X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4472484 for flyrotary@lancaironline.net; Sun, 19 Sep 2010 10:41:15 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=alventures@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao106.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100919144039.ZUW3042.fed1rmmtao106.cox.net@fed1rmimpo01.cox.net> for ; Sun, 19 Sep 2010 10:40:39 -0400 Received: from BigAl ([72.199.216.236]) by fed1rmimpo01.cox.net with bizsmtp id 8egf1f00356cS2o03egfLP; Sun, 19 Sep 2010 10:40:39 -0400 X-VR-Score: 0.00 X-Authority-Analysis: v=1.1 cv=PyPhBskYoaHflNqPyNkGzxEHMB/j16Lz16eTzQWlCdI= c=1 sm=1 a=lN8H/RjlhkCyIsyuOn2r7w==:17 a=Ia-xEzejAAAA:8 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=CjxXgO3LAAAA:8 a=3oc9M9_CAAAA:8 a=pGLkceISAAAA:8 a=qQ9JC1rbBJEz2TBVxWMA:9 a=sGlvVwh32kxnUlC9IOYA:7 a=7LD5AAsmjwOneTlYDvbDIPj7AAwA:4 a=CjuIK1q_8ugA:10 a=EzXvWhQp4_cA:10 a=rC2wZJ5BpNYA:10 a=U8Ie8EnqySEA:10 a=MSl-tDqOz04A:10 a=4bghyuZEWWUt2Eip:21 a=M6Wcm8bvpIH4w9SA:21 a=E93lBu2AAAAA:8 a=lLdlVFmYpjsASQWeDcwA:9 a=ZVMuDI0Qyk739iH7_WEA:7 a=ga2lXOTCvRvgCWPfn2GMp8mBFMgA:4 a=hO30gm18fF0A:10 a=MpuOTR30KwMA:10 a=x6VBWS02HY8A:10 a=d1n8sfsg-lQA:10 a=NWVoK91CQyQA:10 a=AAuAI4gn_zumN44_:21 a=FfX5DNLUPihiP1G-:21 a=lN8H/RjlhkCyIsyuOn2r7w==:117 X-CM-Score: 0.00 Authentication-Results: cox.net; none From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: psru oil seal Date: Sun, 19 Sep 2010 07:40:51 -0800 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0000_01CB57CD.FBDEB5A0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6863 Importance: Normal Thread-Index: ActX/UNwnz2ZqIfOT8CexDybOlg3iQADgKEg In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 This is a multi-part message in MIME format. ------=_NextPart_000_0000_01CB57CD.FBDEB5A0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Mark; =20 I'm very pleased to hear it happened while still at the airport. =20 There should be little or no pressure forcing it out; and there should = be no significant level of oil in the housing, so it is just the 'splash' = around the shaft. Given the large quantity of oil you lost in a short time = would suggest significant pressure and a backup of oil. Do you have at least a 3/8" line for the drain-back, and could there be some restriction? =20 =20 You also might want check what kind/brand of seal you're using. I had an issue with that mounting plate seal on my 20B after about the first 50 hours. It worked part way out of it's socket (I guess it was against the damper plate hub) and resulted in some minor leakage. I had Tracy send = me a new seal, which I didn't like because; IIRC, the outer part of the seal = did not have the coated metal flange, just hard elastomer material. I felt = that after running hot for awhile it could loosen and not stay in place. = Tracy gave me brand and part number and I got a replacement to match the = original. Unfortunately, I can't tell you brand and part#; although may still have = the box and old seal at the hangar. =20 Also don't know what I did to insure it stay in place. May have just = coated it with hardening gasket maker, or peened a couple of dents at the edge = of the hole in the plate. In any case, it has remained where it belongs for = the last 150 hours. =20 =20 Al =20 =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Sunday, September 19, 2010 5:19 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Check PSRU Oil Drain-back hose was Re: Watch = that psru oil seal =20 Ed, =20 You and Lynn may have hit on something regarding the crankcase vent line being too small. It may have been marginally acceptable with the side = port engine, but way undersized for the fire-breathing p-port. First time I = ran it real hard, out came the seal. I am using the stock vent line, but = will go ahead and up-size it while I'm fixing the psru seal. =20 =20 Mark On Sun, Sep 19, 2010 at 8:10 AM, Ed Anderson wrote: Mark, here's another thing to check for - the oil drain back hose from = the PSRU =20 The PSRU typically has its oil drain-back to the oil pan which can be "pressurized" by blow-by of the rotors. This back