 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
shempdowling2(at)earthlin
Guest
|
 Posted: Sat Aug 05, 2006 9:30 am Post subject: Leaning on ground? |
 |
|
So whats a good technique for leaning on the ground.
Shemp/Jeff Dowling
RV-6A, N915JD
295 hours
Chicago/Louisville
---
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
 |
pitts_pilot(at)bellsouth.
Guest
|
| Posted: Sat Aug 05, 2006 9:40 am Post subject: Leaning on ground? |
|
|
Jeff Dowling wrote:
| Quote: |
<shempdowling2(at)earthlink.net>
So whats a good technique for leaning on the ground.
|
Lean until it burps and then richen it up just a little till it runs
smooth. Even if you have an EGT gauge, the 'by feel' method will be
close to peak EGT.
Linn
do not archive
[quote]
Shemp/Jeff Dowling
RV-6A, N915JD
295 hours
Chicago/Louisville
---
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
khorton01(at)rogers.com
Guest
|
| Posted: Sat Aug 05, 2006 10:31 am Post subject: Leaning on ground? |
|
|
Make sure to lean it far enough so that it will stumble if you go to
high power. That way you can't inadvertently try to take off with
the mixture leaned, which could trigger detonation (low altitude take
off is assumed here). If you lean it as Linn suggests, you will be
fine, as the engine will definitely be running very poorly if you try
to take off with the mixture that far back.
Kevin Horton
On 5 Aug 2006, at 13:40, linn Walters wrote:
[quote]
<pitts_pilot(at)bellsouth.net>
Jeff Dowling wrote:
>
> <shempdowling2(at)earthlink.net>
>
> So whats a good technique for leaning on the ground.
Lean until it burps and then richen it up just a little till it
runs smooth. Even if you have an EGT gauge, the 'by feel' method
will be close to peak EGT.
Linn
do not archive
> Shemp/Jeff Dowling
> RV-6A, N915JD
> 295 hours
> Chicago/Louisville
>
> ---
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
Mark Sletten
Joined: 10 Jan 2006
Posts: 43
Location: St. Jacob, IL (Near St. Louis, MO)
|
| Posted: Sun Aug 06, 2006 5:17 am Post subject: Leaning on ground? |
|
|
Shemp,
Leaning your engine on the ground will greatly reduce the lead deposits on
your spark plugs. The anti-lead agent incorporated in AvGas doesn't activate
until things get hot - generally around 1800 RPM. Anytime you operate the
engine rich below that heat threshold you will be depositing lead on the
plugs.
Here's a good way to ground lean (Lycoming recommended):
Most people taxi with the RPM near idle; there's plenty of thrust to keep
rolling. You do, however, need a little more than that to get things
rolling, so you need to find the lowest RPM at which the aircraft starts to
move.
1. Taxi to a level area and close the throttle to idle.
2. Slowly advance the throttle with your feet off the brakes until the
aircraft starts to roll; note the RPM.
3. Stop.
4. Set the throttle to the RPM noted before (usually around 1200).
5. Lean the mixture until the RPM starts to drop off.
That's it! Set aside your fears of taking off with the mixture too lean -
your engine with falter and die if you advance the throttle beyond 1200 RPM
(or wherever you set the mixture). Similarly, have no fear of "burning up"
your engine due to an over-lean condition - you cannot over-lean the engine
at power settings below 75%.
If you don't want to go through the whole level ground thing (or if your
airplane starts rolling with the RPM at idle), just use 1200 RPM - it's
usually enough to get you started rolling unless you're pointed up a steep
hill. If you find you need a little more RPM to get started (grass, steep
hill, nose gear sharply turned, all of the above!) just push in the mixture
until you get started, then go back to your lean setting at 1200 RPM.
The first couple of times through the procedure will take some time; after
that it becomes second nature. You'll find yourself ground leading after
landing (as soon as you turn off the runway, of course) while taxiing to
parking.
A final note, do a 20 second run-up (at least 1800 RPM) prior to every
engine shut down. This will activate the anti-leading agent in the fuel
further reducing lead deposits. I run up to 1800 RPM, time for 20 seconds,
quickly back to 1200 RPM, then immediately pull the mixture to kill the
engine. If you don't touch the throttle, the next time you start the engine
it will already be at 1200 RPM - ready for setting the mixture to ground
lean.
