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adding an oil separator...

schristo@mac.com

[email protected]

Well Known Member
After nearly 500 hours on the tach I have decided to give an oil separator a try... I have been using one quart of oil every 8 hours; not unreasonable but I seem to get most of it as a fine film on the belly.

Recently Anti Splat Aero added a vacuum check valve to their stable of products to go hand in hand with their oil separator setup. Dan H documented a similar valve installation and is in the process of testing for any real world measurable improvements in performance. I am interested in the potential of what I have read and plan to give the check valve a try this spring for SARL events next year.

For now, I have installed the basic oil separator system to address oil consumption and a dirty belly.

I started by test fitting the separator... looks nice in white but it does mar easily.
img2833ea.jpg


Once satisfied with the location, I removed the standard aluminum tube routing from the breather flex connection to the termination at the exhaust and reused the end fixed to the firewall.
retouched.jpg


After finalizing the location on the firewall I drilled the mount and used a little creative wrenching as a second set of hands ;)
img2837e.jpg


With the breather supply and waste dump lines set I routed the provided oil return fitting and braided line to the suggested accessory case plug. The fitting and length of line worked out great.
img2842xu.jpg


It took a some extra time to retie and secure everything; no big deal and a nice diversion on a crappy weather day... sadly we are in a prolonged stretch of crappy weather.

Here are a couple of shots of the completed installation.
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Afterwords I cleaned and WAXED the belly... did I mention that the weather has been really crappy...

I will report back with results after I get some flight time on the system.
 
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Patiently awaiting the results report....

How's it working...any info yet....how many hours ya got on it?....:D:D:D
 
Check out recent posts on the "Camguard PowerPoint presentation" thread where the developer of Camguard recommends that separators that return oil into the system NOT be used. He makes a good case...

erich
 
Can you give us the one or two line summary on why it's bad to return oil to the engine from a separator? Thanks!
 
The amount of oil out the engine breather is a useful indication of engine problems. They may freeze up blowing out the crankcase nose seal resulting in loss of engine oil. A byproduct of combustion is water. Water, acids and other combustion residuals get pumped back into the engine. For now, I will just get on my creeper, wash and wax the belly every 25 hours. I have been adding a qt to my 540 every 10 hrs and have now decided to keep oil level at 8-9 qts unless on a long xc over hostile terrain or water.
 
Juvat said:
Can you give us the one or two line summary on why it's bad to return oil to the engine from a separator? Thanks!
Click to expand...

The returned oil no doubt includes some suspended water, acids and other contaminants. The issues worth considering are (1) the quantity of contaminants returned, (2) their actual ability to do damage, and (3) does the system concentrate contaminants in the sump oil? Do remember the contaminants in question are present all the time, even with a stock open breather, and start building in fresh oil the first time you crank up after an oil change.

(1) is largely unknown. (2) is pretty clear; they cause corrosion. (3) would be a nice subject for someone currently on an oil analysis program. Install a separator and see how the next analysis is different.

Wayne, at this time there is no reason to believe you can't connect a breather to an exhaust pipe via a reed valve, without a separator. It's done all the time in other applications. The result would likely be a clean belly. I'd guess most folks would assume oil consumption would rise. I don't think so.
 
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So I'm curious as how how the new separator works out for you, been thinking about one of these for my -8... but what I'm really curious about is what I see in the 2nd pic, the Dynon looking doohickey. What is that? Kinda looks like a fancy new com radio but I don't see anything like it on Dynon's website. Can you share with the rest of the class?
 
I built a separator for my airplane out of a couple of soup cans. It did an excellent job of "collecting" the oil that is discarded from the breather. I wanted to collect the oil to see if there was any truth to the contaminates that are always discussed in the " to return to or not to return to" discussion that goes with oil separators. After about 50 hours of oil collection I can report that in my installation the sample of oil was pure gold. There was no moisture, or any other visible contaminates in the oil.
My separator was a bit crude but it proved the point to me and I installed the "Slime Fighter" unit on the engine, available from ACS. The neat thing about this unit is that it installs on top of the breather and the separated oil merely runs back into the engine by gravity. This eliminates any requirement for oil return lines. After 100 hours I can report that the unit works quite well, is not perfect but much much better then without. It has reduced my oil consumption by 50% or two quarts per 25 hours to one quart per 25 hours.
 
