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Oil Consumption and Breather Tube

Dan H chided me for wishing this power gain in a previous thread.
He suggested the inside of a Lycoming engine wouldn't support the kind of internal airflow required.
So I got out my trusty educational core engine case. The front 2 cylinders live in a closed crankcase chamber, with a 2" per side triangular hole under the main bearing. all the oil drain back to the sump, plus all the crankcase blow-by must pass thru this hole.
Bear in mind the front 2 cylinder's pistons go out and in together, opposite of the rear pair.
So the front & back crankcase chambers are pressurized and de-pressurized opposite of each other during each crank rotation.
Flow must fluctuate thru that little hole, with a constant average flow going aft with the oil drain back to the pan + the blow by flow thru the rear chamber toward the crankcase vent.
My point is that you can't get fluctuation free 'Low Crankcase Pressure' like an auto engine with a common crankcase.
Crankcase compression is going to happen with this old fashioned design engine, the higher the RPM, the less effective pressure averaging can occur between chambers.
I believe Dan's conclusion, and now mine, is: Large power gains from V8 auto engine tests won't be attained.
 
Many or all race-teams disagree

... It isn't a question of airflow! It is a reduction of pressure and rareification of the trapped air in the crankcase.Ie;
.
http://www.dragzine.com/tech-stories/engine/tech-how-external-vacuum-pumps-free-up-horsepower/
.
http://www.butlerperformance.com/images/EvacPumpKit/evac.pdf
.
http://nutterracingengines.com/racing_oil_pumps/crankcase_vacuum_facts.html
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http://www.gzmotorsports.com/vacuum-pump-guide.html
.
http://www.dragstuff.com/techarticles/vacuum-pumps.html
.
http://www.carcraft.com/techarticles/ccrp_9903_moroso_vacuum_pump_test/
.
http://www.429-460.com/t13910-moros...il-pressure-ect-very-interesting-check-it-out
...A simple search rendered this; About 443,000 results
I find it hilarious and difficult to believe that the finest minds, associated with the biggest, most well equipped, best financed race-teams in all types of racing, are misinformed and a couple of people on this forum know all the answers. I have seen the results in our dyno-cells myself so I know for a fact this works. Thanks, Allan...:D
 
PerfTech said:
... It isn't a question of airflow! It is a reduction of pressure and rareification of the trapped air in the crankcase.Ie;

...A simple search rendered this; About 443,000 results
I find it hilarious and difficult to believe that the finest minds, associated with the biggest, most well equipped, best financed race-teams in all types of racing, are misinformed and a couple of people on this forum know all the answers. I have seen the results in our dyno-cells myself so I know for a fact this works. Thanks, Allan...:D
Click to expand...

I searched for "Stop Sign" and got 30,400,000 results.

Alan, share the data, maybe HP vs crankcase depression (vacuum) at a stabilized continuous power delivery condition. This would be like what we use at cruise or racing, and useful.

There is nothing wrong with saying it only gives us a clean engine and underside. That is valuable enough. Be Happy.

Anyway, the "piston pressure" is just bunk. The lower windage (flailing crank throws and connecting rods) with low density crankcase is very real. It should be known that this is but one of many sources of friction, and not very significant. Kinda like aerodynamic covers for fuel vents. Real, and small - - real small. I like them, they look cool.
 
BillL said:
I searched for "Stop Sign" and got 30,400,000 results.

Alan, share the data, maybe HP vs crankcase depression (vacuum) at a stabilized continuous power delivery condition. This would be like what we use at cruise or racing, and useful.

There is nothing wrong with saying it only gives us a clean engine and underside. That is valuable enough. Be Happy.

Anyway, the "piston pressure" is just bunk. The lower windage (flailing crank throws and connecting rods) with low density crankcase is very real. It should be known that this is but one of many sources of friction, and not very significant. Kinda like aerodynamic covers for fuel vents. Real, and small - - real small. I like them, they look cool.
Click to expand...