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
_________________
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com |
|
| Back to top |
|
|
FLYaDIVE(at)aol.com
Guest
|
| Posted: Mon Aug 07, 2006 6:32 pm Post subject: Leaning on ground? |
|
|
In a message dated 8/6/06 9:19:38 AM Eastern Daylight Time,
marknlisa(at)hometel.com writes:
| Quote: | A final note, do a 20 second run-up (at least 1800 RPM) prior to every
engine shut down. This will activate the anti-leading agent in the fuel
further reducing lead deposits. I run up to 1800 RPM, time for 20 seconds,
quickly back to 1200 RPM, then immediately pull the mixture to kill the
engine. If you don't touch the throttle, the next time you start the engine
it will already be at 1200 RPM - ready for setting the mixture to ground
lean.
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
====================================
|
Mark:
I have seen this lean at shut down procedure written up by Lycoming. I have
great reservations about this procedure.
1 - Consider you just did an hour flight or maybe even a half hour flight.
Weren't you leaning during that flight? So why should you have to do it again?
2 - You just did this this leaning procedure before you took off to remove
the lead deposits. I would then ask two questions here:
a> Why not just do this procedure BEFORE you take off. Why would you have to
do it AGAIN after you land? Or;
b> If you did it after you land why would you have to do it again BEFORE you
take off? Confusing ain't it?
3 - You just did your flight, at least durring the flight even with leaning
you had a large volume of air moving through your cowling, helping things to
cool off. So, why would you sit on the ground heat the engine, then shut down
just to saturate the engine and the area under the cowl with heat?
Sounds like Lycoming has an ulterior motive for doing this procedure.
4 - What does heat saturation do? Well, it dries out hoses, wires, ty-wraps,
anti-chafe material ... add to the list as you see fit.
But, here is one area I noticed heat failure ... The plastic coupling on the
Vacuum Pump. Mine failed after 1935 Hours. Close inspection under
magnification revealed heat cracks. I also opened up the pump only to find PERFECTLY
GOOD insides. Probably would have gone for an additional 1935 Hours. Guess
where I'm putting a small blast tube? First guess doesn't count.
So, personally, I do not see any advantage in this procedure.
YMMV, yet there just seems to be holes in the procedure.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
pitts_pilot(at)bellsouth.
Guest
|
| Posted: Mon Aug 07, 2006 7:08 pm Post subject: Leaning on ground? |
|
|
Hi Barry! The Lycoming 'leaning/lead removing process' is done just before takeoff and just before shutdown because it supposes that you were taxiing around with the engine just above idle power. Low power operations do not get the cylinder temps up so the natural lead scavenging process can occur. Of course, if you leaned on the ground that violates Lycomings "8500' 75% power" rule so they can't support that. Mark could lessen the low power lead fouling problem by aggressive leaning on the ground or switch to an unleaded fuel.
Linn
do not archive
FLYaDIVE(at)aol.com (FLYaDIVE(at)aol.com) wrote:
| Quote: | | Quote: | --> RV-List message posted by: FLYaDIVE(at)aol.com (FLYaDIVE(at)aol.com)
In a message dated 8/6/06 9:19:38 AM Eastern Daylight Time,
marknlisa(at)hometel.com (marknlisa(at)hometel.com) writes:
| Quote: | A final note, do a 20 second run-up (at least 1800 RPM) prior to every
engine shut down. This will activate the anti-leading agent in the fuel
further reducing lead deposits. I run up to 1800 RPM, time for 20 seconds,
quickly back to 1200 RPM, then immediately pull the mixture to kill the
engine. If you don't touch the throttle, the next time you start the engine
it will already be at 1200 RPM - ready for setting the mixture to ground
lean.
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
|
====================================
Mark:
I have seen this lean at shut down procedure written up by Lycoming. I have
great reservations about this procedure.
1 - Consider you just did an hour flight or maybe even a half hour flight.
Weren't you leaning during that flight? So why should you have to do it again?
2 - You just did this this leaning procedure before you took off to remove
the lead deposits. I would then ask two questions here:
a> Why not just do this procedure BEFORE you take off. Why would you have to
do it AGAIN after you land? Or;
b> If you did it after you land why would you have to do it again BEFORE you
take off? Confusing ain't it?
