'Red Zone'. Running
100-150F ROP is a better place to run the engine if you can't run
LOP smoothly. Most non-fuel injected engines have such large
differences in fuel/air mixture between cylinders that they can't
be run LOP smoothly.

At lower power settings, it doesn't matter much where you run your
engine since lower power means lower heat and pressure.

Deakin does a much better job of explaining all this.

John
--
John Clear - http://www.panix.com/~jac

"John Clear" wrote in message
...
In article ,
Mike Rhodes wrote:
Deakin also covers LOP in alot of his articles, specifically the
ones titled 'Where should I run my engine?' He goes into the
science of how an engine actually works, and examines how the
'your engine will burn up if you do that' OWTs relate to reality.

All of Deakin's articles:
http://www.avweb.com/news/columns/182146-1.html

So I can ignore all the hysterics and lean to roughness, then enrichen
it to smoothness. And we all should do so in any piston engine, as
long as the power is markedly below 75%.

Without an engine analyzer, you have know way of knowing how bad
the fuel/air mixture is in each cylinder. Running at the standard
50F rich of peak EGT puts you right in the 'Red Zone'. Running
100-150F ROP is a better place to run the engine if you can't run
LOP smoothly. Most non-fuel injected engines have such large
differences in fuel/air mixture between cylinders that they can't
be run LOP smoothly.

At lower power settings, it doesn't matter much where you run your
engine since lower power means lower heat and pressure.

Deakin does a much better job of explaining all this.


Save your breath.

Numerous people have pointed out the articles. Evidently Rhodes is unwilling
to read them or cannot comprehend them.

On Wed, 30 Jun 2004 13:16:14 -0500, Mike Rhodes
wrote:

So I can ignore all the hysterics and lean to roughness, then enrichen
it to smoothness. And we all should do so in any piston engine, as
long as the power is markedly below 75%.

Mike

What Deakin suggests is that you get yourself a multi cylinder EGT
guage that can tell you what the temperatures are for the EGT and CHT
for ALL the cylinders.

Without that instrument and even with a single point EGT guage, you
have no idea where the CHT's are when you lean by that method. He
frequently characterized the typical Lycoming/Continental engine as a
group of cylinders flying along loosely in formation because the
temperature readings from one cylinder to the other can vary so much
you'd think they were from some other engine.

Maybe you've leaned to a safe settng but maybe not. Deakin advocates
knowing for sure. Seems like good, albeit expensive advice.

Corky Scott

"Mike Rhodes" wrote in message
...
On 29 Jun 2004 22:13:49 -0700, (John Clear) wrote:

In article ,
Mike Rhodes wrote:

As for Lycoming recommending against LOP, there was an article in
Flying magazine (p. 74-75, 7/02, inset article, J.Mac) , where there
was some sort of lead crystalline deposit (lead oxybromide) forming in
_turbo_ engines only in LOP operations.

I've snipped the rest since it is full of old wives tales. The
theory of lead oxybromide came from a poorly investigated accident
in Austrailia.

John Deakin analyzes the accident, and Flying's coverage of it.

Accident: http://www.avweb.com/news/columns/182152-1.html

Flying's coverage: http://www.avweb.com/news/columns/182153-1.html

Deakin also covers LOP in alot of his articles, specifically the
ones titled 'Where should I run my engine?' He goes into the
science of how an engine actually works, and examines how the
'your engine will burn up if you do that' OWTs relate to reality.

All of Deakin's articles: http://www.avweb.com/news/columns/182146-1.html

John

So I can ignore all the hysterics and lean to roughness, then enrichen
it to smoothness. And we all should do so in any piston engine, as
long as the power is markedly below 75%.


No...you can read the articles and try to LEARN something instead of
shooting your mouth off with your foot still in it.

On Thu, 1 Jul 2004 10:45:43 -0700, "Tom Sixkiller"
wrote:

"Mike Rhodes" wrote in message
.. .

All of Deakin's articles: http://www.avweb.com/news/columns/182146-1.html

John

So I can ignore all the hysterics and lean to roughness, then enrichen
it to smoothness. And we all should do so in any piston engine, as
long as the power is markedly below 75%.


No...you can read the articles and try to LEARN something instead of
shooting your mouth off with your foot still in it.


I glanced at one page of Deakin and thought the writing entertaining,
& therefore also distracting. That was not intended as a critique of
his understanding, though there appears to be a bit of desparation in
that regard. Deakin's kind of wordy, especially if its expected to be
used as reference material -- like from this news group.

I think it unusual to be dissed for not reading something, and I got
that feeling even before the above. So I chose not to pour over the
material, which is not written as if it were intended to be used for
reference. If you have a specific page I'd be glad to check it out;
but not all of his articles. If I like that then I may read more, but
on my time.

Otherwise, quoting the header post by Mr. Scott, (and this is general
info as I know/knew it)...

Remember, when you are cruising at 60% power, you cannot hurt the
engine no matter where you set the mixture control. You can't burn
valves or cook the cylinderheads or cause detonation, it just isn't
producing enough power to do that.

Therefore I think I can assume (for I always have), that no 'red zone'
actually exists in cruise throttle, as was mentioned someplace else in
the thread.

My 2nd reply, which is stated on top of this post (leaning to
roughness), is therefore allowed, and without qualification, by the
'can't hurt engine at 60%'. The words "best economy" are in the title
of this thread.

Mr. Scott's polite reply (thank-you) to my lean-to-roughness said I
"may have leaned to a safe setting, maybe not." But this is in
conflict with his own statement above, for which he then gave no
explanation, except to suggest the engine analyzer. But if the engine
is below 75% power then what difference does it make what mixture is
in any particular cylinder? If I need economy I go to roughness. If
I need speed then I enrichen it to gain power. And I would expect
more wear-and-tear at the higher power of richer mixture settings --
_IF_ I get higher power at richer mixture and don't begin to waste
fuel. I can monitor my airspeed to see where an another optimum
mixture setting exists.

(Apologies for putting all my replies into this post, for my first,
semi-uneducated post. It was an honest question on my part.)

--Mike

In article , Mike Rhodes wrote:
things to tend to) invites catastrophic trouble in any engine. And
for the pilot to get in that habit in normally-aspirated engines can,
after the pilot upgrades, apparently inflict harm on turbo engines.
snip

I've never bought the argument of "don't get in the habit of this,
because if you move to X type of different aircraft, it's bad".
Operating one engine sub-optimally because it's not done in another type
seems a bit silly to me - surely pilots should fly each different type
appropriately, instead of by habit?

If someone tells me "don't operate your C140/Auster/Champ [...] like
this because if you move to a turbo Bonanza, doing that will be
harmful", I tend to ignore them and continue to operate each aircraft
appropriately.

--
Dylan Smith, Castletown, Isle of Man
Flying: http://www.dylansmith.net
Frontier Elite Universe: http://www.alioth.net
"Maintain thine airspeed, lest the ground come up and smite thee"

Mike,

there was an article in
Flying magazine (p. 74-75, 7/02, inset article, J.Mac) , where there
was some sort of lead crystalline deposit (lead oxybromide) forming in
_turbo_ engines only in LOP operations.

Complete, total poppycock, as many sources available on the web show.


Running lean, by a moment of carelessness (pilots have lots of
things to tend to) invites catastrophic trouble in any engine.

Yes? Says who?

--
Thomas Borchert (EDDH)