pressure could = impede the flow back of oil from the PSRU because by the time the oil in the = PSRU is ready to drain back it has dropped the oil pressure from its 80 psi = input to practically zero. So it basically gravity feed back to the oil pan. = I guess the oil pan pressure could get to the point of serioulsy impeding = the oil blow - but I would think that much crank case pressure would have = given other indications - such as blowing your dip stick out {:>) =20 Now if the PSRU oil drain-back became plugged/restricted/crimped for = some reason then the pressure on the seal might eventually reach near the 80 = psi input mark and that would put considerably force on the seal. So (as I = know you already planned) check out the drain back hose. =20 But, in any case mechanically restraining the seal sounds like a smart = ideal in any case =20 Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com From: Ben Schneider=20 Sent: Sunday, September 19, 2010 8:39 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Watch that psru oil seal =20 Lynn,=20 =20 Am I reading you right in saying that it it was crankcase pressure, = not oil pressure. And to relieve said pressure, one needs a larger relief = tube than the factory one on the oil fill. (call it perhaps 3/16" without = going to the hanger and measuring) =20 Ben --- On Sun, 9/19/10, Lehanover@aol.com wrote: From: Lehanover@aol.com Subject: [FlyRotary] Re: Watch that psru oil seal To: "Rotary motors in aircraft" Date: Sunday, September 19, 2010, 7:14 AM In a message dated 9/19/2010 5:41:35 A.M. Eastern Standard Time, msteitle@gmail.com writes: Kelly, =20 =20 My custom adapter plate was built on a Bridgeport mill. The hole = spacing (and sizes) were obtained from a drawing for the actual RD-2C plate. = Could it be a thou or two oversize? I guess that's possible, but I don't = think so. The machinist that did the work is very meticulous. However, = before reassembly, I'll definitely check it to be sure. The bottom line is = that there is 90-100 psi trying to push it out of place. So, I feel that a mechanical fastener is the only real way to guarantee that it stays put = 100% of the time. =20 =20 Mark Anything not positively retained in aircraft, will eventually fall off. Garlock style lip seals will just barely hold back oil splash with = little to no pressure. You see Garlocks pressed into cavities that are cast or = formed with retaining lips at the end. Not into smooth bores. More than a few pounds against a lip seal over heats the seal and fails the lip allowing = a leak. Note the oil drainback paths in the rotary, so seals see no = pressure even beside a main bearing other than from crank case gasses..=20 =20 I had a weaver Brothers three section dry sump pump that had the = pressure section in the blind end of a casting so no high pressurized oil was = exposed to a seal of any kind. The drive shaft extended from the scavenge pump = end, so any pressure pulses would of minimal size against the Garlock seal pressed into a smooth bore in the end plate. Each session the seal would = be found dancing along the shaft with oil dripping off of everything. A competitor told me to retain the seal with a plate of some kind. Once = that very long weekend was over I did that with a plate and three little = screws. I replaced the single lip seal with 2 half width lip seals and the plate = and never had another problem. I also cut a tiny groove from the suction = side of the pump to the center of the shaft cavity. Oil drain-back to a lower pressure area.=20 =20 Lip seals are the most freedom loving seals of all. If pressurized they = turn their lips inside out and leak on you. =20 If you persist, they will escape the bore and dump your oil out on the ground. They have been that way since the first day. Thought should be expended on the release of crank case gasses. The street engine has a = tiny tube sticking out of the oil filler neck. This is way too small for operation above about 3500 RPM.=20 =20 Lynn E. Hanover =20 ------=_NextPart_000_0000_01CB57CD.FBDEB5A0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Mark;

