Today's Message Index:
----------------------
1. 03:38 AM - Re: ROP versus LOP...might be off-topic for some (Lynn Matteson)
2. 11:12 AM - Re: ROP versus LOP...might be off-topic for some (Noel Loveys)
3. 01:16 PM - Re: ROP versus LOP...might be off-topic for some (BobsV35B@aol.com)
4. 01:24 PM - Re: ROP versus LOP...might be off-topic for some (BobsV35B@aol.com)
5. 02:47 PM - ROP versus LOP... How to lean a bing (=?iso-8859-1?Q?J=E9rme_Delamare?=)
6. 03:22 PM - Re: ROP versus LOP... How to lean a bing (BobsV35B@aol.com)
7. 05:21 PM - Re: ROP versus LOP... How to lean a bing (Lynn Matteson)
8. 05:57 PM - Re: ROP versus LOP...might be off-topic for some (Lynn Matteson)
9. 07:09 PM - Re: ROP versus LOP... How to lean a bing (Richard Girard)
10. 07:53 PM - Re: ROP versus LOP...might be off-topic for some (BobsV35B@aol.com)
Message 1
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| Subject: | Re: ROP versus LOP...might be off-topic for some |
Exactly, Noel. In all the readings I've done over the last couple of
weeks, that is the MOST- often repeated caveat...."don't try LOP when
pulling power". The power will fall off even if in a cruise
situation, so this operating at "lean of peak EGT" is only for
cruising. I've read a lot about it in John Deakin's articles on
AVweb.com. I'm surprised that this has been around for so long, and I
hadn't heard about it until now. I only heard about it a few weeks
ago, and then did a search for "lean of peak" on google, and found
thousands of articles. Another warning is that we have all cylinders
monitored for EGT and CHT when trying to run LOP. And of course, the
engine has to be capable of mixture control. Mine wasn't until I
installed the Rotec TBI-40 with its mixture control. Stuck with a
Bing, I wasn't able to try this operation.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 742.8 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Aug 24, 2009, at 11:14 PM, Noel Loveys wrote:
> <noelloveys@yahoo.ca>
>
> Lynn:
>
> For what it's worth my training told me that LOP is ok as long as
> you are
> not drawing any power. If you are in a situation where power has
> to be
> pulled you are better off at ROP. If you are constantly running
> LOP keep a
> close eye on the top of your pistons.
>
> Noel
>
> -----Original Message-----
> From: owner-jabiruengine-list-server@matronics.com
> [mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of
> Lynn
> Matteson
> Sent: Saturday, August 15, 2009 3:45 PM
> To: jabiruengines@yahoogroups.com; kitfox-list@matronics.com;
> jabiruengine-list@matronics.com
> Subject: JabiruEngine-List: ROP versus LOP...might be off-topic for
> some
>
> <lynnmatt@jps.net>
>
> Over the last week, I've had some fun making some tests with my newly-
> installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
> device on my Jabiru engine. I don't know whether two of these units
> will work on a Rotax, so many of you might want to hit the delete key
> right now.
>
> For the most part, I was flying it LOP (lean-of-peak), but yesterday
> I made a flight and decided that I would try ROP (rich-of-peak). In
> flying LOP, the articles I've read say to keep the power requirements
> low, and LOP will work and you won't burn the engine down. I was
> amazed that this LOP thing even works at all, let alone work as well
> as I've found that it seems too....I guess I'm still a bit of a
> skeptic. After all, if going lean is a bad thing, how can going even
> leaner be a good thing? I won't argue whether or not it's a good or
> bad thing, and there are those of you that may not be able to do any
> leaning at all, as I was until I got this unit.
> Three days ago, I made two trips totaling 475 miles, using LOP
> settings, and yesterday I made a 310-mile trip, using ROP settings. I
> had flown the 475 miles leaning out the engine until peak EGT, then
> leaning more until the engine was obviously low on power, and I
> contentedly flew at this setting, watching the scenery crawl by.
> Yesterday I decided to actually GO somewhere, and never mind the fuel
> saving, I just wanted to get there, so I decided to try ROP.
> Here are the average numbers from those trips:
>
> LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
> miles per hour
> ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3 miles per
> hour
>
> Altitudes on all of these flight were anywhere from 3000' MSL (with a
> base of 1000') to 10,000 MSL, with throttle settings from 2600 rpm to
> 3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
> hour to 5.0 not including takeoffs, but including climbs.
>
> So you can see from these figures (admittedly a low number of
> samples) that it does pay to tweak the mixture, and even if flown
> LOP, the speed is not too bad.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 737.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
>
>
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| Subject: | ROP versus LOP...might be off-topic for some |
Increasing throttle under load
So basically what I was saying was the same thing as Continental and
Lycoming. Stay rich of peak when you need lots of power. Lean of Peak
should be reserved basically for long descents at lower throttle settings,
taxiing or possibly endurance flight.
