Today's Message Index:
----------------------
1. 06:14 PM - Lean of Peak and other heresies (LES KEARNEY)
2. 06:48 PM - Re: Lean of Peak and other heresies (Pascal)
3. 06:50 PM - Re: Lean of Peak and other heresies (Miller John)
4. 07:08 PM - Speaking of Mike Busch: Manifesto (Tim Olson)
5. 07:19 PM - Re: Lean of Peak and other heresies (Les Kearney)
6. 07:32 PM - Re: Lean of Peak and other heresies (Bob Turner)
7. 07:49 PM - Re: Lean of Peak and other heresies (Pascal)
8. 07:54 PM - Re: Lean of Peak and other heresies (Kelly McMullen)
9. 07:56 PM - Re: Re: Lean of Peak and other heresies (Kelly McMullen)
10. 08:22 PM - Re: Lean of Peak and other heresies (Les Kearney)
11. 08:48 PM - Re: Lean of Peak and other heresies (Kelly McMullen)
12. 08:48 PM - Re: Lean of Peak and other heresies (Jesse Saint)
13. 08:57 PM - Re: Lean of Peak and other heresies (Don McDonald)
14. 09:06 PM - Re: Lean of Peak and other heresies (Les Kearney)
15. 09:07 PM - Re: Lean of Peak and other heresies (Kelly McMullen)
16. 09:18 PM - Re: Lean of Peak and other heresies (Kelly McMullen)
17. 09:41 PM - Want to fly and own an RV-10 (Dave Bockelman)
Message 1
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| Subject: | Lean of Peak and other heresies |
Hi
At KOSH I received some very conflicted info on lean of peak ops with an IO540.
Continental (admittedly not a Lyc IO540), had a wonderful simulation / presentation
about how to safely run LOP. Their position was to stay under 65% power to
avoid the "red Box".
Lycoming seemed to think that LOP was was a high risk venture that most mere mortals
should avoid like the plague. They even has a 2000 monograph that had a
few veiled references to Gami.
Mike Busch was very much in support of LOP ops in either brand C or L engines.
His view was physics doesnt't change with the brand of engine.
So, given that we have now resolved how to properly prime lithium batteries, I
would be interested in hearing about first hand LOP experiences. Has anyone experienced
problems with LOP. Lycoming seems to think that LOP requires more attention
to detail than the average pilot can muster when things busy. They also
suggest that ROP at power settings that match LOP power yields similar albeit
somewhat higher fuel flows. Does actual experience bear this out?
Any comments?
Cheers
Les
Inquiring minds need to know!
Message 2
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| Subject: | Re: Lean of Peak and other heresies |
Plainly put the lycoming rep was uneducated on the Lycoming stance:
http://www.avweb.com/news/maint/182849-1.html?redirected=1
Lie #7:
Aggressive leaning results in burned valves and detonation.
Fear of the red knob is one of the most pernicious areas of
misinformation among general aviation pilots. Most pilots operate way
too rich most of the time, and do so because of the mistaken belief that
leaning will harm their engine. The result is usually trouble: fouled
spark plugs, accelerated exhaust valve guide wear, and stuck exhaust
valves.
Lycoming engine Lycoming has long authorized leaning to peak EGT at any
cruise setting up to 75% power. TCM authorizes leaning to peak EGT up to
65%, and its latest recommendations even endorse lean-of-peak operation
for many big-bore engines, provided the engines will run smoothly when
operated that lean.
Contrary to popular belief, aggressive leaning doesn't cause burned
valves. Most burned valves are the result of excessive valve guide wear
or valve stem contamination.
Aggressive leaning doesn't cause detonation, either. Most of our engines
are incapable of detonation at cruise power settings, provided that we
don't exceed CHT red-line or try to burn contaminated fuel. Furthermore,
recent tests on Lycoming engines by ASTM revealed this fascinating
result: detonation is most likely to occur at a mixture setting 11%
richer than stoichiometric (i.e., substantially richer than peak EGT).
Lean as aggressively as the book allows. For Lycomings, that means peak
EGT at all cruise power settings to 75%. For Continentals, lean to peak
EGT up to 65%, 50=C2=B0F rich of peak at 75%. For turbocharged engines,
also limit TIT to 1600=C2=B0F.
Lean during all ground operations except for engine start. It is
particularly important to lean for taxi and runup. Since EGT is usually
off-scale at idle power, the best method is to lean for peak RPM at
idle.
Read through Lycoming=99s Key Operations- found on the lycoming
site. Plenty about leaning at 75% and lower and even a chart that says
they do not recommend LOP, but on the same page has:
pg38
6. Leaning to best economy mixture.
a. Set manifold pressure and RPM for the desired cruise power setting
per the aircraft POH/AFM.
b. Lean slowly in small steps, while monitoring instrumentation, to peak
TIT or maximum allowable TIT, whichever occurs first
than on pg 39:
Once cruise power has been set, leaning to best economy should be
standard procedure as damage to the engine will not occur from leaning
at cruise power settings.
-----Original Message-----
From: LES KEARNEY
Sent: Monday, August 11, 2014 6:09 PM
Subject: RV10-List: Lean of Peak and other heresies
Hi
At KOSH I received some very conflicted info on lean of peak ops with an
IO540.
Continental (admittedly not a Lyc IO540), had a wonderful simulation /
presentation about how to safely run LOP. Their position was to stay
under 65% power to avoid the "red Box".
Lycoming seemed to think that LOP was was a high risk venture that most
mere mortals should avoid like the plague. They even has a 2000
monograph that had a few veiled references to Gami.
Mike Busch was very much in support of LOP ops in either brand C or L
engines. His view was physics doesnt't change with the brand of engine.
So, given that we have now resolved how to properly prime lithium
batteries, I would be interested in hearing about first hand LOP
experiences. Has anyone experienced problems with LOP. Lycoming seems to
think that LOP requires more attention to detail than the average pilot
can muster when things busy. They also suggest that ROP at power
settings that match LOP power yields similar albeit somewhat higher fuel
flows. Does actual experience bear this out?
Any comments?
Cheers
Les
Inquiring minds need to know!
Message 3
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| Subject: | Re: Lean of Peak and other heresies |
Les,
I've been using Mike Busch's techniques with my Lyc IO540 and they work just great.
My CHTs typically run 300 - 340 max or so at 65% and LOP, and are lower
when I run less than 65% power.
I make the "big pull" to lean it out thus not spending any time in the "Red Box".
Fuel flows for me are typically 11 - 11.5gph at 65% power and that gives me @150KTAS
in the 5 - 9k range.
Mike knows his stuff, and I just recently changed to a paid subscription on his
website after hearing him talk about his new analysis capability for detecting
early exhaust valve failures.
His website for uploading your data is an outstanding diagnostic tool, and beats
the propriety program I have been using for years.
grumpy
do not archive
On Aug 11, 2014, at 8:09 PM, LES KEARNEY <kearney@shaw.ca> wrote:
>
> Hi
>
> At KOSH I received some very conflicted info on lean of peak ops with an IO540.
>
> Continental (admittedly not a Lyc IO540), had a wonderful simulation / presentation
about how to safely run LOP. Their position was to stay under 65% power
to avoid the "red Box".
>
> Lycoming seemed to think that LOP was was a high risk venture that most mere
mortals should avoid like the plague. They even has a 2000 monograph that had
a few veiled references to Gami.
>
> Mike Busch was very much in support of LOP ops in either brand C or L engines.
His view was physics doesnt't change with the brand of engine.
>
> So, given that we have now resolved how to properly prime lithium batteries,
I would be interested in hearing about first hand LOP experiences. Has anyone
experienced problems with LOP. Lycoming seems to think that LOP requires more
attention to detail than the average pilot can muster when things busy. They also
suggest that ROP at power settings that match LOP power yields similar albeit
somewhat higher fuel flows. Does actual experience bear this out?
>
> Any comments?
>
> Cheers
>
> Les
> Inquiring minds need to know!
>
>
>
>
Message 4
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| Subject: | Speaking of Mike Busch: Manifesto |
I just today finished reading "Manifesto" by Mike Busch. I think he did a pretty
good job on this book but look forward to the rest in the series to get more
detail. I really think he's spot on with his views on maintenance based on
time in service. Anyway, I think it's a great boot and was quick and cheap to
get on Amazon, and I read it in an hour or two.
Tim
Message 5
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| Subject: | Re: Lean of Peak and other heresies |
Hi Pascal
Here is a link to the monograph I hot from Lycoming at KOSH.
http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
Cheers
Les
Sent from my iPhone
> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
>
> Plainly put the lycoming rep was uneducated on the Lycoming stance:
> http://www.avweb.com/news/maint/182849-1.html?redirected=1
> Lie #7:
> Aggressive leaning results in burned valves and detonation.
>
> Fear of the red knob is one of the most pernicious areas of misinformation
among general aviation pilots. Most pilots operate way too rich most of the
time, and do so because of the mistaken belief that leaning will harm their
engine. The result is usually trouble: fouled spark plugs, accelerated exha
ust valve guide wear, and stuck exhaust valves.