Tom Martin said:
After about 50 hours of oil collection I can report that in my installation the sample of oil was pure gold. There was no moisture, or any other visible contaminates in the oil.
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Maybe, but Im not sure that a visual inspection of the oil in your separator tells you much if thats what you did. The water and acids that are of concern are not likely to be visible. And as indicated in a previous post, use of a separator that returns oil to the sump prevents you from being able to monitor the amount of oil that is being discharged, which is a crude indicator of engine health.

erich
 
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Tom Martin said:
I built a separator for my airplane out of a couple of soup cans. It did an excellent job of "collecting" the oil that is discarded from the breather. I wanted to collect the oil to see if there was any truth to the contaminates that are always discussed in the " to return to or not to return to" discussion that goes with oil separators. After about 50 hours of oil collection I can report that in my installation the sample of oil was pure gold. There was no moisture, or any other visible contaminates in the oil.
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It would be interesting to send a sample of what was in the seperator and a sample from the crankcase in for oil analysis. See the difference in level of contaminates. Maybe after 2 or three times, you shed some facts on the debate of returning oil to the crankcase.
 
erich weaver said:
And as indicated in a previous post, use of a separator that returns oil to the sump prevents you from being able to monitor the amount of oil that is being discharged, which is a crude indicator of engine health.
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Don't think the statement made sense the first time. You would quantify belly oil how?
 
Can anyone explain why the oil returned to the crankcase by a separator would necessarily contain more contaminates than the rest of the oil in the crankcase?

I would have assumed that the oil that goes out the breather is simply small droplets of crankcase oil held in suspension in the air and the separator simply collects these droplets into what is essentially the same oil as in the crankcase. :confused:


Fin
9A
 
Finley Atherton said:
Can anyone explain why the oil returned to the crankcase by a separator would necessarily contain more contaminates than the rest of the oil in the crankcase?

I would have assumed that the oil that goes out the breather is simply small droplets of crankcase oil held in suspension in the air and the separator simply collects these droplets into what is essentially the same oil as in the crankcase. :confused:


Fin
9A
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Well the air in the air/oil mixture from the crankcase vent is going to have a lot of the contaminants being discussed. The air/oil separator will allow those contaminants in the air to "fall" back into the oil that the separator will then return back to the sump.
 
DanH said:
Don't think the statement made sense the first time. You would quantify belly oil how?
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Everyone take a deep breath and relax. Like I said, a CRUDE indicator of engine health. If you take a look at the belly of your plane before/after every flight and one day you see more than normal fresh oil, it might be good to evaluate further, no? Sometimes your eyeball alone IS good enough

erich
 
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DanH said:
Don't think the statement made sense the first time. You would quantify belly oil how?
Click to expand...

During every preflight I inspect the bottom of my plane. After cleaning and waxing then a 2 hr trip to Savannah I have a good idea how much oil mist should be on the bottom and how far back the heavier buildup goes. If I show signs of an increased amount I know to investigate further.
 
RVbySDI said:
Well the air in the air/oil mixture from the crankcase vent is going to have a lot of the contaminants being discussed. The air/oil separator will allow those contaminants in the air to "fall" back into the oil that the separator will then return back to the sump.
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Let's theorize a little here.

A good place to start might a categorization of the air/oil mixture into its component parts.....gas, liquid, solid, and vapor. The gas component will contain various materials in a vapor phase as well as liquid materials in droplet suspension. The liquid material will contain various liquid and gas solubles as well as solids in liquid suspension.

If I recall correctly, vapor will not condense to liquid droplets until there is a change in temperature and/or pressure. Although the breather system may allow some cooling it is not a design function. There is no pressure change. Most of the vapor phase contaminants would thus remain with the gas component and pass through the separator to the exit. The liquid materials in droplet suspension would be returned to the sump, the designed function of the separator.

I suspect almost all the water leaves the system as vapor. I'm pretty sure those contaminants limited to liquid transport (notably solids) get returned to the sump where they concentrate (suspended lead salts and carbon particles might be examples). The degree of concentration would be proportional to the quantity of oil normally lost and replaced with new oil. The rest of the chemical stew hard to define, but again, there's no reason to assume anything leaving the case as vapor get returned to the case as liquid.
 