When I was in flight school the school instructed me to always lean the
engine LOP except for takeoff which we used full throttle for a lot of the
training exercises that was ok but we cruised the C172 at close to 75%
throttle. On solo flights I always ran ROP except if I was doing a long
decent of say five minutes or more. Once in the landing circuit I always
went full rich to be ready to draw power for a go around.
Most of the carbs are set up to run the engine a little rich at idle to make
them easier to start. While warming up an engine or taxiing I usually
mixed LOP. Part of the checklist turning onto the runway was to mix full
rich. The field was on a plateau 400 ft msl.
A lot of the instructors and students didn't use the same fuel management on
the ground as I did and as far as I can see the paid for it fouled plugs.
On one occasion I saw the plane I was about to fly pull up to the fuel pumps
spewing a fair bit of soot from the exhaust. I called the AME ( Aircraft
Maintenance Engineer) lean the idle mixture a bit. For a week the engine
ran great but one student just couldn't get it started after a cold night so
they enrichened it again until we got warmer weather.
I'm not sure if the flight school wanted to keep me or kill me. Almost
every flight I would find snags in the plane. Low tires, crud build up on
the control hinges and spinner problems were all cleared in short order.
That may have been why they always scheduled me to fly at daybreak. The
plane wouldn't see and engineer until my next flight. I also noticed the
instructors would stick close to the other students during their walk around
but in my case they only checked the fuel caps were in place..
Noel
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of
BobsV35B@aol.com
Sent: Tuesday, August 25, 2009 1:08 AM
Subject: Re: JabiruEngine-List: ROP versus LOP...might be off-topic for some
Good Evening Noel,
Could you define what you mean by "pulling power".
Continental Motors generally suggests that lean side operations be
restricted to sixty-five percent of maximum rated power. Lycoming generally
uses a figure of seventy-five percent for the same purpose. Both
manufacturers have a considerable number of restrictions as to when and how
to run lean.
There are many text books that delve into lean side operations.
Curtiss Wright Corporation has given us about the most extensive guidance I
have ever seen as to the "How Too's" of large radial engines.
Advanced Pilot Seminars of Ada, Oklahoma, teach a course of engine
management which uses Continental, Lycoming and Curtiss Wright data to teach
what really is happening at various power settings.
At very high power settings, (above sixty-five to seventy-five percent of
maximum continuous horsepower)extra fuel is used by most aircraft engine
manufacturers to move the peak cylinder pressures to a point where adequate
cooling can be provided.
That data correlates well with data given by both Lycoming and Continental.
When does your training say that lean side operation is acceptable?
Happy Skies,
Old Bob
In a message dated 8/24/2009 10:18:24 P.M. Central Daylight Time,
noelloveys@yahoo.ca writes:
Lynn:
For what it's worth my training told me that LOP is ok as long as you are
not drawing any power. If you are in a situation where power has to be
pulled you are better off at ROP. If you are constantly running LOP keep a
close eye on the top of your pistons.
Noel
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Saturday, August 15, 2009 3:45 PM
jabiruengine-list@matronics.com
Subject: JabiruEngine-List: ROP versus LOP...might be off-topic for some
Over the last week, I've had some fun making some tests with my newly-
installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
device on my Jabiru engine. I don't know whether two of these units
will work on a Rotax, so many of you might want to hit the delete key
right now.
For the most part, I was flying it LOP (lean-of-peak), but yesterday
I made a flight and decided that I would try ROP (rich-of-peak). In
flying LOP, the articles I've read say to keep the power requirements
low, and LOP will work and you won't burn the engine down. I was
amazed that this LOP thing even works at all, let alone work as well
as I've found that it seems too....I guess I'm still a bit of a
skeptic. After all, if going lean is a bad thing, how can going even
leaner be a good thing? I won't argue whether or not it's a good or
bad thing, and there are those of you that may not be able to do any
leaning at all, as I was until I got this unit.
Three days ago, I made two trips totaling 475 miles, using LOP
settings, and yesterday I made a 310-mile trip, using ROP settings. I
had flown the 475 miles leaning out the engine until peak EGT, then
leaning more until the engine was obviously low on power, and I
contentedly flew at this setting, watching the scenery crawl by.
Yesterday I decided to actually GO somewhere, and never mind the fuel
saving, I just wanted to get there, so I decided to try ROP.
Here are the average numbers from those trips:
LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
miles per hour
ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3 miles per
hour
Altitudes on all of these flight were anywhere from 3000' MSL (with a
base of 1000') to 10,000 MSL, with throttle settings from 2600 rpm to
3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
hour to 5.0 not including takeoffs, but including climbs.