.... The links I posted were so anyone interested could research for themselves. It somehow seems a fruitless effort for me to post some of these things as they always fall under much scrutiny, as if I were trying to mislead or misrepresent for personal gain. I guess this is just the nature of this type of venue. The list of documented results, and the corresponding reasons for the gains are all available and are virtually endless. Some of the important ones as applied to our application are laid out and discussed extensively on these links I posted. Windage, reducing piston ring flutter, better piston ring sealing from increasing top to bottom differential pressures, Stopping oil consumption via end gaps on rings, stopping oil coking in exhaust guides due to migration with no valve seals, cutting oil contamination of fuel via intake valve guides, boiling off moisture in oil at a lower temperature, dramatically reducing oil vapors and stopping them from being lost overboard and deposited on the bottom of your aircraft, just to mention a few. These things are far from "bunk" and are well documented if one takes the time to look. Thanks, Allan:D
 
125gn6r.jpg
 
Installed 2....

RV-8A / have installed the AntisplatAero oil separator + 2 x the saddle mount type pipe on my IO-360 ( installed it on different exhaust pipes ). Don't feel comfortable to have just one installed, just in case something does not go as planned...have flown 10 hours now with this setup, belly is of course oil free. Whether there is any reduction in oil consumption or some increase in power is too early to say. Checked the tubes for build up after 10 hours, so far there is none. Whether there is an increase of power I should see finally at the fuel consumption. Am recording it since first flight, keeping the same power settings over time there should be a reduction in fuel consumption visible. Will see...

VansNet

VansNet

VansNet

https://picasaweb.google.com/102171...hkey=Gv1sRgCPaV0YekzorwNg#6066077246507971442
VansNet

VansNet
 
Replace Saddle Mount tube

Hi Allan,

Please also send me a replacement saddle mount with the inner-tube as well.

Thanks,

Jeff Barnes
9820 52nd St
Kenosha WI 53144
847-331-2567
 
ASA Air/Oil Separator with new Saddle Mount

Between the two of us pilots we have over 100 years of aviation maintenance experience. One of us is an A&P the other an IA.
After exploring this thread from the first post to the last and reading ALL the information that Allan at ASA provided on this thread; we installed the ASA Air/Oil Separator and Saddle Mount with Air valve on our RV6, 160 HP Lycoming & constant speed prop.
This engine had had a history of creating "the greasy belly syndrome"...!!!
It would use about a quart of oil every 8 hours of flight; usually running it at 6 quarts for local flights and 7 quarts on cross country.
We have installed the ASA Air/Oil Separator and ASA's new Saddle Mount Air valve. The Air valve is mounted on the Right Exhaust Stack 12" from the tip outlet.
We also installed a second check valve (NAPA P/N: 2-29000) in the hose between the Separator and the Saddle Mount Valve; to preclude any issues with the exhaust saddle mount orifice getting plugged up with carbon..
We have added into our maintenance checklist; to remove the saddle mount at every oil/filter change to inspect/clean any carbon accumulation and test the check valves for proper operation.
The bottom line is that after 10 flight hours, two of which were 3 hours in duration and 10,000 AGL. THE OIL CONSUMPTION IS ALMOST ZERO AND THE BELLY IS CLEAN.
I can send pictures of the installation to anyone who wants them.
 
images.jpg


"But Joe (or Dan or Bill or Scott or Allan ;)), I want it all to be true?clean belly and more power?I tell ya...is that too much to ask?"

So this "Bill Gannon" rearranged the plumbing, and now the relief (backup) valve comes off the side of the tee, as Dan suggested (good call). Continued investigation of the oil drips located a seep from within the oil cooler. New oil cooler aboard, test flight good, and off to the Watsonville Airshow. 7 flights (6.6 hrs) later, and peering up in the cowl exit shows no oil, with a cleaner belly than after recent hops (some smoke oil residue, of course). Had the oil up to 9, and did use some, which has been true above 7-8 (of 12). Will see how this continues before the next oil change, and will see how the CVV tube looks at that time.