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Let me start by saying I have no idea how much bad stuff may exist in the vapor phase. That being said, just because the breather system is not designed to cool doesnt mean that it doesnt occur. In fact, it almost certainly IS occurring, wouldnt you agree? And so, I would argue that there is indeed likely to be some materials leaving in the vapor phase and returning in the liquid phase. Whether it is significant in the big picture or not, I dont know. All that aside, I dont mind rubbing my airplane's belly once in awhile. Makes her feel good :)

erich
 
Add water, combustion byproducts such as unburned fuel, lead oxides, and nitrogen oxides into your oil bath, aerate with the crankshaft, heat until the water vaporizes and flows through your crankcase breather into the air/oil separator. Here it condenses, especially in cold wx. You now have this creme colored stuff sometimes found on your dipstick being pumped back into the engine along with the oil. The water and nitrogen oxides can form nitric acid. All of this contamination breaks down the oil additives and decreases the ph of your already acidic oil. I rerouted my breather tube to come out near the exhaust, some exhaust pipe staining is evident, but most still goes around it at cruise.
 
DanH said:
I suspect almost all the water leaves the system as vapor. I'm pretty sure those contaminants limited to liquid transport (notably solids) get returned to the sump where they concentrate (suspended lead salts and carbon particles might be examples). The degree of concentration would be proportional to the quantity of oil normally lost and replaced with new oil. The rest of the chemical stew hard to define, but again, there's no reason to assume anything leaving the case as vapor get returned to the case as liquid.
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Note that both the gases and the liquids can carry solid contaminants in suspension, so some contaminants can leave with the gases, but most return with the liquids if you have a separator... The solids will stick to the "sticky" oily sides of the separator. You're right, water leaves as a gas. It can condense in your breather or separator, but by that point is probably beyond the return point anyway. And after 30 minutes of flight, you'd be hard pressed to find any water in your engine at all... Until you shut down, let fresh moist air in, and let it cool.

For the most part, what comes out your breather will be one of two things: First, overspray of the liquids, and "breathing" in and out of the gases, just from the mechanical splashing around that goes on inside. The concentration of contaminants in those liquids and gases won't be any different than the concentration of contaminants in the rest of your oil. The small quantity you lose through the breather won't change the effect the rest of them will have on your engine... ie. if you've got crappy contaminated oil in general, catching a tiny bit of it with your breather line isn't going to make things better in any measurable way.

The second thing that could come out your breather is a large slug of liquid oil, which will happen when you roll your RV inverted and get some negative G by accident. This is really what people want to catch and return to the engine, because losing all of your oil every time you fly upside down will prove to be much harder on the engine in the long run than just returning the oil to the sump where it can continue to lubricate.

If you don't fly aerobatics, and you're seeing any significant amount of oil coming out of your breather, you're either running your engine with too much oil in it to start with, or you've got other engine issues to investigate.
 
That large slug of oil that comes out of the breather during aerobatics is the thing I will be trying to fix with my new oil separator from Antisplat Aero. I was out doing a bunch of aerobatics the other day and started noticing a burning oil smell every time I did over the top maneuvers. That was a little disconcerting to say the least. I landed right away to investigate.

No, I do not have an inverted oil system, no I was not hanging upside down, and I was not doing anything less than about .5 G, certainly not any negative G.

When I got on the ground, my belly was covered with oil. I lost about a 1/2 quart of oil just from aerobatic maneuvering. Hmmm...

Hoping the oil separator helps.
 
3 points

Without meaning to convert anyone one way or the other Id like to make 3 points on this discussion:
1.When a separator is used on certified aircraft they drain back to the sump.
2.When I installed a separator on my Cozy I did before and after oil anylisis specifically asking Blackstone labs about any moisture or acid problems with the oil. The result was negative.
3. Many guys will point to the nasty stuff in their catch can. My opinion on this is the drain from the separator passes both oil and gasses into the catch can. There should be no surprise then the combustion gasses cooled and condensed into a little can will smell and look bad.
I suspect if the catch can were sealed and vented back to the crankcase there would be far less or no "stuff" in the can.
FWIW
Tim
 
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Air oil separator

Several years ago I got into my only serious argument with my Inspector on this subject. I fitted a one to my Tailwind and asked him where I should return the oil back to the engine. He came up with the returning nasty stuff to the engine argument and juts wanted me to vent it overboard or into a catch can.

Well was was the point of fitting it I argued, his response was to say there is no point and I should take it off.