So you can see from these figures (admittedly a low number of
samples) that it does pay to tweak the mixture, and even if flown
LOP, the speed is not too bad.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 737.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: ================================================= Use utilities Day
================================================ - MATRONICS
WEB FORUMS ================================================ -
List Contribution Web Site sp;
==================================================
_____
Message 3
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| Subject: | Re: ROP versus LOP...might be off-topic for some |
Good Afternoon Noel,
Do you generally cruise above seventy-five percent power?
If so, ROP is probably best unless you have a supercharger. Whole 'nother
question.
Do you ever cruise above six thousand feet MSL?
If you do (with a normally aspirated engine) there is no way you could
damage the engine with the mixture control regardless of what you did with
it!
Personally, I find that the vast majority of my flying is done at power
settings where LOP is by FAR the better way to go.
Very few flight training operations have the time or the inclination to
teach proper engine operations for any regime other than the basic trainin
g
operation. It is also very rare that any training operation will have
instrumentation installed that will tell the pilot whether or not the fuel
distribution is good enough to allow Lean Side Operations.
Individual airplanes of the same model and same vintage often vary widely
as to fuel distribution. There are methods that can be used to determine
fuel balance, but it gets quite time consuming to do so. Without good
distribution, you can't take advantage of the lean side.
However, once we do have good distribution and lean side operations ARE
practical, the benefits are great.
That is the beauty of a course such as is available from the Advanced Pilo
t
Seminar folks. It teaches us first how to find out how the airplane we ar
e
flying works. It then tells us how to fix it if something is wrong.
As Lynn has told us, he was fortunate enough to read most of what John
Deakin has written on the subject.
There are a lot of Old Wives Tales that are taught beginning students
because there is not adequate time in the training syllabus to completely
cover
the issue.
If you include normal cross country flight as your definition of endurance
flight and you don't go cross country, I guess you have little use for Lea
n
Side operation, but I cannot imagine operating in any other way.
It does take training. There is no quick "cookie cutter" formula to tell
us
how to do it, but the benefits in longer engine life, cooler operations,
and cleaner engine operations are worth the effort all by themselves.
The lower fuel costs and greater range available are just icing on the
cake.
I never flew a piston engine airliner that was NOT operated in some form
of
lean side operation. For the short haul airplanes, it was "Auto Lean'.
For long haul, especially when we had the services of a flight engineer,
it
was manually leaned well beyond the point of Auto Lean.
We now have the benefit of excellent low cost engine instrumentation to
tell us what Lindbergh had to find out by lengthy bouts of experimentation
,
but the results have NOT changed since those days of long ago.
Leaner is Cooler and Leaner is Better!
I think Lynn is right on the true path to greater knowledge of how to
properly, safely, and efficiently, operate his engine.
Make any sense at all?
Happy Skies,
Old Bob
In a message dated 8/25/2009 1:12:49 P.M. Central Daylight Time,
noelloveys@yahoo.ca writes:
Increasing throttle under load
So basically what I was saying was the same thing as Continental and
Lycoming Stay rich of peak when you need lots of power. Lean
of Peak should
be reserved basically for long descents at lower throttle settings, taxii
ng
or possibly endurance flight.
When I was in flight school the school instructed me to always lean the
engine LOP except for takeoff which we used full throttle for a lot of
the
training exercises that was ok but we cruised the C172 at close to 75%
throttle. On solo flights I always ran ROP except if I was doing a long
decent
of say five minutes or more. Once in the landing circuit I always went
full rich to be ready to draw power for a go around.
Most of the carbs are set up to run the engine a little rich at idle to
make them easier to start. While warming up an engine or taxiing I usua
lly
mixed LOP. Part of the checklist turning onto the runway was to mix full
rich The field was on a plateau 400 ft msl.
A lot of the instructors and students didn=99t use the same fuel ma
nagement
on the ground as I did and as far as I can see the paid for it fouled
plugs. On one occasion I saw the plane I was about to fly pull up to the
fuel
pumps spewing a fair bit of soot from the exhaust. I called the AME (
Aircraft Maintenance Engineer) lean the idle mixture a bit. For a week
the
engine ran great but one student just couldn=99t get it started aft
er a cold
night so they enrichened it again until we got warmer weather.
I=99m not sure if the flight school wanted to keep me or kill me.
Almost
every flight I would find snags in the plane. Low tires, crud build up
on
the control hinges and spinner problems were all cleared in short order.
That may have been why they always scheduled me to fly at daybreak
The plane
wouldn=99t see and engineer until my next flight. I also noticed
the
instructors would stick close to the other students during their walk arou
nd but
in my case they only checked the fuel caps were in place.
Noel
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of BobsV3
5B@aol.com
Sent: Tuesday, August 25, 2009 1:08 AM
Subject: Re: JabiruEngine-List: ROP versus LOP...might be off-topic for
some
Good Evening Noel,
Could you define what you mean by "pulling power".