HP claims are enticing, and the idea of less belly shmear, with a tad of HP is something I didn't want to leave on the table?just in case?ya know, with those Wascally Wockets to chase around! ;)

Cheers,
Bob
 
clean belly

Oil change yesterday at 55 hours. Covered oil filter with zip lock bag. Undiscovered Hole in zip lock bag made same mess as last time... without zip lock bag.
Drained all hot oil... took sample for analysis. Removed clamps on saddle fitting from Antisplat Aero. Inspected the double wall tubing and found no residue. Installed same back on the Vetterman's. Safety wired new filter. Forgot to attach scat tubing to lower cowl inlet. Flight test and leak check ok, but discovered scat loose on post landing inspection.
Clamped it back on and reduced the engine smells that were emanating from the air vent. Went to Sedona for a Buffalo Burger instead of cleaning the belly.
Good day all around.
 
How many people chasing the "clean belly" also have a smoke system?

With a full christen inverted oil system I have a spotlessly clean belly.


Until I go "smoke on" :D
 
RE: Chasing the "clean belly" with ASA air/oil separator & saddle mount.

The "clean belly" is just icing on the cake.
The real deal is the significant reduction in oil consumption...
 
Tha's what I thought

he "clean belly" is just icing on the cake.
The real deal is the significant reduction in oil consumption...
Click to expand...

After the 3rd oil change since installing the Air/oil separator it appears that oil consumption has decreased very slightly. Although I somehow wanted to see the big improvement initially, I cannot measure a significant change in oil consumption.
The way I precisely measure consumption is by counting all the oil in and
measuring all the oil that comes out at oil change plus anything added between changes usually one quart keeping oil level between 8 and 9qts.

So for me it's the clean belly and an absolutely clean engine compartment
without any leaks or seeps from anywhere.
I have measured negative crankcase pressure and I have installed a second reed valve.
The exhaust stub does coke up over time but with a second reed valve installed I feel comfortable keeping the breather tube connected to the exhaust
reed valve.
Clean out the stub every other oil change works for me and to double check I stick a bore scope up the tailpipe a couple of times between oil changes.
 
Yes, thanks for posting the link to my crankshaft seal blowout thread. I was about to do the same thing.

I was not aware of the excellent discussion in this thread, mainly because the thread title is undescriptive of the important subject matter, so I skipped it--luckily I lived to tell about it!
 
Gash said:
Yes, thanks for posting the link to my crankshaft seal blowout thread. I was about to do the same thing.

I was not aware of the excellent discussion in this thread, mainly because the thread title is undescriptive of the important subject matter, so I skipped it--luckily I lived to tell about it!
Click to expand...

Didn't mean to steal your thunder.

Good job on a safe landing and getting the word out.

Is the engine OK after operation with the reduced oil levels for a short time or do you need to tear it down and see?
 
NTex said:
Didn't mean to steal your thunder.

Good job on a safe landing and getting the word out.

Is the engine OK after operation with the reduced oil levels for a short time or do you need to tear it down and see?
Click to expand...

You didn't steal any thunder. The only thunder I ever have is chili related. And yes, the engine is just fine. Thank you for asking. It still had 3 quarts of oil in it when I shut down. At the rate it was coming out, I figure I still had a good 6 minutes left before it ran out of oil. I took it out the next day after the repair and beat up the pattern on a test flight. Everything is running fine and back to normal.
 
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How much vacuum?

After reading several articles about the benefits of pulling some vacuum on the engines, I am really surprised someone has not installed a simple vacuum gauge to measure how much vacuum is being created with the Anti Splat system.

