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  #31  
Old 06-09-2014, 01:00 PM
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DanH DanH is online now
 
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Quote:
Originally Posted by rocketbob View Post
What's the failure mode, do they get carboned up?
In at least one case, yes, coked shut. No idea why.
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  #32  
Old 06-09-2014, 02:59 PM
jgills240 jgills240 is offline
 
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Default 170 hours on my separator

Just to add my experience:

After hearing the usual extremes on what to do with this, I chose to determine the best solution for myself, and run a straight tube (no check valve) into the separator found on ACS: #10570, dump the "air output" tube overboard, and collect the "oil output" in a matco remote brake fluid cylinder. I don't have any numbers from analysis, but I've been running a separator on my IO-320 for just over 170 hours and the biggest thing I've learned from my current setup is I would NEVER want the stuff I pull out of the collector to run back into my engine case.

I fly in So. Cal. for the most part, and when flying in normal So. Cal. WX (clear and dry) I get about 0.25oz of goobery-looking oil schmutz per 10 flight hours. However, when flying in humid conditions, or light mist, the 2oz. capacity reservoir will quickly fill with the usual tiny bit of dino-goober along with 2+ oz. of water.

Now that I've had enough of emptying these goobers, the next step is to plumb the "oil output" into my exhaust rather than collect it, but never back into the engine!
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  #33  
Old 06-09-2014, 04:57 PM
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RV6_flyer RV6_flyer is offline
 
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Quote:
Originally Posted by jgills240 View Post
Just to add my experience:

After hearing the usual extremes on what to do with this, I chose to determine the best solution for myself, and run a straight tube (no check valve) into the separator found on ACS: #10570, dump the "air output" tube overboard, and collect the "oil output" in a matco remote brake fluid cylinder. I don't have any numbers from analysis, but I've been running a separator on my IO-320 for just over 170 hours and the biggest thing I've learned from my current setup is I would NEVER want the stuff I pull out of the collector to run back into my engine case.

I fly in So. Cal. for the most part, and when flying in normal So. Cal. WX (clear and dry) I get about 0.25oz of goobery-looking oil schmutz per 10 flight hours. However, when flying in humid conditions, or light mist, the 2oz. capacity reservoir will quickly fill with the usual tiny bit of dino-goober along with 2+ oz. of water.

Now that I've had enough of emptying these goobers, the next step is to plumb the "oil output" into my exhaust rather than collect it, but never back into the engine!
Over 2,800 hours operating time based out of SoCAL dumping oil separator condensate back into the engine. Pulled cylinders at 2,200 hours and found NO wear on the cam. Engine came off a Piper that had an oil separator that dumped back into the engine using the same port that I am using. Total Time on engine since new is over 5,700.
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  #34  
Old 06-09-2014, 05:17 PM
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DanH DanH is online now
 
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Quote:
I fly in So. Cal. for the most part, and when flying in normal So. Cal. WX (clear and dry) I get about 0.25oz of goobery-looking oil schmutz per 10 flight hours. However, when flying in humid conditions, or light mist, the 2oz. capacity reservoir will quickly fill with the usual tiny bit of dino-goober along with 2+ oz. of water.
Excellent. Can I talk you into a real easy experiment before you re-plumb?

Insulate the hose between the accessory case and the separator. Separator can too, if you're game. Then fly in wet conditions and see if you still get water in the catch bottle.
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  #35  
Old 06-09-2014, 05:22 PM
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FasGlas FasGlas is offline
 
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Quote:
Originally Posted by DanH View Post
In at least one case, yes, coked shut. No idea why.
The valve and hoses are very easy to check at every annual.
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  #36  
Old 06-09-2014, 06:27 PM
SHIPCHIEF SHIPCHIEF is offline
 