Continental Motors generally suggests that lean side operations be
restricted to sixty-five percent of maximum rated power. Lycoming general
ly uses a
figure of seventy-five percent for the same purpose. Both manufacturers
have a considerable number of restrictions as to when and how to run lea
n.
There are many text books that delve into lean side operations.
Curtiss Wright Corporation has given us about the most extensive guidance
I have ever seen as to the "How Too's" of large radial engines.
Advanced Pilot Seminars of Ada, Oklahoma, teach a course of engine
management which uses Continental, Lycoming and Curtiss Wright data to te
ach what
really is happening at various power settings.
At very high power settings, (above sixty-five to seventy-five percent of
maximum continuous horsepower)extra fuel is used by most aircraft engine
manufacturers to move the peak cylinder pressures to a point where adequa
te
cooling can be provided.
That data correlates well with data given by both Lycoming and
Continental.
When does your training say that lean side operation is acceptable?
Happy Skies,
Old Bob
In a message dated 8/24/2009 10:18:24 P.M. Central Daylight Time,
noelloveys@yahoo.ca writes:
--> JabiruEngine-List message posted by: "Noel Loveys"
<noelloveys@yahoo.ca>
Lynn:
For what it's worth my training told me that LOP is ok as long as you are
not drawing any power. If you are in a situation where power has to be
pulled you are better off at ROP. If you are constantly running LOP keep
a
close eye on the top of your pistons.
Noel
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Saturday, August 15, 2009 3:45 PM
jabiruengine-list@matronics.com
Subject: JabiruEngine-List: ROP versus LOP...might be off-topic for some
Over the last week, I've had some fun making some tests with my newly-
installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
device on my Jabiru engine. I don't know whether two of these units
will work on a Rotax, so many of you might want to hit the delete key
right now.
For the most part, I was flying it LOP (lean-of-peak), but yesterday
I made a flight and decided that I would try ROP (rich-of-peak). In
flying LOP, the articles I've read say to keep the power requirements
low, and LOP will work and you won't burn the engine down. I was
amazed that this LOP thing even works at all, let alone work as well
as I've found that it seems too....I guess I'm still a bit of a
skeptic. After all, if going lean is a bad thing, how can going even
leaner be a good thing? I won't argue whether or not it's a good or
bad thing, and there are those of you that may not be able to do any
leaning at all, as I was until I got this unit.
Three days ago, I made two trips totaling 475 miles, using LOP
settings, and yesterday I made a 310-mile trip, using ROP settings. I
had flown the 475 miles leaning out the engine until peak EGT, then
leaning more until the engine was obviously low on power, and I
contentedly flew at this setting, watching the scenery crawl by.
Yesterday I decided to actually GO somewhere, and never mind the fuel
saving, I just wanted to get there, so I decided to try ROP.
Here are the average numbers from those trips:
LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
miles per hour
ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3 miles pe
r
hour
Altitudes on all of these flight were anywhere from 3000' MSL (with a
base of 1000') to 10,000 MSL, with throttle settings from 2600 rpm to
3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
hour to 5.0 not including takeoffs, but including climbs.
So you can see from these figures (admittedly a low number of
samples) that it does pay to tweak the mixture, and even if flown
LOP, the speed is not too bad.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 737.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: ======================
== Use utilities Day ================
=======
- MATRONICS WEB FORUMS =============
========== - List
Contribution Web Site sp;
____________________________________
http://www.matronics.com/Navigator?JabiruEngine-List
http://forums.matronics.com
http://www.matronics.com/contribution
========================
============
(http://www.matronics.com/Navigator?JabiruEngine-List)
========================
============
========================
============
(http://www.matronics.com/contribution)
========================
============
Message 4
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| Subject: | Re: ROP versus LOP...might be off-topic for some |
Good Afternoon Noel,
Do you generally cruise above seventy-five percent power?
If so, ROP is probably best unless you have a supercharger. Whole 'nother
question.
Do you ever cruise above six thousand feet MSL?
If you do (with a normally aspirated engine) there is no way you could
damage the engine with the mixture control regardless of what you did with
it!
Personally, I find that the vast majority of my flying is done at power
settings where LOP is by FAR the better way to go.
Very few flight training operations have the time or the inclination to
teach proper engine operations for any regime other than the basic trainin
g
operation. It is also very rare that any training operation will have
instrumentation installed that will tell the pilot whether or not the fuel
distribution is good enough to allow Lean Side Operations.
Individual airplanes of the same model and same vintage often vary widely
as to fuel distribution. There are methods that can be used to determine
fuel balance, but it gets quite time consuming to do so. Without good
distribution, you can't take advantage of the lean side.