It only takes a very small leak somewhere on the engine to negate any vacuum that the exhaust based system can generate. If there are inconsistent results it may well be that those who don't see much benefit are not actually getting any vacuum due to some small leak.

Somebody needs to step up and measure the vacuum or pressure before and after an install, or simply measure after, then disconnect and see the difference.

To get results there needs to me some vacuum.

From my reading of the articles, it is obvious that the exhaust based systems do not generate enough vacuum to get the best results and most have gone to the use of external pumps and often times a vacuum relief valve is also used.

I would think that measuring the vacuum in the crankcase should be part of the system check after it has been installed. Why not?

I think we are looking for a small amount of vacuum here, maybe 4" of Hg? The articles talk of running vacuums as high as 15" Hg but they are running external pumps and very tight engines compared to our aircraft engines.

An aviation engine may need a system that can move quite a bit of air to achieve good results when compared to an auto engine because of how "loose" our engines have to be.

So a few questions for Allen:

1. Did you measure vacuums as you developed the product? If so, how much vacuum was being created?

2. Do you think that some engines may need to "double up" with a second saddle setup to get enough vacuum?

Randall
 
Still waiting for delivery of my manometer (31 days?slow boat, eh!). Will report case vacuum test results when I git 'em! Have the second (relief) valve installed as well.

Cheers,
Bob
 
I'm with Vic. The backup relief valves just a crutch. It's not a matter of if it's going to clog up, it's when. So the backup valve is really the main breather. Mine was 90% clogged in less than 100 hrs. I will agree that it does reduce oil consumption by a slight amount, and it does keep the belly clean. But... The downside is far to great a price to pay as Gash demonstrated for us.
I have removed the exhaust tap, welded on a patch over the hole and vented the AO sep over the exhaust. Cleaning the belly every 25 hours is a good opportunity to inspect the plane.
 
It is not just RV's

NTex said:
I was just unaware of a required maintenance interval for this setup.
Click to expand...
The Cirrus Turbo Normalized (TN) model does almost exactly the same thing. It ports the breather into the left tailpipe (without a valve) via a tube welded into the pipe. Owners love it because the belly is clean. But obviously if you dump any oil at all into that environment it will coke up and even gets looking like an icicle.

The AMM says to clean the coking out at every oil change. I have found some nearly closed that obviously were not maintained per the AMM. Many mechanics have a tool they use, some use a radiator hook, some just a long metal rod with a nail like arm welded out 90 degrees. Hook it and scrub around and the blockage is gone. In this case it is welded far enough aft in the tailpipe (and it is pretty large diameter pipe) that it is not much of a reach in. Just FYI, even production planes have this feature and issue.
 
Data

Just did my third oil change since installing the ASA air separator with the check valve plumbed into the right exhaust. I have installed the relief valve per Dan H.

At all three oil changes the tube welded into the exhaust was approximately 30% occluded with gummy black stuff. I removed and cleaned each time. Doesn't look like the relief valve has opened at all.

I run between 7 and 8 quarts, IO-540. Belly has been completely clean and the one small oil seep I had has completely dried up. Oil consumption doesn't seem to have changed although there really isn't enough data for a trend as yet.
 
Hi all, just a quick question regarding ASA valve mount. I got mine without notice in the pack so checked on the web for valve set-up.

I found a page from Jason Beaver blog :
http://www.jasonbeaver.com/rv7/2013/07/installed-anti-splat-aero-oil.html

stating : "The vacuum valve mounts on the exhaust pipe like this. The slight angle pressurizes the line so that only higher pressure from the crankcase will push gases into the exhaust pipe. This has a reed valve inside that only allows flow from the crankcase into the exhaust pipe and not the other way."

IMG_0871.JPG



TBH, i was about to install it in the other direction :confused:

Thanks
 
It appears from the photo that the valve is being mounted improperly. The purpose of mounting it at an angle is so that you create a vacuum in the crankcase, not pressure!
 
orionis said:
TBH, i was about to install it in the other direction confused
Click to expand...

