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ASA Oil Separator

Stockmanreef

Well Known Member
I have the need to reroute the breather tube. I put the main 60 amp fuse and shunt in the path of the breather tube. Oops. So now I will be rerouting the breather tube. I was wondering if it would be worth it to just put in the ASA Oil Separator. I think that I can put it on the left side (opposite the battery).

If not the ASA Oil separator, I will still have to reroute the tube.

Thoughts?
 
I installed the AntiSplat separator (although I used the same breather tube routing) and am very pleased with its performance. I find I only need a belly cleaning about every 20 hours. I opted to collect the oil form the separator rather than recirculate it or burn it, and collect about 3 tablespoons per oil change (40 hours).
 
I have a lightly used ASA separator in the hangar and will sell at a very reasonable price.

Ron B
 
Keith--

Are you using the vacuum evacuation system and are you using stock exhaust or vetterman?

I would like to see pictures of the installation. In particular how you attached to the exhaust.

thanks
ken
 
Keith--

Are you using the vacuum evacuation system and are you using stock exhaust or vetterman?

I would like to see pictures of the installation. In particular how you attached to the exhaust.

thanks
ken

Ken:

My air/oil separator is connected to the engine breather outlet only. I do not route into the exhaust or the sump but collect the "output" for disposal. It is a nominal amount of oil collected on a new engine.

I have a Vetterman "trombone 2 into 1 by 2" as this was originally installed on a Superior XP 400 and the cold air sump would not accommodate the 4 into 1 crossover used by Van's. On my new Lycoming, I transplanted the sump and exhaust.

I have pics, but doubt they would help you since I avoided the exhaust connection. (and with TinyPics demise, I haven't set up a photo sharing method yet.)
 
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Keith.

Thanks. I have all the materials to connect to the sump and the exhaust. I will probably end up doing that unless someone convinces me that it is a waste of time.

As far as pictures go, I gave up on posting pictures. I decided to post everything on a facebook page and direct people there. it is a nice place for a builders log, since you can post videos directly from your phone--sometimes my language is not necessarily polite. I think that I started doing it sometime in the last year. I just assume that FB will be around for quite a while.
 
A couple questions:
According to a few resources the temperature of the air/oil separator unit needs to be above 212F if you're going to put the oil back in your engine otherwise moisture is just superheated and in the oil that goes back in the crankcase.

So the question is: Is a small amount of oil being returned to the crankcase worth it? I can see if your powerplant is spewing oil but on most engines it's only a little.

As far as the crankcase vac on the oil-air separator that seems great as long as you have a bypass in the event of primary failure.

The reason I am asking is I am looking at putting one on my engine(s) as well and would like to avoid the problems others had with regard to failures.
 
According to a few resources the temperature of the air/oil separator unit needs to be above 212F if you're going to put the oil back in your engine otherwise moisture is just superheated and in the oil that goes back in the crankcase.

Very interesting. Could you direct us to these "resources"?
 
Thanks, found it.

https://generalaviationnews.com/2016/03/28/no-1-rule-about-an-air-oil-separator/

Unfortunately, Mr. Visser erred in a few points of physical law.

First, a temperature of 212F (100C) has little relevance. It is merely the temperature at which the vapor pressure of water equals one atmosphere. As human observers, we recognize it as the temperature at which vapor bubbles form in our liquid water at sea level.

However, water and other liquids have a vapor pressure at temperatures both below and above 212F/100C. In the case of water, it is easy to observe by experiment. Put equal amounts of water in three saucers, and place one in the fridge at 35F, one on the countertop at 70F, and one in an oven set at 200F or less. Note the evaporation rates, slow in the fridge, faster on the counter, and pretty quick in the oven. The rate is directly related to the vapor pressures of water at the given temperatures. More important, simply realize all three evaporated; it is not necessary to reach 212F/100C. Raising the temperature merely raises the vapor pressure, evaporating the water faster.