However, once we do have good distribution and lean side operations ARE
practical, the benefits are great.
That is the beauty of a course such as is available from the Advanced Pilo
t
Seminar folks. It teaches us first how to find out how the airplane we ar
e
flying works. It then tells us how to fix it if something is wrong.
As Lynn has told us, he was fortunate enough to read most of what John
Deakin has written on the subject.
There are a lot of Old Wives Tales that are taught beginning students
because there is not adequate time in the training syllabus to completely
cover
the issue.
If you include normal cross country flight as your definition of endurance
flight and you don't go cross country, I guess you have little use for Lea
n
Side operation, but I cannot imagine operating in any other way.
It does take training. There is no quick "cookie cutter" formula to tell
us
how to do it, but the benefits in longer engine life, cooler operations,
and cleaner engine operations are worth the effort all by themselves.
The lower fuel costs and greater range available are just icing on the
cake.
I never flew a piston engine airliner that was NOT operated in some form
of
lean side operation. For the short haul airplanes, it was "Auto Lean'.
For long haul, especially when we had the services of a flight engineer,
it
was manually leaned well beyond the point of Auto Lean.
We now have the benefit of excellent low cost engine instrumentation to
tell us what Lindbergh had to find out by lengthy bouts of experimentation
,
but the results have NOT changed since those days of long ago.
Leaner is Cooler and Leaner is Better!
I think Lynn is right on the true path to greater knowledge of how to
properly, safely, and efficiently, operate his engine.
Make any sense at all?
Happy Skies,
Old Bob
In a message dated 8/25/2009 1:12:49 P.M. Central Daylight Time,
noelloveys@yahoo.ca writes:
Increasing throttle under load
So basically what I was saying was the same thing as Continental and
Lycoming Stay rich of peak when you need lots of power. Lean
of Peak should
be reserved basically for long descents at lower throttle settings, taxii
ng
or possibly endurance flight.
When I was in flight school the school instructed me to always lean the
engine LOP except for takeoff which we used full throttle for a lot of
the
training exercises that was ok but we cruised the C172 at close to 75%
throttle. On solo flights I always ran ROP except if I was doing a long
decent
of say five minutes or more. Once in the landing circuit I always went
full rich to be ready to draw power for a go around.
Most of the carbs are set up to run the engine a little rich at idle to
make them easier to start. While warming up an engine or taxiing I usua
lly
mixed LOP. Part of the checklist turning onto the runway was to mix full
rich The field was on a plateau 400 ft msl.
A lot of the instructors and students didn=99t use the same fuel ma
nagement
on the ground as I did and as far as I can see the paid for it fouled
plugs. On one occasion I saw the plane I was about to fly pull up to the
fuel
pumps spewing a fair bit of soot from the exhaust. I called the AME (
Aircraft Maintenance Engineer) lean the idle mixture a bit. For a week
the
engine ran great but one student just couldn=99t get it started aft
er a cold
night so they enrichened it again until we got warmer weather.
I=99m not sure if the flight school wanted to keep me or kill me.
Almost
every flight I would find snags in the plane. Low tires, crud build up
on
the control hinges and spinner problems were all cleared in short order.
That may have been why they always scheduled me to fly at daybreak
The plane
wouldn=99t see and engineer until my next flight. I also noticed
the
instructors would stick close to the other students during their walk arou
nd but
in my case they only checked the fuel caps were in place.
Noel
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of BobsV3
5B@aol.com
Sent: Tuesday, August 25, 2009 1:08 AM
Subject: Re: JabiruEngine-List: ROP versus LOP...might be off-topic for
some
Good Evening Noel,
Could you define what you mean by "pulling power".
Continental Motors generally suggests that lean side operations be
restricted to sixty-five percent of maximum rated power. Lycoming general
ly uses a
figure of seventy-five percent for the same purpose. Both manufacturers
have a considerable number of restrictions as to when and how to run lea
n.
There are many text books that delve into lean side operations.
Curtiss Wright Corporation has given us about the most extensive guidance
I have ever seen as to the "How Too's" of large radial engines.
Advanced Pilot Seminars of Ada, Oklahoma, teach a course of engine
management which uses Continental, Lycoming and Curtiss Wright data to te
ach what
really is happening at various power settings.
At very high power settings, (above sixty-five to seventy-five percent of
maximum continuous horsepower)extra fuel is used by most aircraft engine
manufacturers to move the peak cylinder pressures to a point where adequa
te
cooling can be provided.
That data correlates well with data given by both Lycoming and
Continental.
When does your training say that lean side operation is acceptable?
