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  #71  
Old 10-28-2014, 12:37 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by N15JB View Post
Because my welder of choice was not available for a while, I elected to omit the valve temporarily, and installed the drain hose just above the right exhaust pipe.
The drain hose (1/4" nominal line) or the separator outflow hose (5/8" or 3/4" line)?

I'm guessing the 1/4" drain hose was plumbed to return separated oil to the crankcase, and you ran the large separator outflow hose to a position above the exhaust pipe.

Not that it matters. If you didn't pull a vacuum on the crankcase, how could the system be expected to slow your crankcase leak?

Given the situation, you won't like the Airwolf separator. As Vic noted, it taps upper plenum pressure (or vacuum pump outflow, if equipped), and actually pressurizes the crankcase. Typical crankcase pressure with a stock breather is less than 5" H20, with 1" being typical. The Airwolf system will result in a typical case pressure of 10"~15" H20 in cruise, more when you shove the nose down. Your leaks will get worse.

The above should not be taken as a endorsement of AntiSplat, nor as criticism of Airwolf. It is just an attempt at illustrating operating principles.

Quote:
Originally Posted by vic syracuse View Post
Gash, I hear you but respectfully disagree with the statement that we KNOW if it is properly maintained it will work.
Vic, Although I fully agree with the basic objection (we really don't know how long it might take to clog any given exhaust tap, as we don't yet fully understand the mechanism), I'd suggest that the installation of a relief valve greatly reduces the risk. Karl has done so.

Quote:
Originally Posted by Gash View Post
Allan explained that he actually did previously send out a bulletin to all of his customers who bought the oil separator and vacuum valve. In fact, he spent considerable effort and expense on the mailings, so it was a serious undertaking on his part.
Quote:
Originally Posted by ColoRv View Post
Did anyone in here receive a mailing from Antisplat warning of this possibility? I know I didn't.
I'd wager it to be a very rare document.
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Last edited by DanH : 10-28-2014 at 12:56 PM.
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  #72  
Old 10-28-2014, 01:45 PM
N15JB N15JB is offline
 
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[quote=DanH;928616]The drain hose (1/4" nominal line) or the separator outflow hose (5/8" or 3/4" line)?

I'm guessing the 1/4" drain hose was plumbed to return separated oil to the crankcase, and you ran the large separator outflow hose to a position above the exhaust pipe.

You are correct; 1/4" hose to the case, and 3/4" hose to above the exhaust.

Not that it matters. If you didn't pull a vacuum on the crankcase, how could the system be expected to slow your crankcase leak?

I did not expect the system, without the valve, to decrease my leak. I was surprised that the leak increased.

Jim Berry
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  #73  
Old 10-28-2014, 02:38 PM
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Bubblehead Bubblehead is offline
 
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Gash - thank you for the elaboration in Post #47. All good reasons for the choices made and proven out by the outcome. Great job and thank you for sharing it all with us.
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  #74  
Old 10-28-2014, 03:34 PM
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JonJay JonJay is offline
 
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Quote:
Originally Posted by ColoRv View Post
Did anyone in here recieve a mailing from Antisplat warning of this possibility? I know I didnt. But, thankfully....I do read far to much of these forums and knew of the danger. Still, for Alan to expect that every pilot would read these forums AND this thread which isn't titled to get the proper attention is foolish. I've said before and I'll say again, Alan is a great guy.... who will end up penniless if he doesn't stop putting out aircraft parts that aren't properly engineered and tested. Like Dynon's unforgivable delay in the freezing pitot tube fiasco....Alan shouldn't be sleeping until this is fixed or recalled.

With that said....the valve is still in mine, even though I did find more than a little build up of carbon in my saddle tube.
No. I did not receive a letter.
I bought one of these units. Due to the location of my brake reservoir and battery, I could not put it where their instructions stated. (Nothing about maintenance in the instructions by the way).
When I called the factory to ask for a preferred alternate location, I was told "that is what we recommend, but, put it wherever you like, its your airplane." That ended the conversation.
It's for sale. Separator and valve kit. New, in the box, never installed, nor will it ever be on my airplane.....
I was going to sell it, but did not feel comfortable doing so. Same reason I never sold my Blue Mountain stuff, which I gave it to Stein so he could help others.
PM me an offer. At least I will know that you know what you are getting.....
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  #75  
Old 10-28-2014, 04:29 PM
woxofswa woxofswa is offline
 
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Vic,

Don't sugar coat it ... Tell us how you really feel!

