VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 07-16-2017, 12:38 PM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,855
Smile

Quote:
Originally Posted by GalinHdz View Post
FWIW I have broken in several engines (3 Lycomings, 2 Continentals) and this is how I was told and did it.

1 - Minimize the taxi and idle time. Keep track of oil consumption.
2 - After takeoff, keep the engine between 75-85% power at all times.
Fly for at least 1hr at between 75-85% power.
3 - After the engine has 3+hrs on it, do a "long" cross country of
2+ hours at about 75% power. Let the engine cool to the touch
(can anybody say lunch) then fly back at about 75% power.
4 - After this the oil consumption should have stabilized. If not, do as
many "long" cross countries needed until it stabilizes never cruising
below 75% power..

If you have CHT on each cylinder, at some point you will see a significant drop in CHT over what you had when you started. Mine dropped almost 75degF but they did not drop at the same time. In the last break in (Conti O-200) the #3 cylinder took almost 15hrs before the CHT dropped significantly.

YMMV

Thanks for the info -


1 - Minimize the taxi and idle time. Keep track of oil consumption.


I've tried, but have a long taxi to the runwway. My first few flights were from a borrowed hangar with a short taxi distance. I never did "taxi testing". The last flight had a very slow taxi behind a Waco with a student under instruction.

Oil consumption was reasonably tracked as I mentioned.

2 - After takeoff, keep the engine between 75-85% power at all times.
Fly for at least 1hr at between 75-85% power.


Can't seem to do that percentage with our temperatures and altitude. Our absolute daily lows give a take off DA of about 4500 ft.
My test flights have been much shorter though as I examined the instrumentation, aerodynamics and control.

3 - After the engine has 3+hrs on it, do a "long" cross country of
2+ hours at about 75% power. Let the engine cool to the touch
(can anybody say lunch) then fly back at about 75% power.


Haven't done that, but sounds like a good idea for my next flight. The cross country will be have to be a zig-zag with the 100 nm mile Phase I limit.


4 - After this the oil consumption should have stabilized. If not, do as
many "long" cross countries needed until it stabilizes never cruising
below 75% power..


Sounds like a good plan. Perhaps I should do this before chasing IAS accuracy issues.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #12  
Old 07-16-2017, 12:44 PM
Chkaharyer99 Chkaharyer99 is offline
 
Join Date: Oct 2011
Location: Pilot Hill, CA
Posts: 874
Default

Gil,

You are the master of research. I bet you already have this information but in case you don't.

LYCOMING

Hard Facts About Engine Break-In

https://www.lycoming.com/content/har...t-engine-break

LYCOMING

Service Instructions

Lycoming*Reciprocating*Engine*Break*In and*Oil Consumption*

https://www.lycoming.com/sites/defau...onsumption.pdf
__________________
Charlie
RV-8
Reply With Quote
  #13  
Old 07-16-2017, 12:46 PM
GalinHdz's Avatar
GalinHdz GalinHdz is offline
 
Join Date: Mar 2010
Location: KSGJ / TJBQ
Posts: 1,368
Default

Quote:
Originally Posted by az_gila View Post
Thanks for the info -


1 - Minimize the taxi and idle time. Keep track of oil consumption.


I've tried, but have a long taxi to the runwway. My first few flights were from a borrowed hangar with a short taxi distance. I never did "taxi testing". The last flight had a very slow taxi behind a Waco with a student under instruction.

Oil consumption was reasonably tracked as I mentioned.

2 - After takeoff, keep the engine between 75-85% power at all times.
Fly for at least 1hr at between 75-85% power.


Can't seem to do that percentage with our temperatures and altitude. Our absolute daily lows give a take off DA of about 4500 ft.
My test flights have been much shorter though as I examined the instrumentation, aerodynamics and control.

3 - After the engine has 3+hrs on it, do a "long" cross country of
2+ hours at about 75% power. Let the engine cool to the touch
(can anybody say lunch) then fly back at about 75% power.


Haven't done that, but sounds like a good idea for my next flight. The cross country will be have to be a zig-zag with the 100 nm mile Phase I limit.


4 - After this the oil consumption should have stabilized. If not, do as
many "long" cross countries needed until it stabilizes never cruising
below 75% power..