Happy Skies,
Old Bob
In a message dated 8/24/2009 10:18:24 P.M. Central Daylight Time,
noelloveys@yahoo.ca writes:
--> JabiruEngine-List message posted by: "Noel Loveys"
<noelloveys@yahoo.ca>
Lynn:
For what it's worth my training told me that LOP is ok as long as you are
not drawing any power. If you are in a situation where power has to be
pulled you are better off at ROP. If you are constantly running LOP keep
a
close eye on the top of your pistons.
Noel
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Saturday, August 15, 2009 3:45 PM
jabiruengine-list@matronics.com
Subject: JabiruEngine-List: ROP versus LOP...might be off-topic for some
Over the last week, I've had some fun making some tests with my newly-
installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
device on my Jabiru engine. I don't know whether two of these units
will work on a Rotax, so many of you might want to hit the delete key
right now.
For the most part, I was flying it LOP (lean-of-peak), but yesterday
I made a flight and decided that I would try ROP (rich-of-peak). In
flying LOP, the articles I've read say to keep the power requirements
low, and LOP will work and you won't burn the engine down. I was
amazed that this LOP thing even works at all, let alone work as well
as I've found that it seems too....I guess I'm still a bit of a
skeptic. After all, if going lean is a bad thing, how can going even
leaner be a good thing? I won't argue whether or not it's a good or
bad thing, and there are those of you that may not be able to do any
leaning at all, as I was until I got this unit.
Three days ago, I made two trips totaling 475 miles, using LOP
settings, and yesterday I made a 310-mile trip, using ROP settings. I
had flown the 475 miles leaning out the engine until peak EGT, then
leaning more until the engine was obviously low on power, and I
contentedly flew at this setting, watching the scenery crawl by.
Yesterday I decided to actually GO somewhere, and never mind the fuel
saving, I just wanted to get there, so I decided to try ROP.
Here are the average numbers from those trips:
LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
miles per hour
ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3 miles pe
r
hour
Altitudes on all of these flight were anywhere from 3000' MSL (with a
base of 1000') to 10,000 MSL, with throttle settings from 2600 rpm to
3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
hour to 5.0 not including takeoffs, but including climbs.
So you can see from these figures (admittedly a low number of
samples) that it does pay to tweak the mixture, and even if flown
LOP, the speed is not too bad.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 737.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
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| Subject: | ROP versus LOP... How to lean a bing |
<lynnmatt@jps.net>
.../ Mine wasn't until I
installed the Rotec TBI-40 with its mixture control. Stuck with a
Bing, I wasn't able to try this operation/...
Hi Lynn,
It's quite easy to lean a bing. You just have to create a low pressure
in
the fuel bowl. The lower pressure you have, the more you lean.
Some people use the engine low pressure. I think HACman use this method
:
http://www.greenskyadventures.com/bing/4strokePG2.htm
Other people use an homemade air pump. The same kind of pump that you
can
find in a vacuum cleaner. This pump is located between the air box and
the
fuel bowl. With this method you can have an electric control of the
mixture
(partial vacuum depends on rpm). It's very safe because you just have to
switch off the vacuum pump and you run a "normal bing".
How simple is it ? (see picture)
DSC02431.JPG
This system has been designed by Michel Colomban. Michel Colomban is the
designer of the Cricri
(http://flight.cz/cricri/english/cri-cri-photos-pictures-cameron.php)
and
other airplanes like Bambi, MCR and Luciole.
With this system you can obtain a leaner mixture but not a richer one.
So if
you want to lean a bing, you need to apply JSB 18 in order to have a
rich
mixture in =93normal=94 operation.
J=E9rme
Jabiru #3144, MCR, Sensenich Carbon
Message 6
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| Subject: | Re: ROP versus LOP... How to lean a bing |
Good Evening Jerome,
Pretty cool!
More than one way to skin that cat.
Happy Skies,
Old Bob
In a message dated 8/25/2009 4:47:54 P.M. Central Daylight Time,
jeromedelamare@free.fr writes:
--> JabiruEngine-List message posted by: Lynn Matteson <lynnmatt@jps.net>
.../ Mine wasn't until I
installed the Rotec TBI-40 with its mixture control. Stuck with a
Bing, I wasn't able to try this operation/...
Hi Lynn,
It's quite easy to lean a bing. You just have to create a low pressure in
the fuel bowl. The lower pressure you have, the more you lean.
Some people use the engine low pressure. I think HACman use this method
:
_http://www.greenskyadventures.com/bing/4strokePG2.htm_
(http://www.greenskyadventures.com/bing/4strokePG2.htm)
Other people use an homemade air pump. The same kind of pump that you can
find in a vacuum cleaner. This pump is located between the air box and th
e
fuel bowl. With this method you can have an electric control of the
mixture (partial vacuum depends on rpm). It's very safe because you just
have to
switch off the vacuum pump and you run a "normal bing".