In a previous life I was a mechanic, and one of the reasons gaskets used to blow on some car engines was because the crankcase vent tube used to block with a creamy sludge discharged from the engine, pressurising the crankcase Water droplets would also drip out, so I was well aware of the crud that can come out of a crankcase vent...... what appears to be an oil water suspension.

However, my take on this is. Often the vent tubes on these engines were quite long giving ample time for the gasses to cool and condense on the sides of the tube. Over time this builds up and accelerates leading to the sludge that filled to tube.

What we are fitting to our aeroplane engines is an air oil separator, which is designed to do just that. Secondly, if we keep the tubes to the separator short there is less chance of condensing in the tube forming that suspension. This is relatively easy on a Lycosaurus.

Over time though they can block if not cleaned out, ours did on the Tailwind so they mus be cleaned and say every 50 hours.

Do I have one on my 4, Yes! Oil on the belly is only making a mess, an engine without oil is a dead stick landing and a hefty rebuild bill. Providing the oil is changed regularly there should be no problem, but you have to check these things to make sure they dont block up over time.
 
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erich weaver said:
... just because the breather system is not designed to cool doesnt mean that it doesnt occur. In fact, it almost certainly IS occurring, wouldnt you agree?
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In some installations, yes. Mine, not much. Remember, I'm the guy with a pair of roaming temperature sensors inside the cowl.

I'm also operating the separator/evacuator at 2"~3" Hg less than atmospheric, a slight reduction in boiling point which helps. The pressure is more or less constant all the way to the exit at the reed valve. I say more or less because in practice it oscillates slightly at some multiple of firing frequency; the reed valve is not perfect.

Which is all neither here nor there. Consider comments from Tom and Tim regarding examination of the drainback oil. Nothing like observation, test, and measurement.

Snowflake said:
And after 30 minutes of flight, you'd be hard pressed to find any water in your engine at all... Until you shut down, let fresh moist air in, and let it cool.
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Outside air can't readily enter my breather, as the only port to the atmosphere (via the #4 exhaust header) has a reed valve. Since internal pressure must equalize with external after cooling, it would enter via the intake tract. Is there a difference? I dunno.

For the most part, what comes out your breather will be one of two things: First, overspray of the liquids, and "breathing" in and out of the gases, just from the mechanical splashing around that goes on inside.
Click to expand...

I doubt there is any respiration in and out. It's just out. The driver is combustion gas leaking past the rings. The breather is just another exhaust port, low volume as compared to the others but an exhaust port none the less. What comes out the breather is the same as what comes out the exhaust pipe, with the addition of suspended oil droplets.
 
2300+ hours on my 0320 in the Bucker with the Christen system. If it is returning contaminants in the oil, my engine must like em.....
Sadly, my 6 has a dirty belly. I think I might win the dirty belly contest right now. I clean it once a year whether it needs it or not ;)
(ok, maybe twice a year)
 
And the verdict is?

Dan
Could you please share any performance or other improvements you have seen with your crank case evac system?
I'm running Allan Nimo's separator and have been thinking of adding the exhaust and check valve.
I understand the reduced boiling point benefit, but Allan also claims ~8 HP on a 0-360 using crankcase evacuation. I would expect this can change dramatically depending on the exact placement and angle of the probe.
A local RV guy has found a Jegs threaded fitting that will allow easy changes to the exhaust probe to allow experimentation with angles without welding each time.
 
The biggest problem with oil seperators in my opinion is many folks install them to "cover up" engine problems (excessive oil consumption).

A good running engine that uses less than a qt of oil every 10 hrs will not benefit from and doesn't need a seperator.
 
tim2542 said:
Dan
Could you please share any performance or other improvements you have seen with your crank case evac system?
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Not enough run time to make any specific claims about this Lycoming installation other than a bone dry belly.

I understand the reduced boiling point benefit, but Allan also claims ~8 HP on a 0-360 using crankcase evacuation.
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The boiling point reduction isn't a lot, 4~5 F, but I'll take it.

Case evacuation should increase HP. How much? I'd prefer to see a dyno printout for a Lycoming. What little raw dyno data I've seen for V-8 race motors would have me expecting less than the above 4%. I'd be delighted to be wrong. There is potential because a 4-cyl flat motor has a significant case pumping issue. It forces air volume equal to its displacement through the limited passage area in the center bearing web with each revolution....back and forth, back and forth. Any reduction in air density is a plus.