>
> Lycoming engine Lycoming has long authorized leaning to peak EGT at any c
ruise setting up to 75% power. TCM authorizes leaning to peak EGT up to 65%,
and its latest recommendations even endorse lean-of-peak operation for many
big-bore engines, provided the engines will run smoothly when operated that
lean.
>
> Contrary to popular belief, aggressive leaning doesn't cause burned valves
. Most burned valves are the result of excessive valve guide wear or valve s
tem contamination.
>
> Aggressive leaning doesn't cause detonation, either. Most of our engines a
re incapable of detonation at cruise power settings, provided that we don't
exceed CHT red-line or try to burn contaminated fuel. Furthermore, recent t
ests on Lycoming engines by ASTM revealed this fascinating result: detonatio
n is most likely to occur at a mixture setting 11% richer than stoichiometri
c (i.e., substantially richer than peak EGT).
>
> Lean as aggressively as the book allows. For Lycomings, that means peak EG
T at all cruise power settings to 75%. For Continentals, lean to peak EGT up
to 65%, 50=C2=B0F rich of peak at 75%. For turbocharged engines, also limit
TIT to 1600=C2=B0F.
>
> Lean during all ground operations except for engine start. It is particula
rly important to lean for taxi and runup. Since EGT is usually off-scale at i
dle power, the best method is to lean for peak RPM at idle.
>
> Read through Lycoming=99s Key Operations- found on the lycoming site
. Plenty about leaning at 75% and lower and even a chart that says they do n
ot recommend LOP, but on the same page has:
> pg38
> 6. Leaning to best economy mixture.
> a. Set manifold pressure and RPM for the desired cruise power setting per t
he aircraft POH/AFM.
> b. Lean slowly in small steps, while monitoring instrumentation, to peak T
IT or maximum allowable TIT, whichever occurs first
> <image[3].png>
>
> than on pg 39:
> Once cruise power has been set, leaning to best economy should be standard
procedure as damage to the engine will not occur from leaning at cruise pow
er settings.
>
>
> -----Original Message-----
> From: LES KEARNEY
> Sent: Monday, August 11, 2014 6:09 PM
> To: rv10-list@matronics.com
> Subject: RV10-List: Lean of Peak and other heresies
>
>
> Hi
>
> At KOSH I received some very conflicted info on lean of peak ops with an I
O540.
>
> Continental (admittedly not a Lyc IO540), had a wonderful simulation / pre
sentation about how to safely run LOP. Their position was to stay under 65% p
ower to avoid the "red Box".
>
> Lycoming seemed to think that LOP was was a high risk venture that most me
re mortals should avoid like the plague. They even has a 2000 monograph that
had a few veiled references to Gami.
>
> Mike Busch was very much in support of LOP ops in either brand C or L engi
nes. His view was physics doesnt't change with the brand of engine.
>
> So, given that we have now resolved how to properly prime lithium batterie
s, I would be interested in hearing about first hand LOP experiences. Has an
yone experienced problems with LOP. Lycoming seems to think that LOP require
s more attention to detail than the average pilot can muster when things bus
y. They also suggest that ROP at power settings that match LOP power yields s
imilar albeit somewhat higher fuel flows. Does actual experience bear this o
ut?
>
> Any comments?
>
> Cheers
>
> Les
> Inquiring minds need to know!
>
> ============
> RV10-List Email Forum -
> http://www.matronics.com/Navigator?RV10-List ==========
=== sp; - MATRONICS WEB FORUMS - ============
= sp; - List Contribution Web Site - sp; -Matt Dralle,
List Admin. http://www.matronics.com/contribution =========
===
>
>
>
Message 6
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| Subject: | Re: Lean of Peak and other heresies |
In no particular order:
1. I do not attempt to operate LOP at high power settings. I think my injectors
aren't tuned well enough to get all the cylinders out of the red box at high
powers.
2. I did have to tune the injectors. Stock setup was not great in that regard.
3. Typical cruise for me is at 11,000'; all cylinders 10 to 30 F LOP; wide open
throttle; 2200-2300 RPM; 9.5 gal/hr fuel flow; 160 KTAS. CHT's are 325 F plus
or minus 10F or so (I removed the front air dams). This is two people plus bags.
Full gross and I lose a couple of knots.
--------
Bob Turner
RV-10 QB
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=428328#428328
Message 7
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| Subject: | Re: Lean of Peak and other heresies |
Funny thy tell folks to avoid when they have this to support just the
opposite.
To answer you questions, I always fly LOP, I tuned the injectors and can
get the plane to fly smoothly at around the 9.8-10.2gph range. Every
annual has shown a very clean and good looking cylinder. The A&P that
does the scope says it=99s the cleanest cylinder he sees all year.
He cant believe its because I fly LOP, but knows the certs he sees are
flying ROP because of carbs or POH instructions to be 50-100F ROP, and
is starting to believe that the 75F LOP I usually see is the reason for
the cleaner inspections.
I have about 300hrs on the narrow deck / eci cylinders and LOP works
very well for my CHT temps. I do not fly ROP ever (except TO and initial
climb), pretty much from 1K up I have the aircraft leaned.
Pascal
From: Les Kearney
Sent: Monday, August 11, 2014 7:18 PM
Subject: Re: RV10-List: Lean of Peak and other heresies
Hi Pascal
Here is a link to the monograph I hot from Lycoming at KOSH.
http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
Cheers
Les
Sent from my iPhone
On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
Plainly put the lycoming rep was uneducated on the Lycoming stance:
http://www.avweb.com/news/maint/182849-1.html?redirected=1
Lie #7:
Aggressive leaning results in burned valves and detonation.
Fear of the red knob is one of the most pernicious areas of
misinformation among general aviation pilots. Most pilots operate way
too rich most of the time, and do so because of the mistaken belief that
leaning will harm their engine. The result is usually trouble: fouled
spark plugs, accelerated exhaust valve guide wear, and stuck exhaust
valves.
Lycoming engine Lycoming has long authorized leaning to peak EGT at
any cruise setting up to 75% power. TCM authorizes leaning to peak EGT
up to 65%, and its latest recommendations even endorse lean-of-peak
operation for many big-bore engines, provided the engines will run
smoothly when operated that lean.
Contrary to popular belief, aggressive leaning doesn't cause burned
valves. Most burned valves are the result of excessive valve guide wear
or valve stem contamination.
Aggressive leaning doesn't cause detonation, either. Most of our
engines are incapable of detonation at cruise power settings, provided
that we don't exceed CHT red-line or try to burn contaminated fuel.
Furthermore, recent tests on Lycoming engines by ASTM revealed this
fascinating result: detonation is most likely to occur at a mixture
setting 11% richer than stoichiometric (i.e., substantially richer than
peak EGT).
Lean as aggressively as the book allows. For Lycomings, that means
peak EGT at all cruise power settings to 75%. For Continentals, lean to
peak EGT up to 65%, 50=C2=B0F rich of peak at 75%. For turbocharged
engines, also limit TIT to 1600=C2=B0F.
Lean during all ground operations except for engine start. It is
particularly important to lean for taxi and runup. Since EGT is usually
off-scale at idle power, the best method is to lean for peak RPM at
idle.
Read through Lycoming=99s Key Operations- found on the lycoming
site. Plenty about leaning at 75% and lower and even a chart that says
they do not recommend LOP, but on the same page has:
pg38
6. Leaning to best economy mixture.
a. Set manifold pressure and RPM for the desired cruise power setting
per the aircraft POH/AFM.
b. Lean slowly in small steps, while monitoring instrumentation, to
peak TIT or maximum allowable TIT, whichever occurs first
<image[3].png>
than on pg 39:
Once cruise power has been set, leaning to best economy should be
standard procedure as damage to the engine will not occur from leaning
at cruise power settings.
-----Original Message-----
From: LES KEARNEY
Sent: Monday, August 11, 2014 6:09 PM
To: rv10-list@matronics.com
Subject: RV10-List: Lean of Peak and other heresies
Hi
At KOSH I received some very conflicted info on lean of peak ops with
an IO540.
Continental (admittedly not a Lyc IO540), had a wonderful simulation /
presentation about how to safely run LOP. Their position was to stay
under 65% power to avoid the "red Box".
Lycoming seemed to think that LOP was was a high risk venture that
most mere mortals should avoid like the plague. They even has a 2000
monograph that had a few veiled references to Gami.
Mike Busch was very much in support of LOP ops in either brand C or L
engines. His view was physics doesnt't change with the brand of engine.
So, given that we have now resolved how to properly prime lithium
batteries, I would be interested in hearing about first hand LOP
experiences. Has anyone experienced problems with LOP. Lycoming seems to
think that LOP requires more attention to detail than the average pilot
can muster when things busy. They also suggest that ROP at power
settings that match LOP power yields similar albeit somewhat higher fuel
flows. Does actual experience bear this out?
Any comments?
Cheers
Les
Inquiring minds need to know!
============
RV10-List Email Forum -
http://www.matronics.com/Navigator?RV10-List
============= sp; - MATRONICS WEB FORUMS -
============= sp; - List Contribution Web
Site - sp; -Matt Dralle, List Admin.
http://www.matronics.com/c=============
Message 8
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| Subject: | Re: Lean of Peak and other heresies |
Pascal has it right. Lycoming says you are too inattentive, too dumb and
basically incapable of operating lean of peak because a. their engineers
have never tried it
b. their engineers are too stupid to understand it
c. their lawyers perceive a little itty bitty risk that must be avoided
d. they wouldn't want to change from what they recommended 50 yrs ago.