How simple is it ? (see picture)
This system has been designed by Michel Colomban. Michel Colomban is the
designer of the Cricri
(_http://flight.cz/cricri/english/cri-cri-photos-pictures-cameron.php_
(http://flight.cz/cricri/english/cri-cri-photos-pictures-cameron.php) )
and other airplanes like Bambi, MCR and Luciole.
With this system you can obtain a leaner mixture but not a richer one. So
if you want to lean a bing, you need to apply JSB 18 in order to have a
rich mixture in =9Cnormal=9D operation.
J=C3=A9r=C3=B4me
Jabiru #3144, MCR, Sensenich Carbon
Message 7
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| Subject: | Re: ROP versus LOP... How to lean a bing |
Hi Jerome-
If I understand this system correctly, you are putting a vacuum (low
pressure) on the float bowl, so the engine is fighting against this
vacuum to get its fair share of fuel, right? So it goes lean if you
put enough vacuum on the float bowl?
Somebody local told me about his leaning device, and it sounded
pretty much the same. I think he used the vacuum from the engine
going through a needle valve to control the vacuum, if I understood
him correctly.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 744.1 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Aug 25, 2009, at 5:28 PM, Jrme Delamare wrote:
> <lynnmatt@jps.net>
>
> .../ Mine wasn't until I
>
> installed the Rotec TBI-40 with its mixture control. Stuck with a
>
> Bing, I wasn't able to try this operation/...
>
>
> Hi Lynn,
>
>
> It's quite easy to lean a bing. You just have to create a low
> pressure in the fuel bowl. The lower pressure you have, the more
> you lean.
>
> Some people use the engine low pressure. I think HACman use this
> method :
>
> http://www.greenskyadventures.com/bing/4strokePG2.htm
>
>
> Other people use an homemade air pump. The same kind of pump that
> you can find in a vacuum cleaner. This pump is located between the
> air box and the fuel bowl. With this method you can have an
> electric control of the mixture (partial vacuum depends on rpm).
> It's very safe because you just have to switch off the vacuum pump
> and you run a "normal bing".
>
>
> How simple is it ? (see picture)
>
>
> This system has been designed by Michel Colomban. Michel Colomban
> is the designer of the Cricri (http://flight.cz/cricri/english/cri-
> cri-photos-pictures-cameron.php) and other airplanes like Bambi,
> MCR and Luciole.
>
>
> With this system you can obtain a leaner mixture but not a richer
> one. So if you want to lean a bing, you need to apply JSB 18 in
> order to have a rich mixture in normal operation.
>
>
> Jrme
>
>
> Jabiru #3144, MCR, Sensenich Carbon
>
>
Message 8
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| Subject: | Re: ROP versus LOP...might be off-topic for some |
Right now I'm testing the benefits of having done some hogging out of
the inside of the intake manifold. I also made a nylon washer-like
device that filled the gap between the rubber coupling and the Jabiru
adapter snout (my terminology...they may have a better name for it)
that bolts to the intake manifold. This device also takes out the
"stepping" in diametrical differences between the TBI and the coupler
and the snout.
In looking through the intake manifold, I could see that the front
cylinders appeared to be starving for air flow, so I did a little
"porting" to allow them to breathe better. Initial flights show that
I didn't hurt performance any, but some more flying will tell if I
did any good. I can say that initially, at least, the cylinders all
seem to peak at the same time...same fuel flow (3.1 gph).....although
still not at the same EGT. And I understand that getting the same EGT
is not critical between cylinders. I need to run the GAMI Lean Test
again to be sure, but initially I think I've got the EGT's peaking
Here are some pictures I took during the hogging out operation. The
first shows the view through the stock intake manifold, rear to
front. The second shows that the lower half of the manifold has been
cut, taking out some of the web that I felt was interfering with the
air flow to cyls. number 1&2...the front ones. The last picture shows
the almost finished job. You can see that there is more of the front
openings (where the intake tubes are inserted) visible, and that the
air should flow around the splitter/divider better. The factory had
apparently done some tests with shaping the splitter, and found that
its shape was the best they could do. I was even thinking of making
the splitter sort of hour-glass shaped, but decided to leave well
enough alone for the present time. Gotta save some fun for another
day. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 744.1 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Aug 25, 2009, at 4:10 PM, BobsV35B@aol.com wrote:
>
> Leaner is Cooler and Leaner is Better!
>
> I think Lynn is right on the true path to greater knowledge of how
> to properly, safely, and efficiently, operate his engine.
>
> Make any sense at all?
>
> Happy Skies,
>
> Old Bob
Message 9
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|
| Subject: | Re: ROP versus LOP... How to lean a bing |
Lynn, One of the guys on the Kolb list has been experimenting with mixture
control in the way you describe. Seems to work.