I would expect this can change dramatically depending on the exact placement and angle of the probe. A local RV guy has found a Jegs threaded fitting that will allow easy changes to the exhaust probe to allow experimentation with angles without welding each time.
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A quick experiment leads me to think the angle of the probe end does not have much effect on the level of vacuum generated. Again, I shall remain cheerfully open minded on that point...show me the numbers.

I am sure there are significant periods of negative pressure within the exhaust header:

http://www.vansairforce.com/community/showthread.php?t=92980&page=3
 
first flight report... bone dry

A thanksgiving morning test flight filled with enough aerobatics to make my head spin... the belly is completely dry and is literally 'squeaky' clean. Glad that I did this BEFORE eating turkey!

I am looking forward to more extensive testing but the initial report is very positive, especially given the round loops with a .5 gee float at the top. After I get some more time of typical flight and light aero to observe the belly I will push some short zero / mild negative gee excursions to see what gets spit out.

Hope that we can get some meaningful real world performance data on adding the vacuum valve.
 
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First, my apologies regarding the quality of the following picture but it is relevant to the discussion.

This is how I collected the oil from my separator for the 50 hour test period. Although the poor picture makes the oil look murky you will just have to take my word for it that it was clean oil, no residue, no water, and no yellow sludge.
I have seen yellow sludge in old farm equipment, neglected auto engines, garden tractors etc but I run about 100 to 120hours a year in my rocket and change the oil every 25 hours. Under those conditions the oil stays pretty clean. If you only fly 25 hours a year and change the oil once then YMMV. The oil sample was drained every once in a while and placed in a separate container. Nothing settled out with time, three to four months.

The black tube that you see is my crankcase breather hose outlet. In this location I measured a -2" ambient pressure drop in the crankcase. I placed the outlet in various locations until I got this minus 2 number. This was done using a water manometer with a fitting on the dip stick cap. Prior to this the breather was dumped directly on to the exhaust pipe, in the cowling area, as most RVs do. In that location the crankcase had a 1" POSITIVE pressure. All my little engine oil leaks disappeared when I moved the vent 2" aft of the cowling (4" aft of the firewall)
Maybe there is a reason why most of the certified aircraft dump their crankcase vent to the exterior of the cowling.....

I am posting this with some reluctance as I have been challenged with this information in the past. Generally speaking it is frowned on to suggest that what Van recommends may not be correct. Most of the time the company is spot on, say 99%of the time. If you disagree with me show me your test information, and we can have a discussion. I may be wrong 99% of the time but I am pretty confident about this 1%!



Uploaded with ImageShack.us
 
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Oil Return All Good!!!!!

....We have been watching this thread develop and decided to chime in. The question of returning nasty by products to the engine is not what actually takes place. The water or moisture based by-products of combustion that are airborne in the breather line are not separated out by our unit. They remain airborne and exit overboard just as before. All modern engines manufactured after about 1970 are sealed crankcase engines without an external breather. The crankcase fumes are routed into the intake and consumed via the PCV valve or inlet of the throttle body. This is not acceptable for aircraft due to possible freezing issues in the air inlet. The automobiles you drive to the airport do not have a road draft tube or external breather pipe (left over from the 1920's design). All modern engines have built in oil separators and much care is taken to see that they do their job and do not blow oil into the intake stream, out on the ground or bottom of the car. To say that the trail you leave is a necessary indicator of engine health is not the case. Modern engines go 6 to 8 thousand miles between oil changes, the oil stays very clean and adding oil between changes is almost non existent. If one develops an engine problem you will know by the oil burn, pressure, performance etc. not by the filth on the belly or your hanger floor. I suppose if one kicks out a quart or two each flight you will never need to change the oil. These units are the finest quality available in workmanship, materials and design. If you find any condition to the contrary or are not happy with the product we will refund no questions asked. We began producing separators for the VariEze and other Burt Rutan creations in 1978 then offering to all other experimentals. We also began to manufacture separators for certified aircraft and aircraft with wet vacuum pumps shortly there after. This isn't new or rocket science, thousands are in aircraft use all over the world. Millions on automobiles and other equipment as well. We have yet to find an unhappy customer. Several hundred RV owners have installed them and not one bad report on this or any other forum. Anyone with questions is welcome to give us a call and we will be happy to answer your concerns. Thank you and merry Christmas to all here on the forums. Allan...:D
 
[email protected] said:
A thanksgiving morning test flight filled with enough aerobatics to make my head spin... the belly is completely dry and is literally 'squeaky' clean. Glad that I did this BEFORE eating turkey!