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I've had the opposite experience to Jgillis240;
My O-290 (T-18) vent tube is very short. It ends near the oil cooler in the bottom of a small plastic baby bottle with holes around the top to let vapors escape, yet collect 'most' of the oil. That oil is always very clean. I never put it back in the engine, on principle, because dust could enter the bottle thru the holes around the top, but I'm getting clean oil in the bottle, even after flights on cold days.
I'm agreeing with what I think is Dan's point, that the vapor should be hot all the way through the separator process so no condensation occurs in there. Short or insulated lines would be good.
All the water vapor and combustion gas / carbon /acids will pass through if kept warm enough.
Allan has a good point as well, (also made buy TitanXpert) the gear case on the back of the engine can pull oil up thru the meshing of the timing gears and deposit some of it in the oil separator cavity, which has a somewhat effective sheet metal separator.
A final point to keep this in perspective: All that vapor being extracted is already fully saturating the oil inside the engine. It's blowing around the rings and the piston skirts directly into the fog of oil flinging off the crankshaft. Putting back oil that has had the water & blow by gas removed is not returning oil to the engine that is dirtier than the oil inside the engine. It's simply finishing the job the internal Lycoming separator can't do.
Why don't I have one on my plane?
I'm a weight fanatic.
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  #37  
Old 06-10-2014, 10:01 AM
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PerfTech PerfTech is offline
 
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Quote:
Originally Posted by SHIPCHIEF View Post
Allan has a good point as well, (also made buy TitanXpert) the gear case on the back of the engine can pull oil up thru the meshing of the timing gears and deposit some of it in the oil separator cavity, which has a somewhat effective sheet metal separator.
A final point to keep this in perspective: All that vapor being extracted is already fully saturating the oil inside the engine. It's blowing around the rings and the piston skirts directly into the fog of oil flinging off the crankshaft. Putting back oil that has had the water & blow by gas removed is not returning oil to the engine that is dirtier than the oil inside the engine. It's simply finishing the job the internal Lycoming separator can't do.
Why don't I have one on my plane?
I'm a weight fanatic.
....Good day guys
....Keep in mind that this little separator only weighs about 6 oz and it will save at the very least its weight in oil hourly. This, times a 50 hour oil change, times all the RVs and voila, we have reduced our middle east oil dependance dramatically, thus saving the world!!! Think Green!!!! Do your part now and order yours today while supplies last... Isn't this forum great?...
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  #38  
Old 06-10-2014, 11:12 AM
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DanH DanH is online now
 
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Quote:
Originally Posted by SHIPCHIEF View Post
I'm agreeing with what I think is Dan's point, that the vapor should be hot all the way through the separator process so no condensation occurs in there. Short or insulated lines would be good.
Exactly.

Breather gas water content has two sources. Water is a major product of combustion; we take a hydrocarbon, combine it with oxygen, and produce CO2 and H2O. How much H2O depends on available oxygen and how many hydrogens are available in the fuel, but won't vary a lot. The second source is atmospheric water entering with the intake air. Obviously that can vary.

Dew point rises and falls with water content; lots of water = high dew point, not much water = low dew point.

Justin describes finding liquid water in his catch can only when operating in conditions of significant atmospheric water. I'm suggesting that his breather gas is cooling enough to reach the dew point when breather water content is high, but not enough to reach the reduced dew point when water content is limited to combustion product only. Insulate the breather hose and separator, reduce heat loss, and perhaps the gas temperature will stay above the "wet" dew point.

BTW, in the context of separators, high oil temperature is good.
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  #39  
Old 12-13-2014, 08:48 AM
Boyd Birchler Boyd Birchler is offline
 
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Location: IN
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Default Oil seperator

My experience is different. Most of the engines I (I'm an IA/AP) have seen torn down have been from aerobatic aircraft that all had an oil separator that put the breather oil return back into the crankcase.

I can say from extensive experience that I have never observed any visible damage to the engine because of the use of the oil separator in the breather line and it's return of oil back to the crankcase!
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  #40  
Old 07-12-2020, 04:12 PM
vanremog vanremog is offline
 
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Quote:
Originally Posted by Mike S View Post
Just a thought here, but I wonder....................

How much would the other 14 locations leak if the crankcase was under vacuum as happens with the vent line attached to the exhaust ???
The exhaust is not a vacuum. The intake would be, but not the exhaust.
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