I've operated my 200 hp Lycoming IO-360-A1A LOP for the past 12 yrs or 700
hours without a problem. Prior to that it had some valve sticking that
probably caused overload on the cam lobes that resulted in spalled cam
lobes and lifters. It is stock 8.7:1 compression requiring 100 octane
minimum...closer to detonation margin than an stock IO-540 260 hp at 8.5:1
compression.
The main thing is to understand that you have one reference point for ROP
(when the first cylinder peaks) and LOP (when the LAST cylinder peaks). I
normally run full throttle and 10-20 LOP anywhere above 6000 ft (~24" MAP).
Fuel consumption will be about 0.5 gph per cylinder less than same power
ROP.
75% for IO-540=195hp = ~13gph LOP.
65%=169hp=~11.3 gph
for normally aspirated engines between 8.5 and 8.7 to 1 compression when
LOP power=FF*15 (14.9 if you want that much precision)
On Mon, Aug 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca> wrote:
> Hi Pascal
>
> Here is a link to the monograph I hot from Lycoming at KOSH.
>
> http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
>
> Cheers
>
> Les
>
> Sent from my iPhone
>
> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
>
> Plainly put the lycoming rep was uneducated on the Lycoming stance:
> http://www.avweb.com/news/maint/182849-1.html?redirected=1
> Lie #7:
> Aggressive leaning results in burned valves and detonation.
>
> Fear of the red knob is one of the most pernicious areas of misinformatio
n
> among general aviation pilots. Most pilots operate way too rich most of t
he
> time, and do so because of the mistaken belief that leaning will harm the
ir
> engine. The result is usually trouble: fouled spark plugs, accelerated
> exhaust valve guide wear, and stuck exhaust valves.
>
> Lycoming engine Lycoming has long authorized leaning to peak EGT at any
> cruise setting up to 75% power. TCM authorizes leaning to peak EGT up to
> 65%, and its latest recommendations even endorse lean-of-peak operation f
or
> many big-bore engines, provided the engines will run smoothly when operat
ed
> that lean.
>
> Contrary to popular belief, aggressive leaning doesn't cause burned
> valves. Most burned valves are the result of excessive valve guide wear o
r
> valve stem contamination.
>
> Aggressive leaning doesn't cause detonation, either. Most of our engines
> are incapable of detonation at cruise power settings, provided that we
> don't exceed CHT red-line or try to burn contaminated fuel. Furthermore,
> recent tests on Lycoming engines by ASTM revealed this fascinating result
:
> detonation is most likely to occur at a mixture setting 11% richer than
> stoichiometric (i.e., substantially richer than peak EGT).
>
> Lean as aggressively as the book allows. For Lycomings, that means peak
> EGT at all cruise power settings to 75%. For Continentals, lean to peak E
GT
> up to 65%, 50=B0F rich of peak at 75%. For turbocharged engines, also lim
it
> TIT to 1600=B0F.
>
> Lean during all ground operations except for engine start. It is
> particularly important to lean for taxi and runup. Since EGT is usually
> off-scale at idle power, the best method is to lean for peak RPM at idle.
>
> Read through Lycoming's Key Operations- found on the lycoming site. Plent
y
> about leaning at 75% and lower and even a chart that says they do not
> recommend LOP, but on the same page has:
> pg38
> 6. Leaning to best economy mixture.
> a. Set manifold pressure and RPM for the desired cruise power setting per
> the aircraft POH/AFM.
> b. Lean slowly in small steps, while monitoring instrumentation, to peak
> TIT or maximum allowable TIT, whichever occurs first
> <image[3].png>
>
> than on pg 39:
> Once cruise power has been set, leaning to best economy should be standar
d
> procedure as damage to the engine will not occur from leaning at cruise
> power settings.
>
>
> -----Original Message-----
> From: LES KEARNEY
> Sent: Monday, August 11, 2014 6:09 PM
> To: rv10-list@matronics.com
> Subject: RV10-List: Lean of Peak and other heresies
>
>
> Hi
>
> At KOSH I received some very conflicted info on lean of peak ops with an
> IO540.
>
> Continental (admittedly not a Lyc IO540), had a wonderful simulation /
> presentation about how to safely run LOP. Their position was to stay unde
r
> 65% power to avoid the "red Box".
>
> Lycoming seemed to think that LOP was was a high risk venture that most
> mere mortals should avoid like the plague. They even has a 2000 monograph
> that had a few veiled references to Gami.
>
> Mike Busch was very much in support of LOP ops in either brand C or L
> engines. His view was physics doesnt't change with the brand of engine.
>
> So, given that we have now resolved how to properly prime lithium
> batteries, I would be interested in hearing about first hand LOP
> experiences. Has anyone experienced problems with LOP. Lycoming seems to
> think that LOP requires more attention to detail than the average pilot c
an
> muster when things busy. They also suggest that ROP at power settings tha
t
> match LOP power yields similar albeit somewhat higher fuel flows. Does
> actual experience bear this out?
>
> Any comments?
>
> Cheers
>
> Les
> Inquiring minds need to know!
>
> ============
> RV10-List Email Forum -
> http://www.matronics.com/Navigator?RV10-List =========
==== sp; -
> MATRONICS WEB FORUMS - ============= sp; - Lis
t Contribution Web Site -
> sp; -Matt Dralle, List Admin. http://www.matronics.com/
c============
>
>
> <http://www.matronics.com/contribution>
>
> *
>
===========
onics.com/Navigator?RV10-List>
===========
===========
om/contribution>
===========
>
> *
>
>
Message 9
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| Subject: | Re: Lean of Peak and other heresies |
I'm assuming it is fuel economy that motivates your operating at 55% power
LOP? Absolutely nothing wrong with it, and excellent speed for that power.
On Mon, Aug 11, 2014 at 7:31 PM, Bob Turner <bobturner@alum.rpi.edu> wrote:
>
> In no particular order:
> 1. I do not attempt to operate LOP at high power settings. I think my
> injectors aren't tuned well enough to get all the cylinders out of the red
> box at high powers.
> 2. I did have to tune the injectors. Stock setup was not great in that
> regard.
> 3. Typical cruise for me is at 11,000'; all cylinders 10 to 30 F LOP; wide
> open throttle; 2200-2300 RPM; 9.5 gal/hr fuel flow; 160 KTAS. CHT's are 325
> F plus or minus 10F or so (I removed the front air dams). This is two
> people plus bags. Full gross and I lose a couple of knots.
>
> --------
> Bob Turner
> RV-10 QB
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=428328#428328
>
>
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| Subject: | Re: Lean of Peak and other heresies |
Hmmm
Has anyone run LOP with 9:1 compression cylinders?
For the IO540, is there a power setting analogous to the Brand C 65% power s
etting that eliminates the red box risk?
Cheers
Les
Sent from my iPhone
> On Aug 11, 2014, at 8:53 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>
> Pascal has it right. Lycoming says you are too inattentive, too dumb and b
asically incapable of operating lean of peak because a. their engineers have
never tried it
> b. their engineers are too stupid to understand it
> c. their lawyers perceive a little itty bitty risk that must be avoided
> d. they wouldn't want to change from what they recommended 50 yrs ago.
> I've operated my 200 hp Lycoming IO-360-A1A LOP for the past 12 yrs or 700
hours without a problem. Prior to that it had some valve sticking that pro
bably caused overload on the cam lobes that resulted in spalled cam lobes an
d lifters. It is stock 8.7:1 compression requiring 100 octane minimum...clos
er to detonation margin than an stock IO-540 260 hp at 8.5:1 compression.
> The main thing is to understand that you have one reference point for ROP (
when the first cylinder peaks) and LOP (when the LAST cylinder peaks). I nor
mally run full throttle and 10-20 LOP anywhere above 6000 ft (~24" MAP). Fue
l consumption will be about 0.5 gph per cylinder less than same power ROP.
> 75% for IO-540=195hp = ~13gph LOP.
> 65%=169hp=~11.3 gph
> for normally aspirated engines between 8.5 and 8.7 to 1 compression when L
OP power=FF*15 (14.9 if you want that much precision)
>
>
>> On Mon, Aug 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca> wrote:
>> Hi Pascal
>>
>> Here is a link to the monograph I hot from Lycoming at KOSH.
>>
>> http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
>>
>> Cheers
>>
>> Les
>>
>> Sent from my iPhone
>>
>>> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
>>>
>>> Plainly put the lycoming rep was uneducated on the Lycoming stance:
>>> http://www.avweb.com/news/maint/182849-1.html?redirected=1
>>> Lie #7:
>>> Aggressive leaning results in burned valves and detonation.
>>>
>>> Fear of the red knob is one of the most pernicious areas of misinformati
on among general aviation pilots. Most pilots operate way too rich most of t
he time, and do so because of the mistaken belief that leaning will harm the
ir engine. The result is usually trouble: fouled spark plugs, accelerated ex
haust valve guide wear, and stuck exhaust valves.