I am looking forward to more extensive testing but the initial report is very positive, especially given the round loops with a .5 gee float at the top. After I get some more time of typical flight and light aero to observe the belly I will push some short zero / mild negative gee excursions to see what gets spit out.

Hope that we can get some meaningful real world performance data on adding the vacuum valve.
Click to expand...
.
...We are glad to hear you are having good results with your separator and system. We also want to say thank you for posting and stating your opinion. In talking about power gains on our dyno we see about 5 to 8 HP on a typical 180 lycoming at full throttle. This seems to fall in line with the reports we get back from pilots after the installations. We included below a few links to information on the subject of vacuum in the crankcase and power gains. There are virtually hundreds of sites and discussions on the subject as this is accepted practice in all types of racing for efficiency gains. Thanks, Allan...:D
.
http://nutterracingengines.com/racing_oil_pumps/crankcase_vacuum_facts.html
.
http://www.competitionproducts.com/Moroso-Racing-Crankcase-Vacuum-Pump-4-Vane/productinfo/22642/
.
http://speedtalk.com/forum/viewtopic.php?f=1&t=32881&start=0
.
http://www.team-integra.net/forum/15-advanced-tech-corner/10930-crankcase-vacuum-pumps.html
.
http://www.dragstuff.com/techarticles/vacuum-pumps.html
 
air oil separator

A few months back I installed one of Allan's oil separators and check valve. I am very satisfied with the quality of construction, instruction and hardware provided. Like others, a small oil leak at the back of the engine seems to have gone away. Allan asked at the time if I saw any performance increase. Nope. More flying and a little testing have shown my top speed at 8000' density altitude to be 179 knots. Phase One testing was 177 knots. Pretty darn close but a 5 horsepower improvement would provide only about that difference. 5 Horsepower would also give another 100 FPM climb. Is it there? Can't say, don't know if my Phase One testing was accurate to within 100 FPM. One thing for certain is the airplane now has a much cleaner belly.
 
Where does the crankcase vacuum valve go? In between the breather port and the separator? Just trying to understand how that works...
 
Snowflake said:
Where does the crankcase vacuum valve go? In between the breather port and the separator? Just trying to understand how that works...
Click to expand...

Tail end of the system, about 3" from the exhaust header, lower left below...

2wlzo0h.jpg
 
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Been there done that...

Aryana said:
Why not just run the breather tube through the fuse all the way out to the back of the plane? :D
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Good Idea AA,
In fact it was in the original Pitts plans back in the 1950's to set up a rudimentary air/oil separator using just that technique. Many older Pitts still keep an old pork&bean can hanging under the tail tube for the remnant oil to drip in while parked.
When Curtis Pitts met my friend Jim Swick, Jim had designed one of the early inverted fuel/oil systems for Frank Price's Bucker. Curtis liked it and Jim built one for him. Frank Christen scoped it out at an airshow, sat down at his drawing board and the rest is history.
I have installed three Slime Fighters with excellent results. I fly aerobatics pretty much every time I strap my RV on and it does help for the occasional suare' into negative G flight. http://www.aircraftspruce.com/catalog/eppages/slimeftr.php

V/R
Smokey
 
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smokyray said:
Good Idea AA,
In fact it was in the original Pitts plans back in the 1950's to set up a rudimentary air/oil separator using just that technique. Many older Pitts still keep an old pork&bean can hanging under the tail tube for the remnant oil to drip in while parked.
When Curtis Pitts met my friend Jim Swick, Jim had designed one of the early inverted fuel/oil systems for Frank Price's Bucker. Curtis liked it and Jim built one for him. Frank Christen scoped it out at an airshow, sat down at his drawing board and the rest is history.
I have installed three Slime Fighters with excellent results. I fly aerobatics pretty much every time I strap my RV on and it does help for the occasional suare' into negative G flight. http://www.aircraftspruce.com/catalog/eppages/slimeftr.php

V/R
Smokey
Click to expand...