I think such direct talk is good all around.

This thread is the first time I've heard of fwd seal retention plates which initially sounded like a great idea. Then I started wondering why they weren't standard. Then I started wondering if there was a pressure build up and the front seal had retention plates where else might fail? Anyone know? The thrust seal may just be preferred to other potential options.

According to Alan Barrett, if we knew what was in the blow by we wouldn't return it into circulation, but that's his (learned) opinion. My open mind is starting to close.
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  #76  
Old 10-28-2014, 05:16 PM
Bavafa Bavafa is offline
 
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Quote:
Originally Posted by woxofswa View Post
Vic,

This thread is the first time I've heard of fwd seal retention plates which initially sounded like a great idea. Then I started wondering why they weren't standard. Then I started wondering if there was a pressure build up and the front seal had retention plates where else might fail? Anyone know? The thrust seal may just be preferred to other potential options.

According to Alan Barrett, if we knew what was in the blow by we wouldn't return it into circulation, but that's his (learned) opinion. My open mind is starting to close.
On that note; I wonder why there isn't a built-in pressure valve into the top of the deep stick. It would certainly not hard to make it and regardless of separator or not, it would possibly save some disaster.

Vic,
I am glad you are you raising the concern. I can't think of any other motive other than a healthy concern for others.
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  #77  
Old 10-28-2014, 05:35 PM
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akarmy akarmy is offline
 
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Default another option

I've been trying to stay out of this, but here's my input. I've been watching all of these threads for months as I was doing my FWF. When I started I was going to put in the separator, but as the failures started adding up, I followed Ironflight's setup in his RV-3 with the Half-Raven tank hooked up to the breather. The breather is open out of the tank and vents onto the exhaust. In the 40 hours of flying I just did, the belly is clean even after multiple zero and negative G maneuvers. I've seen a few references to it on other threads, but it never seems to get much air time. Not sure why.

Ok, ya it's twice the cost of the other separator, but it's larger and works great, and in the grand scheme of things its not that much money.

http://www.ravenaircraft.com/cat_engine.html

RV-8 FWF by akarmy, on Flickr
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  #78  
Old 10-28-2014, 06:19 PM
131RB 131RB is offline
 
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I have tried to stay out of this one but its time to speak up. First of all I agree with Vic 100 percent. I would be one of the old timers that Paul Dye refers to. We tried almost the exact set up into the exhaust system with a PVC valve that anti splat is using many years ago with the same problems that are ongoing today. I had a partial failure of a crankshaft seal failure over the middle of nowhere Texas many years ago. No where near what Gash had but a failure none the less. I found the PVC valve itself to be the culprit with the valve having glued its self shut. We all eventually went back to venting the outlet from the exhaust back to overboard or over the exhaust pipe.
Alan was warned of this by a prominent figure in this group and failed to listen. I do believe that the Anti Splat air oil separator is a fine unit by its self. However there is no way to gage when a when a failure will occur with the valve or the coking at the exhaust port. Every engine is different Do your selves a favor and find a safer way before someone gets hurt. Enough said.
Ryan
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  #79  
Old 10-28-2014, 07:02 PM
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Gash Gash is offline
 
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Quote:
Do your selves a favor and find a safer way...
All valid points Ryan, thank you. What are your thoughts about installation of a relief valve as previously described? It seems to me that this is a very acceptable risk mitigation. Combine this with regular service intervals, and I believe the equipment becomes a safe system. I would be interested to read comments from others on this combination of risk control measures.
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Last edited by Gash : 10-28-2014 at 07:04 PM.
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  #80  
Old 10-28-2014, 07:15 PM
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Walt Walt is offline
 
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Risk vs Benefit

Benefit = cleaner belly
Risk = engine failure

Let see, which one should I choose, this is a tough one
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