>>>
>>> Lycoming engine Lycoming has long authorized leaning to peak EGT at any c
ruise setting up to 75% power. TCM authorizes leaning to peak EGT up to 65%,
and its latest recommendations even endorse lean-of-peak operation for many
big-bore engines, provided the engines will run smoothly when operated that
lean.
>>>
>>> Contrary to popular belief, aggressive leaning doesn't cause burned valv
es. Most burned valves are the result of excessive valve guide wear or valve
stem contamination.
>>>
>>> Aggressive leaning doesn't cause detonation, either. Most of our engines
are incapable of detonation at cruise power settings, provided that we don'
t exceed CHT red-line or try to burn contaminated fuel. Furthermore, recent t
ests on Lycoming engines by ASTM revealed this fascinating result: detonatio
n is most likely to occur at a mixture setting 11% richer than stoichiometri
c (i.e., substantially richer than peak EGT).
>>>
>>> Lean as aggressively as the book allows. For Lycomings, that means peak E
GT at all cruise power settings to 75%. For Continentals, lean to peak EGT u
p to 65%, 50=C2=B0F rich of peak at 75%. For turbocharged engines, also limi
t TIT to 1600=C2=B0F.
>>>
>>> Lean during all ground operations except for engine start. It is particu
larly important to lean for taxi and runup. Since EGT is usually off-scale a
t idle power, the best method is to lean for peak RPM at idle.
>>>
>>> Read through Lycoming=99s Key Operations- found on the lycoming si
te. Plenty about leaning at 75% and lower and even a chart that says they do
not recommend LOP, but on the same page has:
>>> pg38
>>> 6. Leaning to best economy mixture.
>>> a. Set manifold pressure and RPM for the desired cruise power setting pe
r the aircraft POH/AFM.
>>> b. Lean slowly in small steps, while monitoring instrumentation, to peak
TIT or maximum allowable TIT, whichever occurs first
>>> <image[3].png>
>>>
>>> than on pg 39:
>>> Once cruise power has been set, leaning to best economy should be standa
rd procedure as damage to the engine will not occur from leaning at cruise p
ower settings.
>>>
>>>
>>> -----Original Message-----
>>> From: LES KEARNEY
>>> Sent: Monday, August 11, 2014 6:09 PM
>>> To: rv10-list@matronics.com
>>> Subject: RV10-List: Lean of Peak and other heresies
>>>
>>>
>>> Hi
>>>
>>> At KOSH I received some very conflicted info on lean of peak ops with an
IO540.
>>>
>>> Continental (admittedly not a Lyc IO540), had a wonderful simulation / p
resentation about how to safely run LOP. Their position was to stay under 65
% power to avoid the "red Box".
>>>
>>> Lycoming seemed to think that LOP was was a high risk venture that most m
ere mortals should avoid like the plague. They even has a 2000 monograph tha
t had a few veiled references to Gami.
>>>
>>> Mike Busch was very much in support of LOP ops in either brand C or L en
gines. His view was physics doesnt't change with the brand of engine.
>>>
>>> So, given that we have now resolved how to properly prime lithium batter
ies, I would be interested in hearing about first hand LOP experiences. Has a
nyone experienced problems with LOP. Lycoming seems to think that LOP requir
es more attention to detail than the average pilot can muster when things bu
sy. They also suggest that ROP at power settings that match LOP power yields
similar albeit somewhat higher fuel flows. Does actual experience bear this
out?
>>>
>>> Any comments?
>>>
>>> Cheers
>>>
>>> Les
>>> Inquiring minds need to know!
>>>
>>> ============
>>> RV10-List Email Forum -
>>> http://www.matronics.com/Navigator?RV10-List =========
==== sp; - MATRONICS WEB FORUMS - ===========
== sp; - List Contribution Web Site - sp; -Matt Dra
lle, List Admin. http://www.matronics.com/c===========
=
>>
>>
>> get="_blank">http://www.matronics.com/Navigator?RV10-List
>> tp://forums.matronics.com
>> _blank">http://www.matronics.com/contribution
>>
>
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
Message 11
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| Subject: | Re: Lean of Peak and other heresies |
Les,
Just curious why you would want 9:1 compression when the availability of
true 100 octane fuel into the future is questionable?
The gain in horsepower might help a little on really short or high
elevation airports, but it isn't going to do much for cruise speed.
I don't know anyone that thinks the acceleration and climb of the stock 260
is inadequate for most any normal operation.
The physics is the same. 8.7:1 has almost zero red box and 8.5 to 1 even
less. Higher compression just means the red box is bigger and needs more
attention, just like a turbo would.
On Mon, Aug 11, 2014 at 8:21 PM, Les Kearney <kearney@shaw.ca> wrote:
> Hmmm
>
> Has anyone run LOP with 9:1 compression cylinders?
>
> For the IO540, is there a power setting analogous to the Brand C 65% powe
r
> setting that eliminates the red box risk?
>
> Cheers
>
> Les
>
> Sent from my iPhone
>
> On Aug 11, 2014, at 8:53 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>
> Pascal has it right. Lycoming says you are too inattentive, too dumb and
> basically incapable of operating lean of peak because a. their engineers
> have never tried it
> b. their engineers are too stupid to understand it
> c. their lawyers perceive a little itty bitty risk that must be avoided
> d. they wouldn't want to change from what they recommended 50 yrs ago.
> I've operated my 200 hp Lycoming IO-360-A1A LOP for the past 12 yrs or 70
0
> hours without a problem. Prior to that it had some valve sticking that
> probably caused overload on the cam lobes that resulted in spalled cam
> lobes and lifters. It is stock 8.7:1 compression requiring 100 octane
> minimum...closer to detonation margin than an stock IO-540 260 hp at 8.5:
1
> compression.
> The main thing is to understand that you have one reference point for ROP
> (when the first cylinder peaks) and LOP (when the LAST cylinder peaks). I
> normally run full throttle and 10-20 LOP anywhere above 6000 ft (~24" MAP
).
> Fuel consumption will be about 0.5 gph per cylinder less than same power
> ROP.
> 75% for IO-540=195hp = ~13gph LOP.
> 65%=169hp=~11.3 gph
> for normally aspirated engines between 8.5 and 8.7 to 1 compression when
> LOP power=FF*15 (14.9 if you want that much precision)
>
>
> On Mon, Aug 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca> wrote:
>
>> Hi Pascal
>>
>> Here is a link to the monograph I hot from Lycoming at KOSH.
>>
>> http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
>>
>> Cheers
>>
>> Les
>>
>> Sent from my iPhone
>>
>> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
>>
>> Plainly put the lycoming rep was uneducated on the Lycoming stance:
>> http://www.avweb.com/news/maint/182849-1.html?redirected=1
>> Lie #7:
>> Aggressive leaning results in burned valves and detonation.
>>
>> Fear of the red knob is one of the most pernicious areas of
>> misinformation among general aviation pilots. Most pilots operate way to
o
>> rich most of the time, and do so because of the mistaken belief that
>> leaning will harm their engine. The result is usually trouble: fouled sp
ark
>> plugs, accelerated exhaust valve guide wear, and stuck exhaust valves.
>>
>> Lycoming engine Lycoming has long authorized leaning to peak EGT at any
>> cruise setting up to 75% power. TCM authorizes leaning to peak EGT up to
>> 65%, and its latest recommendations even endorse lean-of-peak operation
for
>> many big-bore engines, provided the engines will run smoothly when opera
ted
>> that lean.
>>
>> Contrary to popular belief, aggressive leaning doesn't cause burned
>> valves. Most burned valves are the result of excessive valve guide wear
or
>> valve stem contamination.
>>
>> Aggressive leaning doesn't cause detonation, either. Most of our engines
>> are incapable of detonation at cruise power settings, provided that we
>> don't exceed CHT red-line or try to burn contaminated fuel. Furthermore,
>> recent tests on Lycoming engines by ASTM revealed this fascinating resul
t:
>> detonation is most likely to occur at a mixture setting 11% richer than
>> stoichiometric (i.e., substantially richer than peak EGT).
>>
>> Lean as aggressively as the book allows. For Lycomings, that means peak
>> EGT at all cruise power settings to 75%. For Continentals, lean to peak
EGT
>> up to 65%, 50=B0F rich of peak at 75%. For turbocharged engines, also li
mit
>> TIT to 1600=B0F.
>>
>> Lean during all ground operations except for engine start. It is
>> particularly important to lean for taxi and runup. Since EGT is usually
>> off-scale at idle power, the best method is to lean for peak RPM at idle
.
>>
>> Read through Lycoming's Key Operations- found on the lycoming site.
>> Plenty about leaning at 75% and lower and even a chart that says they do
>> not recommend LOP, but on the same page has:
>> pg38
>> 6. Leaning to best economy mixture.
>> a. Set manifold pressure and RPM for the desired cruise power setting pe
r
>> the aircraft POH/AFM.
>> b. Lean slowly in small steps, while monitoring instrumentation, to peak
>> TIT or maximum allowable TIT, whichever occurs first
>> <image[3].png>
>>
>> than on pg 39:
>> Once cruise power has been set, leaning to best economy should be
>> standard procedure as damage to the engine will not occur from leaning a
t
>> cruise power settings.