Sounds like a good plan. Perhaps I should do this before chasing IAS accuracy issues.
Oh I forgot. Don't worry about leaning at all unless your DA causes the engine to run rough. If so only lean until the engine runs smooth. During the break in, keep the mixture as rich as possible for engine cooling and to prevent detonation. Until the engine breaks in don't worry about fuel consumption. After break in (the rest of the engine lifespan) fuel consumption for a given amount of power will be significantly better than if you ran it too lean during the break in.

__________________
Galin
CP, ASEL, AMEL, IR
St. Augustine, FL
www.puertoricoflyer.com

Last edited by GalinHdz : 07-16-2017 at 12:48 PM.
Reply With Quote
  #14  
Old 07-16-2017, 12:49 PM
Chkaharyer99 Chkaharyer99 is offline
 
Join Date: Oct 2011
Location: Pilot Hill, CA
Posts: 874
Default

Quote:
Originally Posted by az_gila View Post
Thanks for the info -


1 - Minimize the taxi and idle time. Keep track of oil consumption.


I've tried, but have a long taxi to the runwway. My first few flights were from a borrowed hangar with a short taxi distance. I never did "taxi testing". The last flight had a very slow taxi behind a Waco with a student under instruction.

Oil consumption was reasonably tracked as I mentioned.

2 - After takeoff, keep the engine between 75-85% power at all times.
Fly for at least 1hr at between 75-85% power.


Can't seem to do that percentage with our temperatures and altitude. Our absolute daily lows give a take off DA of about 4500 ft.
My test flights have been much shorter though as I examined the instrumentation, aerodynamics and control.

3 - After the engine has 3+hrs on it, do a "long" cross country of
2+ hours at about 75% power. Let the engine cool to the touch
(can anybody say lunch) then fly back at about 75% power.


Haven't done that, but sounds like a good idea for my next flight. The cross country will be have to be a zig-zag with the 100 nm mile Phase I limit.


4 - After this the oil consumption should have stabilized. If not, do as
many "long" cross countries needed until it stabilizes never cruising
below 75% power..


Sounds like a good plan. Perhaps I should do this before chasing IAS accuracy issues.


The Lycoming website indicates:

"A new, rebuilt or overhauled engine should receive the same start, warm-up and preflight checks as any other engine. There are some aircraft owners and pilots who would prefer to use low power settings for cruise during the break-in period. This is not recommended. A good break-in requires that the piston rings expand sufficiently to seat with the cylinder walls. This seating of the ring with the cylinder wall will only occur when pressures inside the cylinder are great enough to cause expansion of the piston rings. Pressures in the cylinder only become great enough for a good break-in when power settings above 65% are used."

"Full power for takeoff and climb during the break-in period is not harmful; it is beneficial, although engine temperatures should be monitored closely to ensure that overheating does not occur. Cruise power settings above 65%, and preferably in the 70% to 75% of rated power range, should be used to achieve a good engine break-in."

"Remember that if the new or rebuilt engine is normally aspirated (non-turbocharged), it will be necessary to cruise at lower altitudes to obtain the required cruise power levels. Density altitudes in excess of 8000 feet (5000 feet is recommended) will not allow the engine to develop sufficient cruise power for a good break-in.
"
__________________
Charlie
RV-8
Reply With Quote
  #15  
Old 07-16-2017, 12:57 PM
GalinHdz's Avatar
GalinHdz GalinHdz is offline
 
Join Date: Mar 2010
Location: KSGJ / TJBQ
Posts: 1,368
Default

True, but this is where theory runs into reality.

Unless the engine is on an accurate dynamo very few people can accurately measure a 5% difference in power even with advanced engine monitoring systems installed in the aircraft. Too many uncontrolled variables while flying. In an engine break in, going slightly above the requirement is better than going slightly below the requirement. Besides we all want to "baby" our expensive engine so we will tend to do things on the lower side of the requirement.

__________________
Galin
CP, ASEL, AMEL, IR
St. Augustine, FL
www.puertoricoflyer.com

Last edited by GalinHdz : 07-16-2017 at 01:00 PM.
Reply With Quote
  #16  
Old 07-16-2017, 01:09 PM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,855
Smile

Quote:
Originally Posted by Chkaharyer99 View Post
The Lycoming website indicates:

"A new, rebuilt or overhauled engine should receive the same start, warm-up and preflight checks as any other engine. There are some aircraft owners and pilots who would prefer to use low power settings for cruise during the break-in period. This is not recommended. A good break-in requires that the piston rings expand sufficiently to seat with the cylinder walls. This seating of the ring with the cylinder wall will only occur when pressures inside the cylinder are great enough to cause expansion of the piston rings. Pressures in the cylinder only become great enough for a good break-in when power settings above 65% are used."