Interesting history. I keep a pan under the tail of my Bucker in the hangar to catch the gunk. The Bucker always has a clean belly, well, except for the "clean" oil that manages to blow back there from my a bit leaky 2300 hour 0320. I would hate to see what the inside of the tube looks like running that far back. Thus far, no blockage. (crossing fingers)
 
Back to the future...

JonJay said:
Interesting history. I keep a pan under the tail of my Bucker in the hangar to catch the gunk. The Bucker always has a clean belly, well, except for the "clean" oil that manages to blow back there from my a bit leaky 2300 hour 0320. I would hate to see what the inside of the tube looks like running that far back. Thus far, no blockage. (crossing fingers)
Click to expand...

Jon,
My Dad took flying lessons from Frank Price when we lived in Waco. My earliest flying memories were riding with Frank in a Taylorcraft doing a slow roll while the fuel check cup in his palm never moved.
Frank practiced for his airshows in his Bucker (wings built by Jim Swick) and I had a ringside seat, at the age of three. It would permanently shape my life...:)
I would meet his best friend Jim Swick much later in life and Jim and I became friends and shared our fondness for the T-Craft design. It's 23012 airfoil is very similar to the RV's and shared by the Bonanza, Staggerwing, King Air and T-34.

Jim's final T-Craft was literally drawn up in front of me and scratch built using sawhorses, tape measure, tubing, a level and phenomenal welding. Truly a lost art. I heard he built his M-14P powered Bucker the same way which BTW was the most amazing Aerobatic airplane I have ever flown (F16 notwithstanding). For the "T-Coupe" Jim installed a Rotec Radial and his signature inverted oil system in a truly retro modern design aimed straight at the Sportsman category sport aerobatic pilot.
True pioneers, sorely missed...

V/R
Smokey


Last "Swick-T-Coupe"
 
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I signed off Jim's last "Swick T" in October of 2009.
Unfortunately, due to extenuating circumstances, it has still not flown.
 
It amazes me how a thread on oil separators can tie into connections to history, people, and thier airplanes. Aviation is a small world and this site is truly blessed with the many folks that have ties to amazing things.
 
anti splat air/oil separator installed

I don't have any performance numbers yet, as I just installed this today and have made one flight. I replaced my Airwolf Air/oil separator and added the Antisplat aero separator. As a DAR I have seen many of Allan's products on RV's and I have been really impressed, so I decided to try this one myself. It certainly is a lot less complex of an installation than the Airwolf, except for the required welding of the stub onto the exhaust system. As you can see in the photo, I did add a brace to the stub just to prevent any cracking of the exhaust pipe. It probably isn't necessary, but I'd rather have done it and not need it than to have to repair it later (like on a trip to Alaska).
I know there have been some posts related to increased HP, and I hope I get those same results, although I am not sure I will actually feel the difference since the 10 has a constant speed propeller and is already quite exhiliarating at takeoff. I currently have the oil set at 9 qts after a fresh change, so I will update here in the near future.
By the way, the kit was first class. All parts were of very high quality, and all required parts for a complete installation were there. No need to call Spruce. :) I like it!

Vic

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plehrke said:
It would be interesting to send a sample of what was in the seperator and a sample from the crankcase in for oil analysis. See the difference in level of contaminates. Maybe after 2 or three times, you shed some facts on the debate of returning oil to the crankcase.
Click to expand...

I would think with reasonably fresh oil you might not see much in the way of acids, etc., as the detergent additives in the oil would "mask" their presence.

Being that most are conservative with their oil change intervals, you might never get to a point where there would be a detrimental buildup of acids, etc.

No "science" was employed while composing this observation, just sounds reasonable to me!

mjb
 
Air oil separator update

I've got about 12 hours now on the Anti-Splat spearator that I mentioned in an earlier thread, including a couple of 3 1/2 hour legs. Not a lot of time, but some interesting things I thought I would share. I have over 600 hours on this RV-10 now, so I have a pretty good feel for it's performance and behavioral characteristics.
First, the ground idle has picked up about 50-70 rpms. So much so that I need to turn it down, but am not looking forward to pulling the cowling down again so soon, so that will wait for a while.
The belly is the cleanest I have ever seen it. Prior to this on a 7-8 hour trip there would be a little film of oil on the belly. Not so anymore. This might be due to the fact that we now have it draining into the exhaust, but it sure is nice!
Last, and certainly not scientific, so I am sure I will get eaten alive on this board, but I feel pretty confident I have picked up 1-2 knots in cruise. We make this particular trip to Ohio from Atlanta, up at 9K' and back at 8K' (not any higher this time of year due to temps and icing), and I normally see an indicated TAS of 168-169 knots. Once in a while it will touch 170, but not stay there. On the trip this week end it was always a solid 170-172 knots. Both ways. Two different days. Time will tell, but if the 7-8 HP claim of Allan's for the device is true, and the old "cube root of the HP increase yields the TAS difference in cruise" then the increase I am seeing seems right, as the cube root of 7-8 HP is somewhere between 1-2 knots.