Rick Girard
On Tue, Aug 25, 2009 at 7:19 PM, Lynn Matteson <lynnmatt@jps.net> wrote:
>
> Hi Jerome-
> If I understand this system correctly, you are putting a vacuum (low
> pressure) on the float bowl, so the engine is fighting against this vacuu
m
> to get its fair share of fuel, right? So it goes lean if you put enough
> vacuum on the float bowl?
> Somebody local told me about his leaning device, and it sounded pretty mu
ch
> the same. I think he used the vacuum from the engine going through a need
le
> valve to control the vacuum, if I understood him correctly.
>
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 744.1 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
>
>
> On Aug 25, 2009, at 5:28 PM, J=E9rme Delamare wrote:
>
>
>>
>> .../ Mine wasn't until I
>>
>> installed the Rotec TBI-40 with its mixture control. Stuck with a
>>
>> Bing, I wasn't able to try this operation/...
>>
>>
>>
>> Hi Lynn,
>>
>>
>>
>> It's quite easy to lean a bing. You just have to create a low pressure i
n
>> the fuel bowl. The lower pressure you have, the more you lean.
>>
>> Some people use the engine low pressure. I think HACman use this method
:
>>
>> http://www.greenskyadventures.com/bing/4strokePG2.htm
>>
>>
>>
>> Other people use an homemade air pump. The same kind of pump that you ca
n
>> find in a vacuum cleaner. This pump is located between the air box and t
he
>> fuel bowl. With this method you can have an electric control of the mix
ture
>> (partial vacuum depends on rpm). It's very safe because you just have to
>> switch off the vacuum pump and you run a "normal bing".
>>
>>
>>
>> How simple is it ? (see picture)
>>
>>
>>
>> This system has been designed by Michel Colomban. Michel Colomban is the
>> designer of the Cricri (http://flight.cz/cricri/english/cri-cri-photos-p
ictures-cameron.php)
>> and other airplanes like Bambi, MCR and Luciole.
>>
>>
>>
>> With this system you can obtain a leaner mixture but not a richer one. S
o
>> if you want to lean a bing, you need to apply JSB 18 in order to have a
rich
>> mixture in =93normal=94 operation.
>>
>>
>>
>> J=E9rme
>>
>>
>>
>> Jabiru #3144, MCR, Sensenich Carbon
>>
>>
>>
>>
>>
>>
>>
>
>
===========
===========
===========
===========
>
>
Message 10
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| Subject: | Re: ROP versus LOP...might be off-topic for some |
Good Evening Lynn,
You are doing great!
It is true that the actual EGT temperature is immaterial. All that counts
is that all cylinders reach their peak EGT at the same fuel flow. One tenth
of a gallon is probably as good at is going to get. Maximum power will be
developed if each cylinder gets the same maximum amount of air. Sounds like
you are doing what it might take to get the maximum amount of air into each
cylinder.
Thanks for the update.
Happy Skies,
Old Bob
In a message dated 8/25/2009 7:58:00 P.M. Central Daylight Time,
lynnmatt@jps.net writes:
Right now I'm testing the benefits of having done some hogging out of
the inside of the intake manifold. I also made a nylon washer-like
device that filled the gap between the rubber coupling and the Jabiru
adapter snout (my terminology...they may have a better name for it)
that bolts to the intake manifold. This device also takes out the
"stepping" in diametrical differences between the TBI and the coupler
and the snout.
In looking through the intake manifold, I could see that the front
cylinders appeared to be starving for air flow, so I did a little
"porting" to allow them to breathe better. Initial flights show that
I didn't hurt performance any, but some more flying will tell if I
did any good. I can say that initially, at least, the cylinders all
seem to peak at the same time...same fuel flow (3.1 gph).....although
still not at the same EGT. And I understand that getting the same EGT
is not critical between cylinders. I need to run the GAMI Lean Test
again to be sure, but initially I think I've got the EGT's peaking
Here are some pictures I took during the hogging out operation. The
first shows the view through the stock intake manifold, rear to
front. The second shows that the lower half of the manifold has been
cut, taking out some of the web that I felt was interfering with the
air flow to cyls. number 1&2...the front ones. The last picture shows
the almost finished job. You can see that there is more of the front
openings (where the intake tubes are inserted) visible, and that the
air should flow around the splitter/divider better. The factory had
apparently done some tests with shaping the splitter, and found that
its shape was the best they could do. I was even thinking of making
the splitter sort of hour-glass shaped, but decided to leave well
enough alone for the present time. Gotta save some fun for another
day. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 744.1 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Aug 25, 2009, at 4:10 PM, BobsV35B@aol.com wrote:
>
> Leaner is Cooler and Leaner is Better!
>
> I think Lynn is right on the true path to greater knowledge of how
> to properly, safely, and efficiently, operate his engine.
>
> Make any sense at all?
>
> Happy Skies,
>
> Old Bob
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