Second, the vapor pressure of motor oil is far, far lower than water. As such, very little oil can reach vapor phase at engine operating temperatures. Again simple observation...the oil in your crankcase does not evaporate, despite being raised well above 100C. It requires something like 500F+ to push the vapor pressure of oil up near one atmosphere, i.e. boil it.

The key here is the very large difference in vapor pressures between water and oil. Separators do not condense oil, as the oil was never in vapor phase. They merely coalesce aerosol droplets, largely by contact. Further, 212F is not required to remove water from oil.

Although 212F would be excessive, Mr. Visser is correct regarding the need to keep separator temperature above the dew point of the water content. We do not want to condense the water, i.e. allow it to move from vapor phase (a gas) to liquid droplets. We want it to remain as gas and exit the system.
 
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Thanks for the explanation. What about pulling vac on the crankcase? Good or bad idea? As long as it's not too much? Would it even help the performance of the engine or just an old wives tale.

Thanks.
 
Thanks for the explanation. What about pulling vac on the crankcase? Good or bad idea? As long as it's not too much? Would it even help the performance of the engine or just an old wives tale.

Theory says a reduction in crankcase air density reduces pumping loss. I can't put a HP value on it; no Lycoming with-and-without dyno data. I have seen positive dyno reports for car engines, ran evac systems on roadrace bikes, and fly one on the 390.
 
I can't figure out how to route the tube down to the exhaust such that I can connect to the gizmo that connects to the exhaust. I don't know where to drill the hole in the exhaust. I guess I should just install the exhaust and then see if I can get the part in place to drain the oil to the interior of the exhaust. Then take off and drill the hole. Otherwise, I think that I might punt and just have the oil drip on to the the exhaust like the plans suggest.

So the Separator will be a waste of time, but It will allow me to route the outlet to the exhaust. Unless I route the oil collection drain to the oil sump.

If any one has pictures of their set up, then that would be helpful.

ken
 
Ken,
I just recently installed the ASA vacuum vent system on my completed O-360 powered RV4. I don?t have, and don?t see a need for the oil separator. Plumbing-wise, my rubber hose vent line comes out of the case, runs to the left of my left mag (Surefly), then down between the baffle mounted oil cooler and engine mount tubes straight down toward the left Vetterman exhaust tube. Before it gets to the exhaust tube, the T-fitting with the safety pop off valve and hose is installed, followed by a short ~6? hose to the vacuum check valve assembly. I had no difficulty drilling the 5/8? hole in the exhaust tube in my RV4 engine compartment. Seems like your RV14 would have more room, so you probably wouldn?t have to remove it to drill the hole. I did need to use a file to make the bias vent tube assembly fit correctly, but the whole installation was pretty quick and easy.

I didn?t take pictures but I can if you are interested. I?m in Nashville for about a week. I can take some pics when I get back if you want.
 
Unless I route the oil collection drain to the oil sump.

ken

There is no problem doing this. the chemical composition of the drain material in the separator is identical to the composition inside the engine (just converted from a gas to a liquid or small aerosolized drops coalesced into liquid). That is where it came from and nothing was added to it. Yes, there is more concentrated liquid water in the separator drainage, but it is a very small percentage of the water already inside your sump. My BMW engine has separators and they drain back into the sump. Can't imagine BMW and other European manufacturers got this wrong.


Larry
 
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I just recently installed the ASA vacuum vent system on my completed O-360 powered RV4. I don’t have, and don’t see a need for the oil separator. Plumbing-wise, my rubber hose vent line comes out of the case, runs to the left of my left mag (Surefly), then down between the baffle mounted oil cooler and engine mount tubes straight down toward the left Vetterman exhaust tube. Before it gets to the exhaust tube, the T-fitting with the safety pop off valve and hose is installed, followed by a short ~6” hose to the vacuum check valve assembly.

I think it's a reasonable choice. The separator just saves a little oil.