In the photo, the exit end of the tailpipe appears to be on the left. If so, you are mounting the tap backwards. Turn it 180 degrees.

In addition, note that taps mounted on the tailpipe appear to build internal deposits more quickly than taps mounted closer to the cylinder. Some RV-10 installations have clogged the tap tube in 30 hours or less. Please be sure that you install a second reed valve as a pressure release safety valve. See previous posts for photos, or contact Anti-Splat immediately.

Some of us hold the personal opinion that the particular silver-colored valve in the photo (brand/manufacturer unknown) is of poor quality. See previous posts in this thread documenting failures.
 
This makes sense.

I hope to be the only guy that get the product without notice. Because this wrong information is the one you get first when you type "antisplat valve rv7"

Should be very useful that ASA put these notices in a download section..
 
orionis said:
Hi all, just a quick question regarding ASA valve mount. I got mine without notice in the pack so checked on the web for valve set-up.

I found a page from Jason Beaver blog :
http://www.jasonbeaver.com/rv7/2013/07/installed-anti-splat-aero-oil.html

stating : "The vacuum valve mounts on the exhaust pipe like this. The slight angle pressurizes the line so that only higher pressure from the crankcase will push gases into the exhaust pipe. This has a reed valve inside that only allows flow from the crankcase into the exhaust pipe and not the other way."

IMG_0871.JPG



TBH, i was about to install it in the other direction :confused:

Thanks
Click to expand...

... This is backwards, rotate 180 deg. Sorry your paperwork didn't get included with your order. I will e-mail you a copy today. Thanks, Allan...:eek:
 
PerfTech said:
... This is backwards, rotate 180 deg. Sorry your paperwork didn't get included with your order. I will e-mail you a copy today.
Click to expand...
Might want to email Jason Beaver through his website and let him know that his is backwards too...
 
I have a o-360 with the anti-splat oil separator and it still want to in the 6-7 qt. range. 1200 hrs on engine and can't hold 8 qt. for an hour.
 
The air oil separator returns oil but it also returns all sorts of other **** that you don't want circulating through your engine. The Skyranch Engineering book claims that using an air oil separator and plumbing back to the sump is like taking a plastic tube and sticking one end in your rear and the other in your mouth! Sorry if any of you are eating lunch :eek:

On my little O200 I run a separator because I was fed up with cleaning the airplane. I trap the liquid in it and empty it after every flight.
 
sblack said:
The air oil separator returns oil but it also returns all sorts of other **** that you don't want circulating through your engine.
Click to expand...

(1) Oil analysis says otherwise, and (2) there's a simple explanation for catch can snot if you think about it.
 
Agreed Dan. My oil analysis comes back with no abnormal measurements after 280 hours using the oil separator.
 
I knew I should have updated that blog entry :). I mistakenly installed the valve backward last year and received a nice email from someone following my site about it. I fixed it long before first flight:

IMG_1183.JPG


Sorry for any confusion this caused; I've updated the blog entry now to indicate that this was in error.

This is exactly the kind of thing that makes building in a very public way so valuable; people spot mistakes and point them out to each other. We're all safer by keeping an eye on each other's work.
 
... Very nice of you to post this to help others if confused. This is one of the up-sides to the forums and is very valuable to us all. I would like to add that you did a beautiful job of documenting and installing the unit both directions. Thanks, Allan....:rolleyes::D
 
Oil on the belly

I never could understand why the general rule is to run with the oil tanks half full because these antiquated engine don't come with an oil recovery system.
Would you run your car with half the oil it calls for?

I have an antisplat oil seperator and I now run full at 8 liters and it doesn't end up on the belly.

These engines are built so loose that we accept 1 liter per 10 hrs as good consumption.

My car runs for 100 hrs between changes and it will be down half a liter,,,and that is probably due to evaporation.

