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  #1  
Old 07-16-2017, 10:15 AM
az_gila's Avatar
az_gila az_gila is offline
 
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Question Break In - when is it done?

A question for the Lycoming experts.

How do you know when a new engins is broken in?

I have a newly built up narrow deck O-360-A1A that had 1.5 hrs on a test stand and was then installed on my RV-6A.The plane first flew in May, but I then spent 4 weeks in the UK and returned to the AZ June heatwave...

Living at 3000 MSL and with the lows in the 80s it's hard to get the high percent power all of the literature tells you to run at. CHTs are still running hot in climb and also when I try to lean at 2500 rpm (FP Sensenich). Oil consumption is pretty low, perhaps less than 1/4 in on the dipstick in 7 hours.

Is there any other way of checking for break-in completion? I'm going to do a first oil change soon, so if I remove the plugs could a borescope tell me anything?

Test flying progress -

IAS issues. Non-standard flush static ports have been modified but the now arrived monsoon season doesn't give still air for accurate testing even in the early morning.

The old, but sat quietly on the shelf, Facet 40108 fuel pump failed after 6 flights.
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Last edited by az_gila : 07-16-2017 at 10:37 AM.
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  #2  
Old 07-16-2017, 10:35 AM
flyinga flyinga is offline
 
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I would say that since it had 1.5 on the dyno/test stand, plus a bit of your flying and your oil usage has stabilized that it is good to go.
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  #3  
Old 07-16-2017, 10:40 AM
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Quote:
Originally Posted by flyinga View Post
I would say that since it had 1.5 on the dyno/test stand, plus a bit of your flying and your oil usage has stabilized that it is good to go.
I was sort of thinking the same thing, but when the literature says oil consumtion stabilises, how much oil is used before this stabilisation, ozs or quarts?

The literature also says to expect CHTs to drop, but I don't see that yet.
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  #4  
Old 07-16-2017, 10:41 AM
jrs14855 jrs14855 is offline
 
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Default Break In

Gil-
I have a 0 320 with 10-1 pistons, fixed pitch prop, Lycoming nitride cylinders. Wittman Tailwind. All my testing was done in late July, 100-120 plus temps for takeoff.
There was a small but identifiable drop in CHT after only a couple of hours. Less than half a quart oil the first 10 hours and zero oil consumption after that. I did everything necessary to keep the CHT below 400. I did see 425 momentarily on the first flight, reduced power and increased speed, it dropped below 400. I ran high power for the first ten hours but probably not quite 75%. I did not lean at all for at least ten hours.
Once the rings are seated 425 CHT in initial climb will not hurt anything.
Apples to Oranges but the six cylinder Continentals run near red line all summer in AZ, both oil and CHT.
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  #5  
Old 07-16-2017, 10:53 AM
Chkaharyer99 Chkaharyer99 is offline
 
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Quote:
Originally Posted by az_gila View Post
A question for the Lycoming experts.

How do you know when a new engins is broken in?

CHTs are still running hot in climb and also when I try to lean at 2500 rpm (FP Sensenich).
How hot are your CHTs getting?

Does it recover any when you level off and speed up?
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  #6  
Old 07-16-2017, 10:53 AM
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Quote:
Originally Posted by jrs14855 View Post
Gil-
I have a 0 320 with 10-1 pistons, fixed pitch prop, Lycoming nitride cylinders. Wittman Tailwind. All my testing was done in late July, 100-120 plus temps for takeoff.
There was a small but identifiable drop in CHT after only a couple of hours. Less than half a quart oil the first 10 hours and zero oil consumption after that. I did everything necessary to keep the CHT below 400. I did see 425 momentarily on the first flight, reduced power and increased speed, it dropped below 400. I ran high power for the first ten hours but probably not quite 75%. I did not lean at all for at least ten hours.
Once the rings are seated 425 CHT in initial climb will not hurt anything.
Apples to Oranges but the six cylinder Continentals run near red line all summer in AZ, both oil and CHT.
Using the 410 F limit on SavvyAnalysis with the Skyview data, my excursions above that number are only for 2 to 4 minutes, usually on takeoff.

Oil temps are good, and have never passed 194 F

Perhaps after one more flight I'll do the oil change and keep an accurate track of the consumption.

Anyone have any opinions on having an oil analysis on a 10 hr new engine? Is it worth it?
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Grumman Tiger N12GA - flying
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  #7  
Old 07-16-2017, 11:04 AM
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Quote:
Originally Posted by Chkaharyer99 View Post
How hot are your CHTs getting?

Does it recover any when you level off and speed up?
Abolute peak has been 433, but for only a few minutes. Speeding up a bit in climb (to 110 - 120 kts) doesn't seem to help with the FP prop since it just gets more rpms. Pulling the throttle back helps...

Leveling off for cruise they are just below 400 F and all close - within 15 F - with #4 usually being the hottest with the oil cooler mounted behind it. EGTs are also close, usually within 30 F.

TAS (acutally GPS ground spoeed due to IAS issues) is about 150 kts and I'm still flying without any wheel pants or gear farings. I'll put them on when I do the oil change.
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Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ

Last edited by az_gila : 07-16-2017 at 11:12 AM.
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  #8  
Old 07-16-2017, 11:10 AM
PilotjohnS PilotjohnS is offline
 
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Default My experience

I was flying a spam can with a new O320. Mechanic told me to run WOT as much as possible. Cruising along just after climbout, the rpm started to pick up and Noticeable increase in power. It was quite dramatic, like it gain 10 horsepower. Not sure if this is typical or not.
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  #9  
Old 07-16-2017, 11:27 AM
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GalinHdz GalinHdz is offline
 
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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 during cruise.
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.

Quote:
Originally Posted by PilotjohnS View Post
I was flying a spam can with a new O320. Mechanic told me to run WOT as much as possible. Cruising along just after climbout, the rpm started to pick up and Noticeable increase in power. It was quite dramatic, like it gain 10 horsepower. Not sure if this is typical or not.
I have had that same experience in all 5 of my break ins. Was told this is typical of when a cylinder is broken in. When all cylinders have broken in the increase is noticeable over when you started.

YMMV

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Last edited by GalinHdz : 07-16-2017 at 11:37 AM.
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  #10  
Old 07-16-2017, 11:34 AM
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GalinHdz GalinHdz is offline
 
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Quote:
Originally Posted by az_gila View Post
Anyone have any opinions on having an oil analysis on a 10 hr new engine? Is it worth it?
IMHO the 1st oil analysis is to establish a baseline in order to compare all others. Until the engine is fully broken in and not running "break in" oil (typically 100% mineral), any oil analysis would have little to no value as a baseline. Until the engine is broken in and internal parts fall into their permanent state, you will have all kinds of "weird" oil sample indications.

I do the 1st oil analysis after the break in is complete and after I have one oil change with the oil I will be running (typically ashless dispersant).

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Last edited by GalinHdz : 07-16-2017 at 11:40 AM.
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