Evacuators work better if tapped into a single cylinder's headpipe rather than into a tailpipe, assuming you desire all possible negative case pressure. There is also some empirical evidence that the headpipe tap builds deposits more slowly.

Yes, there is more concentrated liquid water in the separator drainage, but it is a very small percentage of the water already inside your sump.

I want some of that concentrated liquid water. It's got to be worth serious money ;)
 
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Yep, I agree. A head pipe would be better choice for developing negative pressure. I just could find a place inside my tight RV4 cowling to make that happen. I had an Andair air/oil separator on my RV6. It had a beautifully machined aluminum cup that captured the oil, and it needed to be emptied occasionally. I would empty it about every 25 hours. I never had more than a couple teaspoons of sludgy oil in that cup. Maybe it wasn?t catching all the oil, but my belly seemed pretty clean. I considered the ASA oil separator, but at $170, I don?t think I have enough time left to save that much in oil.
 
I put the oil separator in because the electrical system on the FW got in the way of the stock method of getting the oil to the exhaust.

I would like to see how the vacuum vent system is plumbed up. It is a space issue. Regardless as to whether I use the separator. I can't see a reasonable place to drill the hole in the exhaust and keep it near the Y where the stock exhaust comes together.

I am just wondering if the thing that connects to the exhaust has to be vertical or can it be mounted to the side of the exhaust.

Pictures would be nice of any set up.

thanks
ken
 
I?ll take some pics next week. I don?t think there is a requirement for the vent valve assembly to be vertical. On mine it is slightly canted to the outside for clearance/ease of maintenance. I can also shine a flashlight inside the exhaust pipe and just see the end of the vent pipe sticking into the exhaust - to check for coking.
 
Oil Savings! ? !

.... The engines that benefit the most from an oil separator, as far as oil savings
are not the engines that burn a tremendous amount of oil via the piston rings, or
valve guides. The ones that gain the most from this system are the typical Lycoming,
as they actually have a built in design flaw. Due to the age of the design, and the lack
of a willingness to change anything in the aviation world once approved. The design
of the gear case, and accompanying gears are such that they have a tendency for oil
to climb up the gear chain to the top of the gear case where the pilot side magneto
drive gear throws this nice clean oil directly to the breather vent hole in the top of the
case. It is then carried out with any airflow that is present. This is the primary reason
that most people run their Lycoming engines 2 or 3 quarts low on oil as this has a
major effect on how much gets thrown out. We have seen this as well as tested oil
quantity effect many times on our dyno. When running a Lycoming on our dyno with
even moderate HP output and RPM this issue is very obvious and you can see the oil
droplets flying out on the breather hole. This in absolutely clean oil and re-introducing
it back into the engine is no different than it never having left. We have a 12" piece
of 1.25" Id clear vinyl hose we install vertically on the breather outlet when on the
dyno. This catches these large droplets of oil and allows them to just run back into the
engine. The moisture vents off, and blows away just as it does with the oil separators.
Moisture is not collected in our oil separators or re-introduced back to the oil reservoir,
it simply vents off overboard, or to the vacuum evacuator to be consumed in the
exhaust. The other main advantage of the system, and the main reason most are
installed is simply, most people hate to see oil on the belly of their pride and joy.
I am getting to old to crawl around on my back cleaning up all the mess, nor do I
have any desire to. With a properly installed system (baring any oil leaks) the belly
of your aircraft will and should be oil free. If I can help anyone with a question or
concern, just give me a call so we can address them. Thanks, Allan..:D
.
........P.S. Please keep an eye on our website from time to time, as we are soon to
be releasing some very nice new and exciting products!
 
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We have seen this as well as tested oil
quantity effect many times on our dyno. When running a Lycoming on our dyno with even moderate HP output and RPM this issue is very obvious and you can see the oil droplets flying out on the breather hole.

Cool. I want to see pictures of that.

What kind of dyno do you have?
 
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