>>
>>
>> -----Original Message-----
>> From: LES KEARNEY
>> Sent: Monday, August 11, 2014 6:09 PM
>> To: rv10-list@matronics.com
>> Subject: RV10-List: Lean of Peak and other heresies
>>
>>
>> Hi
>>
>> At KOSH I received some very conflicted info on lean of peak ops with an
>> IO540.
>>
>> Continental (admittedly not a Lyc IO540), had a wonderful simulation /
>> presentation about how to safely run LOP. Their position was to stay und
er
>> 65% power to avoid the "red Box".
>>
>> Lycoming seemed to think that LOP was was a high risk venture that most
>> mere mortals should avoid like the plague. They even has a 2000 monograp
h
>> that had a few veiled references to Gami.
>>
>> Mike Busch was very much in support of LOP ops in either brand C or L
>> engines. His view was physics doesnt't change with the brand of engine.
>>
>> So, given that we have now resolved how to properly prime lithium
>> batteries, I would be interested in hearing about first hand LOP
>> experiences. Has anyone experienced problems with LOP. Lycoming seems to
>> think that LOP requires more attention to detail than the average pilot
can
>> muster when things busy. They also suggest that ROP at power settings th
at
>> match LOP power yields similar albeit somewhat higher fuel flows. Does
>> actual experience bear this out?
>>
>> Any comments?
>>
>> Cheers
>>
>> Les
>> Inquiring minds need to know!
>>
>> ============
>> RV10-List Email Forum -
>> http://www.matronics.com/Navigator?RV10-List =========
==== sp; -
>> MATRONICS WEB FORUMS - ============= sp; - Li
st Contribution Web Site -
>> sp; -Matt Dralle, List Admin. http://www.matronics.com
/c============
>>
>>
>>
>>
>> <http://www.matronics.com/contribution>
>>
>> *
>>
>> get="_blank">http://www.matronics.com/Navigator?RV10-List <http://www.
matronics.com/Navigator?RV10-List>
>> tp://forums.matronics.com <http://forums.matronics.com>
>> _blank">http://www.matronics.com/contribution <http://www.matronics.com/
contribution>
>>
>> *
>>
>>
> *
>
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D
> List"">http://www.matronics.com/Navigator?RV10-List <http://www.matronics
.com/Navigator?RV10-List>
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D
> //forums.matronics.com <http://forums.matronics.com>
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D
> ot;">http://www.matronics.com/contribution <http://www.matronics.com/cont
ribution>
> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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>
> *
>
> *
>
===========
onics.com/Navigator?RV10-List>
===========
===========
om/contribution>
===========
>
> *
>
>
Message 12
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| Subject: | Re: Lean of Peak and other heresies |
This is right on based on my experience as well. Our -10 has over 1,300 hrs o
n ECI narrow deck cylinders running LOP exactly as Pascal describes. Tuned i
njectors help. Some engines can't even get LOP smoothly without them. Some d
o, but it helps in all cases. That is why I started stocking the AFP restric
tors. I recommend it to everybody I can. It's nice to be able to avoid the G
ami prices with our experimentals.
Jesse Saint
Saint Aviation, Inc.
352-427-0285
jesse@saintaviation.com
Sent from my iPad
> On Aug 11, 2014, at 10:53 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>
> Pascal has it right. Lycoming says you are too inattentive, too dumb and b
asically incapable of operating lean of peak because a. their engineers have
never tried it
> b. their engineers are too stupid to understand it
> c. their lawyers perceive a little itty bitty risk that must be avoided
> d. they wouldn't want to change from what they recommended 50 yrs ago.
> I've operated my 200 hp Lycoming IO-360-A1A LOP for the past 12 yrs or 700
hours without a problem. Prior to that it had some valve sticking that pro
bably caused overload on the cam lobes that resulted in spalled cam lobes an
d lifters. It is stock 8.7:1 compression requiring 100 octane minimum...clos
er to detonation margin than an stock IO-540 260 hp at 8.5:1 compression.
> The main thing is to understand that you have one reference point for ROP (
when the first cylinder peaks) and LOP (when the LAST cylinder peaks). I nor
mally run full throttle and 10-20 LOP anywhere above 6000 ft (~24" MAP). Fue
l consumption will be about 0.5 gph per cylinder less than same power ROP.
> 75% for IO-540=195hp = ~13gph LOP.
> 65%=169hp=~11.3 gph
> for normally aspirated engines between 8.5 and 8.7 to 1 compression when L
OP power=FF*15 (14.9 if you want that much precision)
>
>
>> On Mon, Aug 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca> wrote:
>> Hi Pascal
>>
>> Here is a link to the monograph I hot from Lycoming at KOSH.
>>
>> http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
>>
>> Cheers
>>
>> Les
>>
>> Sent from my iPhone
>>
>>> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
>>>
>>> Plainly put the lycoming rep was uneducated on the Lycoming stance:
>>> http://www.avweb.com/news/maint/182849-1.html?redirected=1
>>> Lie #7:
>>> Aggressive leaning results in burned valves and detonation.
>>>
>>> Fear of the red knob is one of the most pernicious areas of misinformati
on among general aviation pilots. Most pilots operate way too rich most of t
he time, and do so because of the mistaken belief that leaning will harm the
ir engine. The result is usually trouble: fouled spark plugs, accelerated ex
haust valve guide wear, and stuck exhaust valves.
>>>
>>> Lycoming engine Lycoming has long authorized leaning to peak EGT at any c
ruise setting up to 75% power. TCM authorizes leaning to peak EGT up to 65%,
and its latest recommendations even endorse lean-of-peak operation for many
big-bore engines, provided the engines will run smoothly when operated that
lean.
>>>
>>> Contrary to popular belief, aggressive leaning doesn't cause burned valv
es. Most burned valves are the result of excessive valve guide wear or valve
stem contamination.
>>>
>>> Aggressive leaning doesn't cause detonation, either. Most of our engines
are incapable of detonation at cruise power settings, provided that we don'
t exceed CHT red-line or try to burn contaminated fuel. Furthermore, recent t
ests on Lycoming engines by ASTM revealed this fascinating result: detonatio
n is most likely to occur at a mixture setting 11% richer than stoichiometri
c (i.e., substantially richer than peak EGT).
>>>
>>> Lean as aggressively as the book allows. For Lycomings, that means peak E
GT at all cruise power settings to 75%. For Continentals, lean to peak EGT u
p to 65%, 50=C2=B0F rich of peak at 75%. For turbocharged engines, also limi
t TIT to 1600=C2=B0F.
>>>
>>> Lean during all ground operations except for engine start. It is particu
larly important to lean for taxi and runup. Since EGT is usually off-scale a
t idle power, the best method is to lean for peak RPM at idle.
>>>
>>> Read through Lycoming=99s Key Operations- found on the lycoming si
te. Plenty about leaning at 75% and lower and even a chart that says they do
not recommend LOP, but on the same page has:
>>> pg38
>>> 6. Leaning to best economy mixture.
>>> a. Set manifold pressure and RPM for the desired cruise power setting pe
r the aircraft POH/AFM.
>>> b. Lean slowly in small steps, while monitoring instrumentation, to peak
TIT or maximum allowable TIT, whichever occurs first
>>> <image[3].png>
>>>
>>> than on pg 39:
>>> Once cruise power has been set, leaning to best economy should be standa
rd procedure as damage to the engine will not occur from leaning at cruise p
ower settings.
>>>
>>>
>>> -----Original Message-----
>>> From: LES KEARNEY
>>> Sent: Monday, August 11, 2014 6:09 PM
>>> To: rv10-list@matronics.com
>>> Subject: RV10-List: Lean of Peak and other heresies
>>>
>>>
>>> Hi
>>>
>>> At KOSH I received some very conflicted info on lean of peak ops with an
IO540.
>>>
>>> Continental (admittedly not a Lyc IO540), had a wonderful simulation / p
resentation about how to safely run LOP. Their position was to stay under 65
% power to avoid the "red Box".
>>>
>>> Lycoming seemed to think that LOP was was a high risk venture that most m
ere mortals should avoid like the plague. They even has a 2000 monograph tha
t had a few veiled references to Gami.
>>>
>>> Mike Busch was very much in support of LOP ops in either brand C or L en
gines. His view was physics doesnt't change with the brand of engine.
>>>
>>> So, given that we have now resolved how to properly prime lithium batter
ies, I would be interested in hearing about first hand LOP experiences. Has a
nyone experienced problems with LOP. Lycoming seems to think that LOP requir
es more attention to detail than the average pilot can muster when things bu
sy. They also suggest that ROP at power settings that match LOP power yields
similar albeit somewhat higher fuel flows. Does actual experience bear this
out?
>>>
>>> Any comments?
>>>
>>> Cheers
>>>
>>> Les
>>> Inquiring minds need to know!