"Full power for takeoff and climb during the break-in period is not harmful; it is beneficial, although engine temperatures should be monitored closely to ensure that overheating does not occur. Cruise power settings above 65%, and preferably in the 70% to 75% of rated power range, should be used to achieve a good engine break-in."

"Remember that if the new or rebuilt engine is normally aspirated (non-turbocharged), it will be necessary to cruise at lower altitudes to obtain the required cruise power levels. Density altitudes in excess of 8000 feet (5000 feet is recommended) will not allow the engine to develop sufficient cruise power for a good break-in.
"
And the DA is my problem in this heat and monsoon season.

I think a long zig-zag cross-country out in the wilds of the Gil Bend area where the ground is 1000 to 1500 msl is called for.

I just prefer not to fly that low over the empty, unpopulated AZ desert wilderness miles from civilization.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #17  
Old 07-16-2017, 02:10 PM
snopercod's Avatar
snopercod snopercod is offline
 
Join Date: Aug 2016
Location: Asheville, NC
Posts: 867
Default

My breakin was weird; I never did determine if or when it was done. After two hours I mumbled a prayer, made the sign of the cross over the engine and called it complete. My cylinders are Cermichrome, and I didn't experience any significant oil consumption at all; I still don't after 175 hrs. These days I'll usually add 1/2 qt. between 25 hr. oil changes so I guess I must have accidentally done something right. I did experience high CHTs (440ish) for the first few hours, but that was before I drilled out my carburetor jet. My takeoff fuel flow was only 8 GPH when it should have been more like 11 GPH for my O-290-D2.
__________________
(2017 dues paid)
Reply With Quote
  #18  
Old 07-16-2017, 02:44 PM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,855
Default

Quote:
Originally Posted by snopercod View Post
My breakin was weird; I never did determine if or when it was done. After two hours I mumbled a prayer, made the sign of the cross over the engine and called it complete. My cylinders are Cermichrome, and I didn't experience any significant oil consumption at all; I still don't after 175 hrs. These days I'll usually add 1/2 qt. between 25 hr. oil changes so I guess I must have accidentally done something right. I did experience high CHTs (440ish) for the first few hours, but that was before I drilled out my carburetor jet. My takeoff fuel flow was only 8 GPH when it should have been more like 11 GPH for my O-290-D2.
That's exactly what happened after a TOH on my Tiger a few years back, and why I'm not sure what to expect, or what I'm seeing, on the RV-6A.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #19  
Old 07-16-2017, 02:50 PM
GalinHdz's Avatar
GalinHdz GalinHdz is offline
 
Join Date: Mar 2010
Location: KSGJ / TJBQ
Posts: 1,368
Default

Quote:
Originally Posted by az_gila View Post
And the DA is my problem in this heat and monsoon season.

I think a long zig-zag cross-country out in the wilds of the Gil Bend area where the ground is 1000 to 1500 msl is called for.

I just prefer not to fly that low over the empty, unpopulated AZ desert wilderness miles from civilization.
The good thing is that you probably only have to do it once or maybe twice for a good engine break in. 7,500' DA at WOT, as rich as possible for smooth operation for 2hrs is close enough to 75% and should do the trick.

__________________
Galin
CP, ASEL, AMEL, IR
St. Augustine, FL
www.puertoricoflyer.com

Last edited by GalinHdz : 07-16-2017 at 02:52 PM.
Reply With Quote
  #20  
Old 07-16-2017, 02:58 PM
jrs14855 jrs14855 is offline
 
Join Date: Apr 2008
Location: Lake Havasu City AZ
Posts: 2,005
Default Break In

I pay a lot of attention to what Mahlon Russell says and not so much to others. I do not have access to my notes but my recollection is that Mahlon recommends an absolute maximum of 425 CHT until you are CERTAIN the rings have seated. Anything higher and you are in an area where glazing the cylinder walls is likely.
Pulling the throttle back for a minute of two on initial climb is FAR BETTER than glazing the cylinders.
With the 0 320 at 6000' PRESSURE ALTITUDE 21" mp and 2650 r/m I was still at 75% according to the Lycoming power chart.
If you are close to full throttle and below 5k pressure altitude you should be fine. How many total hours??
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:08 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.