Ray
 
raytoews said:
I never could understand why the general rule is to run with the oil tanks half full because these antiquated engine don't come with an oil recovery system.
Would you run your car with half the oil it calls for?

< snip>
Ray
Click to expand...

This is just not a valid comparison. The FAA requires the oil sump hold enough oil to use all the fuel at the highest acceptable oil consumption rate specified by the engine manufacturer (BSOC). They don't care if the high oil level actually causes a higher burn rate for a while, it is a trade off.

Easy to test this yourself. Measure/record the oil usage vs sump level. Record qt/hr for full, -1 Qt, -2 qt etc. Get three measurements for each level just to be sure. Then using this data, you can satisfy yourself as to why the general rule might have been created, and show off your data to others in the future. Half might be too low, maybe it is different for your engine and operation profile. :D

edit: Ref AC 23-16a see this doc for all the details.
 
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swordtail said:
I have a o-360 with the anti-splat oil separator and it still want to in the 6-7 qt. range. 1200 hrs on engine and can't hold 8 qt. for an hour.
Click to expand...

This is normal for Lycoming engines. My Cherokee 140 with an O-320 will keep no more than 6.5 qts. I add a quart when it gets below 5.5.
 
Just another data point. I still have the vacuum system in place, though I intend to remove it when I go full inverted systems (after Oshkosh). I recently flew from Denver to the Florida keys and spent a week flying around Florida. 25 hours of flight time total. Here is a pic of the vacuum tube following the flight.

D472D011-A077-484C-A301-DAA73C3E31AA_zpslt6o42ih.jpg


I don't know why some installs are coking up and others are not. Perhaps it is how the planes are flown, perhaps it's the oil used, condition of the engine....I have no idea but as you can see, mine shows just about zero buildup in the 25 hours of flight, many of which were long legs (9.5 hr day returning into headwinds). I do still treat this as an untested experimental setup sold with zero pre-testing and questionable engineering....meaning I look at it often. I also scrapped the valve Alan sent and used a Napa.
 
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Thanks for the pic. Please tell us how you run your engine. LOP? ROP? What kind of EGT are you seeing typically on that exhaust pipe while in cruise? How many inches from the end of the pipe did you install the stem? What type of oil do you use, and finally, what engine are you running? Thanks for much for adding to the data collection! :)
 
Gash said:
Thanks for the pic. Please tell us how you run your engine. LOP? ROP? What kind of EGT are you seeing typically on that exhaust pipe while in cruise? How many inches from the end of the pipe did you install the stem? What type of oil do you use, and finally, what engine are you running? Thanks for much for adding to the data collection! :)
Click to expand...

Additional question - - how long from start to shutdown - especially in cold weather. The theory under thought is water laden blowby, where several cycles have not evaporated all the collected moisture from the oil. Then the condensed water in the cold pipe collects and carries oil to the evaporation/collection point, then with time it hardens and restricts. Just a hypothesis separate from steady state conditions.
 
Gash said:
Thanks for the pic. Please tell us how you run your engine. LOP? ROP? What kind of EGT are you seeing typically on that exhaust pipe while in cruise? How many inches from the end of the pipe did you install the stem? What type of oil do you use, and finally, what engine are you running? Thanks for much for adding to the data collection! :)
Click to expand...

I operate almost exclusively at 100 ROP.
EGT's typically between 1200 and 1275 in cruise
Vacuum tap is 13 inches from #4 flange. Closer to the heat than some have installed theirs I think. Vetterman 4 pipe system
I use Aeroshell W80 plus in winter W100 plus in summer
Engine is Angle Valve 360, 10:1 pistons, dual Pmags, Superior cold air sump

As for how I operate the engine.... I seldom fly for less than 45 minutes winter or summer, and oil temps always over 170 (using shudder in winter). Throttle spends far more time full forward than in any other position, RPMs between 2300 and 2600 depending on my mood and how quickly I want to be there. Gentlemen aerobatics are common. Down in Florida I did find I seldom had the throttle full forward because I was always flirting with over speed. Sea level...what a beast she is down there. When going below 5000 here at home requires a shovel...no such issues....shove it forward.