>>>
>>> ============
>>> RV10-List Email Forum -
>>> http://www.matronics.com/Navigator?RV10-List =========
==== sp; - MATRONICS WEB FORUMS - ===========
== sp; - List Contribution Web Site - sp; -Matt Drall
e, List Admin. http://www.matronics.com/c============
>>
>>
>> get="_blank">http://www.matronics.com/Navigator?RV10-List
>> tp://forums.matronics.com
>> _blank">http://www.matronics.com/contribution
>>
>
>
>
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Message 13
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| Subject: | Re: Lean of Peak and other heresies |
How about 9:5 compression?=C2- That's what I have, and I fly LOP everywhe
re.=C2- Lot's of hp, 3 blade prop... cruise at 1/2 throttle (at 10,500',
instead of WOT providing 21.3 inches, I'm around 18.5") and between 2,000 a
nd 2,100 rpm. I'm sure Kelley will tell us what % power that setting is.=C2
- Before some of you say "he can't get 21.3" at 10,500, I only get 20.3".
... you can if you have a 4" forward facing servo with cold air induction a
nd an F1 Rocket scoop.=0AWith these settings we cruise fast enough (156kts)
, have a low fuel burn, and the engine temps and my wallet are very happy.
=0ADon Mc=0A=0A=0A=0A________________________________=0A From: Les Kearney
<kearney@shaw.ca>=0ATo: "rv10-list@matronics.com" <rv10-list@matronics.com>
=0ASent: Monday, August 11, 2014 10:21 PM=0ASubject: Re: RV10-List: Lean o
f Peak and other heresies=0A =0A=0A=0AHmmm=0A=0AHas anyone run LOP with 9:1
compression cylinders?=0A=0AFor the IO540, is there a power setting analog
ous to the Brand C 65% power setting that eliminates the red box risk?=0A
=0ACheers=0A=0ALes=0A=0ASent from my iPhone=0A=0AOn Aug 11, 2014, at 8:53 P
M, Kelly McMullen <apilot2@gmail.com> wrote:=0A=0A=0APascal has it right. L
ycoming says you are too inattentive, too dumb and basically incapable of o
perating lean of peak because a. their engineers have never tried it=0A>b.
their engineers are too stupid to understand it=0A>c. their lawyers perceiv
e a little itty bitty risk that must be avoided=0A>d. they wouldn't want to
change from what they recommended 50 yrs ago.=0A>I've operated my 200 hp L
ycoming IO-360-A1A LOP for the past 12 yrs or 700 hours without a problem.
=C2- Prior to that it had some valve sticking that probably caused overlo
ad on the cam lobes that resulted in spalled cam lobes and lifters. It is s
tock 8.7:1 compression requiring 100 octane minimum...closer to detonation
margin than an stock IO-540 260 hp at 8.5:1 compression.=0A>The main thing
is to understand that you have one reference point for ROP (when the first
cylinder peaks) and LOP (when the LAST cylinder peaks). I normally run full
throttle and 10-20 LOP anywhere above 6000 ft (~24" MAP). Fuel consumption
will be about 0.5 gph per cylinder less than same power ROP.=0A>75% for IO
-540=195hp = ~13gph LOP.=0A>65%=169hp=~11.3 gph=0A>for normally asp
irated engines between 8.5 and 8.7 to 1 compression when LOP power=FF*15
=C2- (14.9 if you want that much precision)=0A>=0A>=0A>=0A>=0A>On Mon, Au
g 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca> wrote:=0A>=0A>Hi Pasca
l=0A>>=0A>>=0A>>Here is a link to the monograph I hot from Lycoming at KOSH
.=C2-=0A>>=0A>>=0A>>http://www.shamrockairservices.com/images/LEANING%20T
ECHNIQUES.pdf=0A>>=0A>>=0A>>Cheers=0A>>=0A>>=0A>>Les=0A>>=0A>>Sent from my
iPhone=0A>>=0A>>On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com>
wrote:=0A>>=0A>>=0A>>Plainly put the lycoming rep was uneducated on the Lyc
oming stance:=0A>>>http://www.avweb.com/news/maint/182849-1.html?redirected
=1=0A>>>Lie #7:=0A>>>Aggressive leaning results in burned valves and deto
nation.=0A>>>=C2-=0A>>>Fear of the red knob is one of the most pernicious
areas of misinformation =0Aamong general aviation pilots. Most pilots oper
ate way too rich most of the =0Atime, and do so because of the mistaken bel
ief that leaning will harm their =0Aengine. The result is usually trouble:
fouled spark plugs, accelerated exhaust =0Avalve guide wear, and stuck exha
ust valves.=0A>>>=C2-=0A>>>Lycoming engine Lycoming has long authorized l
eaning to peak EGT at any =0Acruise setting up to 75% power. TCM authorizes
leaning to peak EGT up to 65%, =0Aand its latest recommendations even endo
rse lean-of-peak operation for many =0Abig-bore engines, provided the engin
es will run smoothly when operated that =0Alean.=0A>>>=C2-=0A>>>Contrary
to popular belief, aggressive leaning doesn't cause burned valves. =0AMost
burned valves are the result of excessive valve guide wear or valve stem
=0Acontamination.=0A>>>=C2-=0A>>>Aggressive leaning doesn't cause detonat
ion, either. Most of our engines =0Aare incapable of detonation at cruise p
ower settings, provided that we don't =0Aexceed CHT red-line or try to burn
contaminated fuel. Furthermore, recent tests =0Aon Lycoming engines by AST
M revealed this fascinating result: detonation is most =0Alikely to occur a
t a mixture setting 11% richer than stoichiometric (i.e., =0Asubstantially
richer than peak EGT).=0A>>>=C2-=0A>>>Lean as aggressively as the book al
lows. For Lycomings, that means peak EGT =0Aat all cruise power settings to
75%. For Continentals, lean to peak EGT up to =0A65%, 50=C2=B0F rich of pe
ak at 75%. For turbocharged engines, also limit TIT to =0A1600=C2=B0F.=0A>>
>=C2-=0A>>>Lean during all ground operations except for engine start. It
is =0Aparticularly important to lean for taxi and runup. Since EGT is usual
ly =0Aoff-scale at idle power, the best method is to lean for peak RPM at i
dle. =0A>>>=C2-=0A>>>Read through Lycoming=99s Key Operations- foun
d on the lycoming site. Plenty =0Aabout leaning at 75% and lower and even a
chart that says they do not recommend =0ALOP, but on the same page has:
=0A>>>pg38=0A>>>6. Leaning to best economy mixture.=0A>>>a. Set manifold pr
essure and RPM for the desired cruise power setting per =0Athe aircraft POH
/AFM.=0A>>>b. Lean slowly in small steps, while monitoring instrumentation,
to peak =0ATIT or maximum allowable TIT, whichever occurs first=0A>>><imag
e[3].png>=0A>>>=C2-=0A>>>than on pg 39:=0A>>>Once cruise power has been s
et, leaning to best economy should be standard =0Aprocedure as damage to th
e engine will not occur from leaning at cruise power =0Asettings.=0A>>>=C2
-=0A>>>=C2-=0A>>>-----Original Message----- =0A>>>From: LES KEARNEY =0A
>>>Sent: Monday, August 11, 2014 6:09 PM =0A>>>To: rv10-list@matronics.com
=0A>>>Subject: RV10-List: Lean of Peak and other heresies =0A>>>=C2-=0A>>
-=0A>>>Hi=0A>>>=C2-=0A>>>At KOSH I received some very conflicted info o
n lean of peak ops with an =0AIO540. =0A>>>=C2-=0A>>>Continental (admitte
dly not a Lyc IO540), had a wonderful simulation / =0Apresentation about ho
w to safely run LOP. Their position was to stay under 65% =0Apower to avoid
the "red Box". =0A>>>=C2-=0A>>>Lycoming seemed to think that LOP was was
a high risk venture that most =0Amere mortals should avoid like the plague
. They even has a 2000 monograph that =0Ahad a few veiled references to Gam
i.=0A>>>=C2-=0A>>>Mike Busch was very much in support of LOP ops in eithe
r brand C or L =0Aengines. His view was physics doesnt't change with the br
and of engine.=0A>>>=C2-=0A>>>So, given that we have now resolved how to
properly prime lithium =0Abatteries, I would be interested in hearing about
first hand LOP experiences. =0AHas anyone experienced problems with LOP. L
ycoming seems to think that LOP =0Arequires more attention to detail than t
he average pilot can muster when things =0Abusy. They also suggest that ROP
at power settings that match LOP power yields =0Asimilar albeit somewhat h
igher fuel flows. Does actual experience bear this =0Aout?=0A>>>=C2-=0A>>
>Any comments?=0A>>>=C2-=0A>>>Cheers=0A>>>=C2-=0A>>>Les=0A>>>Inquiring
minds need to know!=0A>>>=C2-=0A=============
=0ARV10-List =0AEmail Forum -http://www.matronics.com/Navigator?RV10-List
==============0Asp;=C2-=C2-=C2- =0A- MATRON
ICS WEB FORUMS -=0A==============0Asp;=C2- =0A-
List Contribution Web Site -=0Asp;=C2-=C2-=C2-=C2-=C2-=C2-=C2
-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2- =0A-M
att Dralle, List Admin. http://www.matronics.com/c========
===== =0A>>>=C2-=0A>>>=C2-=0A>>>=C2-=0A>>get="_blank">htt
p://www.matronics.com/Navigator?RV10-List tp://forums.matronics.com=0A_blan
k">http://www.matronics.com/contribution =0A>=0A>D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=0AList"">http://www.matr
onics.com/Navigator?RV10-List=0AD=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=0A//forums.matronics.com=0AD=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=0Aot;">ht
tp://www.matronics.com/contribution=0AD=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=
Message 14
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| Subject: | Re: Lean of Peak and other heresies |
Hi Kelly
I am not too fussed about 100ll. As well, I plan to fly over the rocks to th
e west.
