Break in metal

[toomany]

Anybody have an idea of what is an acceptable amount of metal in a filter during break in?  We ran straight mineral oil in the bravo for the first three hrs then changed to Phillips 20/50xc and changed again at 9 hrs.  First filter and oil (we strained oil through a t shirt)had noticeably more alum in it than second, but not an amount I thought inordinate for 90cu. cylinders - an area of approx 8 inches in diameter looked like someone had sprinkled a small pinch of glitter on it.   I washed down the filter elements in mineral spirits and strained the spirits through coffee filters.  First filter had approx enough alum/metal to cover a dime with a thin coating. Second had less than half that amount. I’m running b/t 34/24 and 32/24 w occasional full power - when I see boost pump come on at fuel power I twist the throttle back until the light goes out - full power for about 3 min. only.  All cht’s are great (330-380 range) except #5 that goes to 400 if I get too greedy w the cowl flaps on SLOW climbs, otherwise it seems to stabilize at 389 w flaps closed at 4-6000’ and 34/24 or 32/24. I’m not pulling too much fuel out of it at this point - typically run tit at 1580-1600.  My question is: how long should I run these power settings and what is too hot for a cylinder in a bravo.  I was also wondering has anyone added 2-stroke oil to their tanks at break in and/or beyond   I know some guys that run pressurized drag bikes and they swear by adding a small amount of high grade 2-stroke oil to their fuel to keep the top end better lubricated as the  higher pressures  tend to blow oil down the bores.  

next oil change will be in about 15hrs 

[A64Pilot]

Do NOT add anything to the fuel, especially non approved additives like two stroke oil. two stroke oil among other things is very unlikely to improve any lubrication as the whole cylinder gets washed in undiluted oil under the rings and also it reduces the octane of fuel.

Don’t do anything the engine manufacturer doesn’t recommend, these engines have been being overhauled for a very long time, the approved process works.

Your metal seems normal to me, although I’d change oil more frequently until it stops making metal. Most of that metal may be simply being washed out and not actual wear material depending on what and how much machining was done. I want the metal flushed out quickly.

Engines with problems increase the amount of metal they make and from what I’ve seen, if there is a problem, you get LOTS of metal, and quickly.

Cylinder break in is done when oil consumption stabilizes and on engines I’ve overhauled that has always happened rather quickly, but most of my experience is with NA engines, blown motors ought to break in even faster.

[LANCECASPER]

On 12/19/2021 at 9:05 AM, toomany said:

Anybody have an idea of what is an acceptable amount of metal in a filter during break in?  We ran straight mineral oil in the bravo for the first three hrs then changed to Phillips 20/50xc and changed again at 9 hrs.  First filter and oil (we strained oil through a t shirt)had noticeably more alum in it than second, but not an amount I thought inordinate for 90cu. cylinders - an area of approx 8 inches in diameter looked like someone had sprinkled a small pinch of glitter on it.   I washed down the filter elements in mineral spirits and strained the spirits through coffee filters.  First filter had approx enough alum/metal to cover a dime with a thin coating. Second had less than half that amount. I’m running b/t 34/24 and 32/24 w occasional full power - when I see boost pump come on at fuel power I twist the throttle back until the light goes out - full power for about 3 min. only.  All cht’s are great (330-380 range) except #5 that goes to 400 if I get too greedy w the cowl flaps on SLOW climbs, otherwise it seems to stabilize at 389 w flaps closed at 4-6000’ and 34/24 or 32/24. I’m not pulling too much fuel out of it at this point - typically run tit at 1580-1600.  My question is: how long should I run these power settings and what is too hot for a cylinder in a bravo.  I was also wondering has anyone added 2-stroke oil to their tanks at break in and/or beyond   I know some guys that run pressurized drag bikes and they swear by adding a small amount of high grade 2-stroke oil to their fuel to keep the top end better lubricated as the  higher pressures  tend to blow oil down the bores.  

next oil change will be in about 15hrs 

Follow Lycoming's instructions on break in for temperatures and limitations. 

 

Why did you run mineral oil in the Bravo engine after overhaul when Lycoming specifically says not to run mineral oil after break-in in their turbo-charged engines?

 

 

[N201MKTurbo]

I was conflicted when I broke in my new engine. It isn't a turbocharged Lycoming, it is a NA Lycoming with a turbo. I ran mineral oil for the first 5 hours and then ran 100W since.

No oil consumption and no metal in the filter or screens.

[201Steve]

This is an interesting question- Amount of metal in the filter after overhaul. I've seen a wide array or reports from a lot, to some, to none. Most of which have ended up favorably in the end. It begs the question, does a "no metal" filter inspection after an overhaul indicate a better overhaul job? Is there any correlation at all to a "good overhaul" and the discovery of metal (or lack thereof?) in the first 1-3 oil changes? Things to ponder....

[A64Pilot]

23 hours ago, 201Steve said:

This is an interesting question- Amount of metal in the filter after overhaul. I've seen a wide array or reports from a lot, to some, to none. Most of which have ended up favorably in the end. It begs the question, does a "no metal" filter inspection after an overhaul indicate a better overhaul job? Is there any correlation at all to a "good overhaul" and the discovery of metal (or lack thereof?) in the first 1-3 oil changes? Things to ponder....