 

I’m very pleased to hear it happened while still at the airport.

 

There should be little or no = pressure forcing it out; and there should be no significant level of oil in the = housing, so it is just the ‘splash’ around the shaft. Given the large quantity of oil you lost in a short time would suggest significant = pressure and a backup of oil. Do you have at least a 3/8” line for the = drain-back, and could there be some restriction? 

 

You also might want check what = kind/brand of seal you’re using. I had an issue with that mounting plate seal = on my 20B after about the first 50 hours. It worked part way out of it’s = socket (I guess it was against the damper plate hub) and resulted in some minor leakage. I had Tracy send me a new seal, which I didn’t like because; = IIRC, the outer part of the seal did not have the coated metal flange, just hard = elastomer material. I felt that after running hot for awhile it could loosen and = not stay in place.  Tracy gave me brand and part number and I got a replacement to = match the original.  Unfortunately, I can’t tell you brand and part#; = although may still have the box and old seal at the hangar.

 

Also don’t know what I did = to insure it stay in place. May have just coated it with hardening gasket maker, = or peened a couple of dents at the edge of the hole in the plate. In any case, it = has remained where it belongs for the last 150 hours. =  

 

Al

 

 

-----Original = Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Sunday, September 19, 2010 5:19 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = Check PSRU Oil Drain-back hose was Re: Watch that psru oil = seal

 

Ed,

 

You and Lynn may have hit on something = regarding the crankcase vent line being too small.  It may have been marginally acceptable with the side port engine, but way undersized for the = fire-breathing p-port.  First time I ran it real hard, out came the seal.  I = am using the stock vent line, but will go ahead and up-size it while I'm = fixing the psru seal.  

 

Mark

On Sun, Sep 19, 2010 at 8:10 = AM, Ed Anderson <eanderson@carolina.rr.com&g= t; wrote:

Mark, here's another thing = to check for - the oil drain back hose from the PSRU

 

The PSRU typically has its = oil drain-back to the oil pan which can be "pressurized" by = blow-by of the rotors.  This back pressure could  impede the flow = back of oil from the PSRU because by the time the oil in the PSRU is ready to = drain back it has dropped the oil pressure from its 80 psi input to = practically zero.  So it basically gravity feed back to the oil pan.   I guess the oil pan pressure could get to the = point of serioulsy impeding the oil blow - but I would think that much crank case pressure would have given other indications - such as blowing your dip = stick out {:>)

 

Now if the PSRU oil = drain-back became plugged/restricted/crimped  for some reason then the = pressure on the seal might eventually reach near the 80 psi input mark and that = would put considerably force on the seal.  So (as I know you already = planned) check out the drain back hose.

 

But, in any = case mechanically restraining the seal sounds like a smart ideal in any = case

 

Ed

Edward L. Anderson
Anderson Electronic Enterprises = LLC
305 = Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

Sent: Sunday, September 19, 2010 8:39 AM

Subject: [FlyRotary] Re: Watch = that psru oil seal

 

Lynn,

 

  Am I reading you right in = saying that it it was crankcase pressure, not oil pressure. And to relieve said = pressure, one needs a larger relief tube than the factory one on the oil fill. = (call it perhaps 3/16" without going to the hanger and = measuring)

 

Ben

--- On Sun, = 9/19/10, Lehanover@aol.com <Lehanover@aol.com> = wrote:


From: Lehanover@aol.com <Lehanover@aol.com>
Subject: [FlyRotary] Re: Watch that psru oil seal
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Date: Sunday, September 19, 2010, 7:14 AM

In a message = dated 9/19/2010 = 5:41:35 A.M. Eastern = Standard Time, msteitle@gmail.com writes:

Kelly,  =

 

My custom = adapter plate was built on a Bridgeport mill.  The hole spacing (and sizes) were obtained = from a drawing for the actual RD-2C plate.  Could it be a thou or two = oversize?  I guess that's possible, but I don't think so.  The = machinist that did the work is very meticulous.  However, before reassembly, = I'll definitely check it to be sure.  The bottom line is that there is = 90-100 psi trying to push it out of place.  So, I feel that a mechanical fastener is the only real way to guarantee that it stays put 100% of = the time.  

 

Mark

Anything not positively retained in aircraft, will eventually fall off. Garlock = style lip seals will just barely hold back oil splash with little to no = pressure. You see Garlocks  pressed into cavities that are cast or formed with retaining lips at the end. Not into smooth bores. More than a few = pounds against a lip seal over heats the seal and fails the lip allowing a = leak. Note the oil drainback paths in the rotary, so seals see no pressure = even beside a main bearing other than from crank case gasses.. =

 

I had a = weaver Brothers three section dry sump pump that had the pressure section in the blind end of a casting so no high pressurized oil was = exposed to a seal of any kind. The drive shaft extended from the scavenge pump = end, so any pressure pulses would of minimal size against the Garlock = seal pressed into a smooth bore in the end plate. Each session the seal = would be found dancing along the shaft with oil dripping off of everything. A competitor told me to retain the seal with a plate of some kind. Once = that very long weekend was over I did that with a plate and three little = screws. I replaced the single lip seal with 2 half width lip seals and the = plate and never had another problem. I also cut a tiny groove from the = suction side of the pump to the center of the shaft cavity. Oil drain-back to a = lower pressure area. 

 

Lip seals are = the most freedom loving seals of all. If pressurized they turn their lips = inside out and leak on you.

 

If you = persist, they will escape the bore and dump your oil out on the ground. They have = been that way since the first day. Thought should be expended on the release of = crank case gasses. The street engine has a tiny tube sticking out of the oil = filler neck. This is way too small for operation above about 3500 RPM. =

 

Lynn E. = Hanover

 

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