Cheers
Les
Sent from my iPhone
> On Aug 11, 2014, at 9:47 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>
> Les,
> Just curious why you would want 9:1 compression when the availability of t
rue 100 octane fuel into the future is questionable?
> The gain in horsepower might help a little on really short or high elevati
on airports, but it isn't going to do much for cruise speed.
> I don't know anyone that thinks the acceleration and climb of the stock 26
0 is inadequate for most any normal operation.
> The physics is the same. 8.7:1 has almost zero red box and 8.5 to 1 even l
ess. Higher compression just means the red box is bigger and needs more atte
ntion, just like a turbo would.
>
>
>> On Mon, Aug 11, 2014 at 8:21 PM, Les Kearney <kearney@shaw.ca> wrote:
>> Hmmm
>>
>> Has anyone run LOP with 9:1 compression cylinders?
>>
>> For the IO540, is there a power setting analogous to the Brand C 65% powe
r setting that eliminates the red box risk?
>>
>> Cheers
>>
>> Les
>>
>> Sent from my iPhone
>>
>>> On Aug 11, 2014, at 8:53 PM, Kelly McMullen <apilot2@gmail.com> wrote:
>>>
>>> Pascal has it right. Lycoming says you are too inattentive, too dumb and
basically incapable of operating lean of peak because a. their engineers ha
ve never tried it
>>> b. their engineers are too stupid to understand it
>>> c. their lawyers perceive a little itty bitty risk that must be avoided
>>> d. they wouldn't want to change from what they recommended 50 yrs ago.
>>> I've operated my 200 hp Lycoming IO-360-A1A LOP for the past 12 yrs or 7
00 hours without a problem. Prior to that it had some valve sticking that p
robably caused overload on the cam lobes that resulted in spalled cam lobes a
nd lifters. It is stock 8.7:1 compression requiring 100 octane minimum...clo
ser to detonation margin than an stock IO-540 260 hp at 8.5:1 compression.
>>> The main thing is to understand that you have one reference point for RO
P (when the first cylinder peaks) and LOP (when the LAST cylinder peaks). I n
ormally run full throttle and 10-20 LOP anywhere above 6000 ft (~24" MAP). Fu
el consumption will be about 0.5 gph per cylinder less than same power ROP.
>>> 75% for IO-540=195hp = ~13gph LOP.
>>> 65%=169hp=~11.3 gph
>>> for normally aspirated engines between 8.5 and 8.7 to 1 compression when
LOP power=FF*15 (14.9 if you want that much precision)
>>>
>>>
>>>> On Mon, Aug 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca> wrote:
>>>> Hi Pascal
>>>>
>>>> Here is a link to the monograph I hot from Lycoming at KOSH.
>>>>
>>>> http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
>>>>
>>>> Cheers
>>>>
>>>> Les
>>>>
>>>> Sent from my iPhone
>>>>
>>>>> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com> wrote:
>>>>>
>>>>> Plainly put the lycoming rep was uneducated on the Lycoming stance:
>>>>> http://www.avweb.com/news/maint/182849-1.html?redirected=1
>>>>> Lie #7:
>>>>> Aggressive leaning results in burned valves and detonation.
>>>>>
>>>>> Fear of the red knob is one of the most pernicious areas of misinforma
tion among general aviation pilots. Most pilots operate way too rich most of
the time, and do so because of the mistaken belief that leaning will harm t
heir engine. The result is usually trouble: fouled spark plugs, accelerated e
xhaust valve guide wear, and stuck exhaust valves.
>>>>>
>>>>> Lycoming engine Lycoming has long authorized leaning to peak EGT at an
y cruise setting up to 75% power. TCM authorizes leaning to peak EGT up to 6
5%, and its latest recommendations even endorse lean-of-peak operation for m
any big-bore engines, provided the engines will run smoothly when operated t
hat lean.
>>>>>
>>>>> Contrary to popular belief, aggressive leaning doesn't cause burned va
lves. Most burned valves are the result of excessive valve guide wear or va
lve stem contamination.
>>>>>
>>>>> Aggressive leaning doesn't cause detonation, either. Most of our engin
es are incapable of detonation at cruise power settings, provided that we do
n't exceed CHT red-line or try to burn contaminated fuel. Furthermore, recen
t tests on Lycoming engines by ASTM revealed this fascinating result: detona
tion is most likely to occur at a mixture setting 11% richer than stoichiome
tric (i.e., substantially richer than peak EGT).
>>>>>
>>>>> Lean as aggressively as the book allows. For Lycomings, that means pea
k EGT at all cruise power settings to 75%. For Continentals, lean to peak EG
T up to 65%, 50=C2=B0F rich of peak at 75%. For turbocharged engines, also l
imit TIT to 1600=C2=B0F.
>>>>>
>>>>> Lean during all ground operations except for engine start. It is parti
cularly important to lean for taxi and runup. Since EGT is usually off-scale
at idle power, the best method is to lean for peak RPM at idle.
>>>>>
>>>>> Read through Lycoming=99s Key Operations- found on the lycoming s
ite. Plenty about leaning at 75% and lower and even a chart that says they d
o not recommend LOP, but on the same page has:
>>>>> pg38
>>>>> 6. Leaning to best economy mixture.
>>>>> a. Set manifold pressure and RPM for the desired cruise power setting p
er the aircraft POH/AFM.
>>>>> b. Lean slowly in small steps, while monitoring instrumentation, to pe
ak TIT or maximum allowable TIT, whichever occurs first
>>>>> <image[3].png>
>>>>>
>>>>> than on pg 39:
>>>>> Once cruise power has been set, leaning to best economy should be stan
dard procedure as damage to the engine will not occur from leaning at cruise
power settings.
>>>>>
>>>>>
>>>>> -----Original Message-----
>>>>> From: LES KEARNEY
>>>>> Sent: Monday, August 11, 2014 6:09 PM
>>>>> To: rv10-list@matronics.com
>>>>> Subject: RV10-List: Lean of Peak and other heresies
>>>>>
>>>>>
>>>>> Hi
>>>>>
>>>>> At KOSH I received some very conflicted info on lean of peak ops with a
n IO540.
>>>>>
>>>>> Continental (admittedly not a Lyc IO540), had a wonderful simulation /
presentation about how to safely run LOP. Their position was to stay under 6
5% power to avoid the "red Box".
>>>>>
>>>>> Lycoming seemed to think that LOP was was a high risk venture that mos
t mere mortals should avoid like the plague. They even has a 2000 monograph t
hat had a few veiled references to Gami.
>>>>>
>>>>> Mike Busch was very much in support of LOP ops in either brand C or L e
ngines. His view was physics doesnt't change with the brand of engine.
>>>>>
>>>>> So, given that we have now resolved how to properly prime lithium batt
eries, I would be interested in hearing about first hand LOP experiences. Ha
s anyone experienced problems with LOP. Lycoming seems to think that LOP req
uires more attention to detail than the average pilot can muster when things
busy. They also suggest that ROP at power settings that match LOP power yie
lds similar albeit somewhat higher fuel flows. Does actual experience bear t
his out?
>>>>>
>>>>> Any comments?
>>>>>
>>>>> Cheers
>>>>>
>>>>> Les
>>>>> Inquiring minds need to know!
>>>>>
>>>>> ============
>>>>> RV10-List Email Forum -
>>>>> http://www.matronics.com/Navigator?RV10-List =========
==== sp; - MATRONICS WEB FORUMS - ===========
== sp; - List Contribution Web Site - sp; -Matt Dral
le, List Admin. http://www.matronics.com/c============
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> get="_blank">http://www.matronics.com/Navigator?RV10-List
>>>> tp://forums.matronics.com
>>>> _blank">http://www.matronics.com/contribution
>>>>
>>>
>>>
>>>
>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>> List"">http://www.matronics.com/Navigator?RV10-List
>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>> //forums.matronics.com
>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>> ot;">http://www.matronics.com/contribution
>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>>
>>
>>
>> get="_blank">http://www.matronics.com/Navigator?RV10-List
>> tp://forums.matronics.com
>> _blank">http://www.matronics.com/contribution
>>
>
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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>
Message 15
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| Subject: | Re: Lean of Peak and other heresies |
The only way to determine power LOP is by the fuel flow calculation I
provided earlier. While higher compression does provide somewhat better
efficiency, it is offset by lower detonation margins. I don't know
whether WOT with stock compression would be less or equally efficient
than partial throttle with higher compression. I do know that partial
throttle does disrupt the airflow into the manifold. Whether that
offsets some of the efficiency gain would probably have to be determined
on a dyno or other instrumented setup.
I just prefer the keep it simple way of doing things, so that if
something fails, I can get replacement stock parts, and I don't have to
worry if I find myself somewhere that only 91 octane mogas is available.
All choices that we get to make as amateur builders. Only those that
make sense for our individual needs are the right ones.