3 - You just did your flight, at least durring the flight even with leaning
you had a large volume of air moving through your cowling, helping things to
cool off. So, why would you sit on the ground heat the engine, then shut down
just to saturate the engine and the area under the cowl with heat?
Sounds like Lycoming has an ulterior motive for doing this procedure.
4 - What does heat saturation do? Well, it dries out hoses, wires, ty-wraps,
anti-chafe material ... add to the list as you see fit.
But, here is one area I noticed heat failure ... The plastic coupling on the
Vacuum Pump. Mine failed after 1935 Hours. Close inspection under
magnification revealed heat cracks. I also opened up the pump only to find PERFECTLY
GOOD insides. Probably would have gone for an additional 1935 Hours. Guess
where I'm putting a small blast tube? First guess doesn't count.
So, personally, I do not see any advantage in this procedure.
YMMV, yet there just seems to be holes in the procedure.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
|
|
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
FLYaDIVE(at)aol.com
Guest
|
| Posted: Tue Aug 08, 2006 2:20 am Post subject: Leaning on ground? |
|
|
In a message dated 8/7/06 11:11:12 PM Eastern Daylight Time,
pitts_pilot(at)bellsouth.net writes:
| Quote: | Hi Barry! The Lycoming 'leaning/lead removing process' is done just
before takeoff and just before shutdown because it supposes that you
were taxiing around with the engine just above idle power. Low power
operations do not get the cylinder temps up so the natural lead
scavenging process can occur. Of course, if you leaned on the ground
that violates Lycomings "8500' 75% power" rule so they can't support
that. Mark could lessen the low power lead fouling problem by
aggressive leaning on the ground or switch to an unleaded fuel.
Linn
=====================================
|
Hi Linn:
As you said, Lycoming can't support that. And I'd bet dollars to doughnuts
that there is no data on how long at low RPM it takes to develop lead.
Morristown AP (KMMU) here in NJ has a LONG taxi to and from the runway, over a mile
each way and many times you are waiting for a Jet to get its IFR clearance.
Now, during the taxi it would be recommended to lean aggressively. After all
you are only about 1000 to 1300 RPM not really at the 75% power point 
Better to do the lead scavenging procedure prior to takeoff than at shutdown
(see previous post for reasoning). There are just too many holes in Lycoming's
procedure, it does not make sense. But, then again, what does Lie-Comming do
that ever does make mechanical sense? Ya gots to ask the lawyers!
YES! By all means, use unleaded fuel.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
FLYaDIVE(at)aol.com
Guest
|
| Posted: Wed Aug 09, 2006 8:57 am Post subject: Leaning on ground? |
|
|
In a message dated 8/5/06 1:31:57 PM Eastern Daylight Time,
shempdowling2(at)earthlink.net writes:
| Quote: | So whats a good technique for leaning on the ground.
Shemp/Jeff Dowling
RV-6A, N915JD
295 hours
Chicago/Louisville
===============================
|
Shemp:
That depends on what instrumentation is in the plane. Simple answer, lean to
stumble and then RICH'N three clicks, or three turns or three-sixteenths of
an inch. All you are looking for is a leaner mixture to prevent the lead from
forming. Hell, we're EAA ... EXPERIMENT!
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
HCRV6(at)comcast.net
Guest
|
| Posted: Wed Aug 09, 2006 10:22 am Post subject: Leaning on ground? |
|
|
I've been leaning on the ground to where if I advance the throttle past about 1200 RPM the engine quits. Seems to work since I have no problem with lead fouling. It's also pretty hard to take off if I forget to richen for T.O. (only once, I swear).
--
Harry Crosby
RV-6 N16CX, 250hours
-------------- Original message ----------------------
From: FLYaDIVE(at)aol.com
| Quote: |
In a message dated 8/5/06 1:31:57 PM Eastern Daylight Time,
shempdowling2(at)earthlink.net writes:
> So whats a good technique for leaning on the ground.
>
> Shemp/Jeff Dowling
> RV-6A, N915JD
> 295 hours
> Chicago/Louisville
===============================
Shemp:
That depends on what instrumentation is in the plane. Simple answer, lean to
stumble and then RICH'N three clicks, or three turns or three-sixteenths of
an inch. All you are looking for is a leaner mixture to prevent the lead from
forming. Hell, we're EAA ... EXPERIMENT!
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
|
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