As always, your mileage may very, but I am very happy. :)

Vic
 
Interesting!

Interesting finding and much the same on my 10 but the vacuum reading on the crankcase is not as low as advertised unless the reed valve is located in an exhaust header, see Dan Horton's posts.
http://www.vansairforce.com/community/showthread.php?t=92980&highlight=RV-10+oil+sep&page=7
Allan Neemo has you weld in the stub just where you have it and I am still hoping to hear from him on exactly how he achieved 5 or 6 inches of vacuum???
He is pretty quick on responses usually but has not responded so far.
Maybe someone can flush him out:rolleyes:
 
Hope This Helps Clairify!!!!!!!

N427EF said:
Interesting finding and much the same on my 10 but the vacuum reading on the crankcase is not as low as advertised unless the reed valve is located in an exhaust header, see Dan Horton's posts.
http://www.vansairforce.com/community/showthread.php?t=92980&highlight=RV-10+oil+sep&page=7
Allan Neemo has you weld in the stub just where you have it and I am still hoping to hear from him on exactly how he achieved 5 or 6 inches of vacuum???
He is pretty quick on responses usually but has not responded so far.
Maybe someone can flush him out:rolleyes:
Click to expand...

....Sorry to see you were awaiting a response and I was unaware of your question. I will try to answer a couple of questions in regards to the vacuum readings. First of all it is not possible to measure crankcase pressure or vacuum with a mechanical gauge as it can't begin to operate fast enough and only shows some sort of average less its own mechanical errors and limitations. We use a piezo crystal sensor to record the pressure waves on the dyno. The major portion of the pressure reduction is accomplished via the pumping action of the crankcase as it volume changes throughout the rotation of the engine. The valve allows air to exit but not enter, thus creating a pressure drop. The tube welded into the exhaust will supply only a minor part of the pressure reduction and mainly allows the vacuum to be created by the crankcase itself. The number of exhaust pressure pulses is not important and the valve can be installed in only one pipe on a four pipe exhaust system. When the engine is operating at 2500 RPM there are 1250 exhaust pulses per cyl and this is adequate to keep the valve open. It is important that the valve be installed in a vertical location (not leaning more than 45 deg.) as this will prevent puddling in the valve after shutdown of the engine. Second thing in discussion is the valve failing and what would happen. In the 33 years we have been using and marketing this valve we have never seen a failure with thousands sold and in use. But, hypothetically if one were to fail it would fail open only as it is a reed valve. This would create exactly the same condition as if you had no valve in line and would revert back to stock breathing. The only consequence would be a power loss in proportion the experienced gain. As for the valve sticking closed causing some damage, that is virtually an impossibility. This installation has a multitude of beneficial advantages with no negative effects and only serves to make the flying and maintenance of your engine less troublesome and add some efficiency and or performance to your flying. Thanks, Allan....:D
 
PerfTech said:
The major portion of the pressure reduction is accomplished via the pumping action of the crankcase as it volume changes throughout the rotation of the engine. The valve allows air to exit but not enter, thus creating a pressure drop.
Click to expand...

It's an opposed engine. There is no change in total crankcase volume through each complete revolution, only a change in the case volume under each opposed cylinder pair. As the case volumes are connected, one increases as the other decreases; they simply pump back and forth.
 
DanH said:
It's an opposed engine. There is no change in total crankcase volume through each complete revolution, only a change in the case volume under each opposed cylinder pair. As the case volumes are connected, one increases as the other decreases; they simply pump back and forth.
Click to expand...

....In theory that is correct, but if you do as we do and install a temporary gauge on the crankcase you will see that this is not the case. The pressure fluctuates considerably when the engine is running. If you crank your engine over with the starter (mags off) and place your hand over the breather you will feel the engine suck and blow on your hand as described. Try it! regards, Allan....:D
 
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