Kelly
On 8/11/2014 8:56 PM, Don McDonald wrote:
> How about 9:5 compression? That's what I have, and I fly LOP
> everywhere. Lot's of hp, 3 blade prop... cruise at 1/2 throttle (at
> 10,500', instead of WOT providing 21.3 inches, I'm around 18.5") and
> between 2,000 and 2,100 rpm. I'm sure Kelley will tell us what % power
> that setting is. Before some of you say "he can't get 21.3" at 10,500,
> I only get 20.3".... you can if you have a 4" forward facing servo
> with cold air induction and an F1 Rocket scoop.
> With these settings we cruise fast enough (156kts), have a low fuel
> burn, and the engine temps and my wallet are very happy.
> Don Mc
>
> ------------------------------------------------------------------------
> *From:* Les Kearney <kearney@shaw.ca>
> *To:* "rv10-list@matronics.com" <rv10-list@matronics.com>
> *Sent:* Monday, August 11, 2014 10:21 PM
> *Subject:* Re: RV10-List: Lean of Peak and other heresies
>
> Hmmm
>
> Has anyone run LOP with 9:1 compression cylinders?
>
> For the IO540, is there a power setting analogous to the Brand C 65%
> power setting that eliminates the red box risk?
>
> Cheers
>
> Les
>
> Sent from my iPhone
>
> On Aug 11, 2014, at 8:53 PM, Kelly McMullen <apilot2@gmail.com
> <mailto:apilot2@gmail.com>> wrote:
>
>> Pascal has it right. Lycoming says you are too inattentive, too dumb
>> and basically incapable of operating lean of peak because a. their
>> engineers have never tried it
>> b. their engineers are too stupid to understand it
>> c. their lawyers perceive a little itty bitty risk that must be avoided
>> d. they wouldn't want to change from what they recommended 50 yrs ago.
>> I've operated my 200 hp Lycoming IO-360-A1A LOP for the past 12 yrs
>> or 700 hours without a problem. Prior to that it had some valve
>> sticking that probably caused overload on the cam lobes that resulted
>> in spalled cam lobes and lifters. It is stock 8.7:1 compression
>> requiring 100 octane minimum...closer to detonation margin than an
>> stock IO-540 260 hp at 8.5:1 compression.
>> The main thing is to understand that you have one reference point for
>> ROP (when the first cylinder peaks) and LOP (when the LAST cylinder
>> peaks). I normally run full throttle and 10-20 LOP anywhere above
>> 6000 ft (~24" MAP). Fuel consumption will be about 0.5 gph per
>> cylinder less than same power ROP.
>> 75% for IO-540=195hp = ~13gph LOP.
>> 65%=169hp=~11.3 gph
>> for normally aspirated engines between 8.5 and 8.7 to 1 compression
>> when LOP power=FF*15 (14.9 if you want that much precision)
>>
>>
>> On Mon, Aug 11, 2014 at 7:18 PM, Les Kearney <kearney@shaw.ca
>> <mailto:kearney@shaw.ca>> wrote:
>>
>> Hi Pascal
>>
>> Here is a link to the monograph I hot from Lycoming at KOSH.
>>
>> http://www.shamrockairservices.com/images/LEANING%20TECHNIQUES.pdf
>>
>> Cheers
>>
>> Les
>>
>> Sent from my iPhone
>>
>> On Aug 11, 2014, at 7:43 PM, "Pascal" <rv10flyer@live.com
>> <mailto:rv10flyer@live.com>> wrote:
>>
>>> Plainly put the lycoming rep was uneducated on the Lycoming stance:
>>> http://www.avweb.com/news/maint/182849-1.html?redirected=1
>>> Lie #7:
>>> Aggressive leaning results in burned valves and detonation.
>>> Fear of the red knob is one of the most pernicious areas of
>>> misinformation among general aviation pilots. Most pilots
>>> operate way too rich most of the time, and do so because of the
>>> mistaken belief that leaning will harm their engine. The result
>>> is usually trouble: fouled spark plugs, accelerated exhaust
>>> valve guide wear, and stuck exhaust valves.
>>> Lycoming engine Lycoming has long authorized leaning to peak EGT
>>> at any cruise setting up to 75% power. TCM authorizes leaning to
>>> peak EGT up to 65%, and its latest recommendations even endorse
>>> lean-of-peak operation for many big-bore engines, provided the
>>> engines will run smoothly when operated that lean.
>>> Contrary to popular belief, aggressive leaning doesn't cause
>>> burned valves. Most burned valves are the result of excessive
>>> valve guide wear or valve stem contamination.
>>> Aggressive leaning doesn't cause detonation, either. Most of our
>>> engines are incapable of detonation at cruise power settings,
>>> provided that we don't exceed CHT red-line or try to burn
>>> contaminated fuel. Furthermore, recent tests on Lycoming engines
>>> by ASTM revealed this fascinating result: detonation is most
>>> likely to occur at a mixture setting 11% richer than
>>> stoichiometric (i.e., substantially richer than peak EGT).
>>> Lean as aggressively as the book allows. For Lycomings, that
>>> means peak EGT at all cruise power settings to 75%. For
>>> Continentals, lean to peak EGT up to 65%, 50F rich of peak at
>>> 75%. For turbocharged engines, also limit TIT to 1600F.
>>> Lean during all ground operations except for engine start. It is
>>> particularly important to lean for taxi and runup. Since EGT is
>>> usually off-scale at idle power, the best method is to lean for
>>> peak RPM at idle.
>>> Read through Lycomings Key Operations- found on the lycoming
>>> site. Plenty about leaning at 75% and lower and even a chart
>>> that says they do not recommend LOP, but on the same page has:
>>> pg38
>>> 6. Leaning to best economy mixture.
>>> a. Set manifold pressure and RPM for the desired cruise power
>>> setting per the aircraft POH/AFM.
>>> b. Lean slowly in small steps, while monitoring instrumentation,
>>> to peak TIT or maximum allowable TIT, whichever occurs first
>>> <image[3].png>
>>> than on pg 39:
>>> Once cruise power has been set, leaning to best economy should
>>> be standard procedure as damage to the engine will not occur
>>> from leaning at cruise power settings.
>>> -----Original Message-----
>>> From: LES KEARNEY
>>> Sent: Monday, August 11, 2014 6:09 PM
>>> To: rv10-list@matronics.com <mailto:rv10-list@matronics.com>
>>> Subject: RV10-List: Lean of Peak and other heresies
>>> <mailto:kearney@shaw.ca>>
>>> Hi
>>> At KOSH I received some very conflicted info on lean of peak ops
>>> with an IO540.
>>> Continental (admittedly not a Lyc IO540), had a wonderful
>>> simulation / presentation about how to safely run LOP. Their
>>> position was to stay under 65% power to avoid the "red Box".
>>> Lycoming seemed to think that LOP was was a high risk venture
>>> that most mere mortals should avoid like the plague. They even
>>> has a 2000 monograph that had a few veiled references to Gami.
>>> Mike Busch was very much in support of LOP ops in either brand C
>>> or L engines. His view was physics doesnt't change with the
>>> brand of engine.
>>> So, given that we have now resolved how to properly prime
>>> lithium batteries, I would be interested in hearing about first
>>> hand LOP experiences. Has anyone experienced problems with LOP.
>>> Lycoming seems to think that LOP requires more attention to
>>> detail than the average pilot can muster when things busy. They
>>> also suggest that ROP at power settings that match LOP power
>>> yields similar albeit somewhat higher fuel flows. Does actual
>>> experience bear this out?
>>> Any comments?
>>> Cheers
>>> Les
>>> Inquiring minds need to know!
>>> ============
>>> RV10-List Email Forum -
>>> http://www.matronics.com/Navigator?RV10-List ============
>>> sp; - MATRONICS WEB FORUMS - ============= sp; - List
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>>
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| Subject: | Re: Lean of Peak and other heresies |
Hi Les,
Like I said, individual choices, individual opinions. Compression needs
are probably related to which primer you used......................
IIRC the -10 will climb over any rock in North America with a stock
engine. I know the service ceiling is higher than my 200 hp Mooney that
will do 18,800 for service ceiling. IIRC there aren't too many rocks in
Canada besides Mt. Logan that are in the upper teens.
Of course most of us ignore the advice that mods take time, money, more
time and more money.
On 8/11/2014 9:06 PM, Les Kearney wrote:
> Hi Kelly
>
> I am not too fussed about 100ll. As well, I plan to fly over the rocks
> to the west.
>
> Cheers
>
> Les
>
> Sent from my iPhone
>
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| Subject: | Want to fly and own an RV-10 |
Cheers
I have just joined the RV-10 list because I want to fly and own an
RV-10.
Have built and have eight years flying a 'RV-derivative' Rocket. Love
flying the Rocket, but "life changes"have caused me to want a
more-comfortable, larger aircraft.
Need some help:
1) wish to determine if RV-10 is fun to fly ( like the other RVs have
flown) -- welcome comments from you, but also want to fly in an RV-10
with someone in the Southwest, not too far from Los Angeles. Will pay
for expenses.
2) Am looking for a well-built and well maintained RV-10 to purchase.
Please respond with comments and/ or if you can help...
Thanks
Dave B
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