Assuming it’s properly done there is almost never any metal from break-in, and what there is is almost microscopic.

Mchining tolerances are simply light years ahead of where they were when these engines were designed.

Most metal I maintain comes from the machining processes and wasn’t cleaned out well enough, try this on a recently overhauled cylinder, clean it out with mineral spirits or a rag and auto xmsn fluid or whatever your favorite cleaning is, then after your sure it’s clean, clean it again with a rag and hot soapy water, you’ll be surprised at how much grey material you get out, that material is of course stone from honing and metal from the cylinder.

Hot soapy water cleans very well

You’ll also be surprised how fast that cylinder will flash rust if you don’t immediately dry and oil it.

Assuming the machining is properly done, a good overhaul is essentially already broken in, which is not to say don’t follow break in procedures, just don’t be surprised if your engine never burns excess oil, even in the first five hours.

 

[201Steve]

33 minutes ago, A64Pilot said:

Assuming it’s properly done there is almost never any metal from break-in, and what there is is almost microscopic.

Well my botched overhaul this year would corroborate that, anyway. I wasn’t particularly concerned with the metal flakes in the first 3 oil changes, but maybe I should have been more critical of that variable. Other symptoms forced an overhaul 2.0

[cujet]

On 12/19/2021 at 10:05 AM, toomany said:

Anybody have an idea of what is an acceptable amount of metal in a filter during break in?   

As DOM in a high end flight department, we have regularly overhauled engines and components. The results vary wildly. Our recently overhauled EC135 helicopter transmission is illuminating the chip light about every 5th flight. That's way beyond the MM allowances. However, when we pull the chip detector, what's on there is less than a whisker of particulates. Attempts to wipe it off results in a 0.010 dark smudge on a rag. Factory says to expect this for 150 hours. 

Brand New Pratt PW815 engines are also giving us chip lights!   

I don't get worried with modest metal in the filters in our piston or turbine engines, either when new or overhauled. I only worry when the trend is strongly the wrong direction. Heck, our new Extra NG with it's AEIO-580 engine is having low oil pressure indications on final, likely due to higher than normal cylinder head and oil temperatures! It will be interesting to see what ends up in the filter. In any case, the factory says "it's normal". 

It is very likely that "if" the engine has a failing component, you will know about it in short order. 

Disclaimer: I've not seen your filter. But from your description, I'd put it in the normal category. 

 

 

 

 

Edited December 24, 2021 by cujet

[ArtVandelay]

Isn’t it standard for a shop to run it on a test stand, then drain the oil and pull the filter, so owner should see no metal?

[Guest]

A couple of Lycoming documents to help you.

https://www.lycoming.com/sites/default/files/Lycoming Reciprocating engine Break-In and Oil Consumption.pdf

https://www.lycoming.com/sites/default/files/SB480F Oil ServicingMetallic Solids Identification After Oil Servicing and Associated Corrective Action.pdf

Clarence

[toomany]

7 hours ago, cujet said:

As DOM in a high end flight department, we have regularly overhauled engines and components. The results vary wildly. Our recently overhauled EC135 helicopter transmission is illuminating the chip light about every 5th flight. That's way beyond the MM allowances. However, when we pull the chip detector, what's on there is less than a whisker of particulates. Attempts to wipe it off results in a 0.010 dark smudge on a rag. Factory says to expect this for 150 hours. 

Brand New Pratt PW815 engines are also giving us chip lights!   

I don't get worried with modest metal in the filters in our piston or turbine engines, either when new or overhauled. I only worry when the trend is strongly the wrong direction. Heck, our new Extra NG with it's AEIO-580 engine is having low oil pressure indications on final, likely due to higher than normal cylinder head and oil temperatures! It will be interesting to see what ends up in the filter. In any case, the factory says "it's normal". 

It is very likely that "if" the engine has a failing component, you will know about it in short order. 

Disclaimer: I've not seen your filter. But from your description, I'd put it in the normal category. 

 

 

 

 

Thanks CUJET.  I was thinking metal levels weren’t out of hand but have never run in an aircraft engine, just high performance v-8’s and motorcycles. I plan to run the engine with frequent (15hr) oil changes until 50hrs.  Oil use seems to have normalized at about a qt every 4.5hrs, however I haven’t run it down below 8qts. yet and most of the oil seems to be painting the belly via the blow by tube.  I know on my Comanche the fill cap is 12qts but anything over 9 ends up collecting dust under my feet.  
tbanks for everybody’s input - it is an interesting topic as most times i think we tend to believe that a new or OH’d engine may be good to go for the long haul w/o paying close attention to early indicators. I once had a v-8 that was redone by a reputable shop that had no end gap in the rings, in fact rings couldn’t even rotate on the pistons. I kept blowing head gaskets and never considered faulty assembly.  had I done proper oil analysis early on I’d have seen there were internal issues - final analysis was destroyed pistons and scored cylinders. 
This bird will be spending time over open water so I want to make sure everything looks good from the run in on.  Also thinking about a remote camera where I can view the exhaust outlet/lower cowl in the event a turbo seal gives up the ghost - anybody know of a small remote camera that could be mounted aft of the lower cowl?