I hope that helps some of the brighter minds figure out why some systems coke up while others do not. I have found traces of coking during previous checks but never more than is seen in the picture I posted previously. I will keep checking though.

Alan, have you considered a coating for the inside of these pipes? Something more difficult to stick to?
 
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I hope that helps some of the brighter minds figure out why some systems coke up while others do not. I have found traces of coking during previous checks but never more than is seen in the picture I posted previously. I will keep checking though.

Alan, have you considered a coating for the inside of these pipes? Something more difficult to stick to?
Click to expand...

.... Every time we were contacted by someone that had above average coking of their unit we would ask them to participate in our testing program. We sent out for testing an array of different designs and variations. We did try some tubing that had a coating similar to that found on frying pans Etc. Some with longer, shorter, different diameters, vented for cooling, an insulator gasket between the saddle and exhaust pipe and a few others. Now that we have gathered a considerable amount of information, with lots of hours on each design change, and having spent many hours poring over the collected data, I can finely report our findings. The one thing we saw consistently was this, the aircraft with the highest oil consumption seemed to have the worst accumulations. We did see minor changes with the different designs and mounting locations, but nothing dramatic, and definitely not a significantly different result. Unfortunately we weren't successful in finding a 100% cure and we will continue our testing program. We did learn one thing for sure, if the tube into the exhaust is checked / cleaned at oil changes you should never have a problem. We also have available on our website an inexpensive, easily installed, small safety bypass kit (we recommend installing this on all vacuum systems) that eliminates any and all possibility of a problem from coking, a failed valve or any breather restriction problems. In defense of these vacuum systems, we must add that the coking has occurred on a vary small number, (a fraction of 1%) considering the quantity (several thousand) in service. Thanks, Allan
 
FYI...I've been running Allens oil separator in conjunction with a Napa 2-29000 valve for about 1.5 years and a 150hrs. I inspect at oil changes and never had any build up....until this year. There was coked oil, but still had a 1/8" or so hole. Also, I don't have a overpressure relief valve installed. BUT........

I pulled the valve and blew thru it like always and this time it seemed to have some resistance. I wondered if it was my imagination or just memory loss. Anyway I talked with Stephen C about his set-up. He said why bother worrying, $18 bucks put a new one on.

Got 2 new ones and they are much easier to pass air through. My old valve was getting stiff and reluctant to move. So new valve and added the over pressure relief valve like many others have done.

so this years Condition Inspection Lesson: Just because things have been working good, they still need some thinking to ensure they stay good.
 
I would never run the valve into the exhaust without a bypass safety valve. It's just not worth the downside. We have had two reports of blown front seals resulting in inflight emergencies. I had the valve installed and after 50 hours it was 75% blocked. It's now back to just venting on the belly. My oil consumption is a quart every 18 hours.
 
Bill.Peyton said:
I would never run the valve into the exhaust without a bypass safety valve. It's just not worth the downside. We have had two reports of blown front seals resulting in inflight emergencies. I had the valve installed and after 50 hours it was 75% blocked. It's now back to just venting on the belly. My oil consumption is a quart every 18 hours.
Click to expand...

Yes, Bill, and people should not let the 1% failure fool them. It will coke, it truly is just a matter of time if left unattended. Proper maintenance should eliminate nearly all possibility.

50% of RVers fly less than 100 hrs/yr according to those who answered the survey.
 
Have I done something stupid.... for a long time?

Edit...
Thanks Bill.... looking closely at the slant cut tube... it appears it is facing correctly.
Still searching for my extra horsepower... have yet to find it.
 
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The slash cut opening is should be facing towards the rear of the aircraft to create lower pressure. See post 21
 
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