X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-iw0-f180.google.com ([209.85.214.180] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4472552 for flyrotary@lancaironline.net; Sun, 19 Sep 2010 11:34:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.214.180; envelope-from=msteitle@gmail.com Received: by iwn8 with SMTP id 8so4609137iwn.25 for ; Sun, 19 Sep 2010 08:34:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=dtiYK7WYdz0eeygk6yv3EhyAEz4Wx1zBoK96RikffZU=; b=IOIneu6Mux7dLm1x4J92blzJaqF3sKrOVc2rue3MxPCS3NHLtB1m/y18o7ZRda+J3K 5+5G2dEP/o8oIMxmjLgCVlE12vSiHWaRJ/8BW6pHEWzl0hym84C10o9r/NjxWpOcQBJY wXDVr5uce0kpCU2n+aUtwkv7ftFvkt8NR/T5w= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Kurvg8drB1uX53fdpDkgWSny2cZnBkoWaU8PaBijOaSx8vW0NZxsIZpG4eECcm2QHO c9MQiF4izVEwubOu6luC4cYkBmYLHrv1SWGTI8J36jiUUVA7bNqwX20pL21b7et3od8Q y5d4v6lSYkG6jz9BZEmMbEhvXVm6sa7TFSjm0= MIME-Version: 1.0 Received: by 10.231.34.139 with SMTP id l11mr8615198ibd.141.1284910454847; Sun, 19 Sep 2010 08:34:14 -0700 (PDT) Received: by 10.231.173.137 with HTTP; Sun, 19 Sep 2010 08:34:14 -0700 (PDT) In-Reply-To: References: Date: Sun, 19 Sep 2010 10:34:14 -0500 Message-ID: Subject: Re: [FlyRotary] psru oil seal From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=002215048ac73ac16f04909e8726 --002215048ac73ac16f04909e8726 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Al, The seal was leaking slightly a while back and I replaced the stock seal with a Timkin. It hadn't been a problem for the last 100+ hours. I'll fee= l much better knowing it is retained mechanically. I don't think the drain (-6 AN) is plugged, but I'll check it while it is apart. Mark On Sun, Sep 19, 2010 at 10:40 AM, Al Gietzen wrote: > Mark; > > > > I=92m 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 =91splash= =92 > around the shaft. Given the large quantity of oil you lost in a short tim= e > would suggest significant pressure and a backup of oil. Do you have at le= ast > a 3/8=94 line for the drain-back, and could there be some restriction? > > > > You also might want check what kind/brand of seal you=92re using. I had a= n > issue with that mounting plate seal on my 20B after about the first 50 > hours. It worked part way out of it=92s socket (I guess it was against th= e > damper plate hub) and resulted in some minor leakage. I had Tracy send me > a new seal, which I didn=92t like because; IIRC, the outer part of the se= al > did not have the coated metal flange, just hard elastomer material. I fel= t > 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=92t tell you brand and part#; although ma= y > still have the box and old seal at the hangar. > > > > Also don=92t know what I did to insure it stay in place. May have just co= ated > it with hardening gasket maker, or peened a couple of dents at the edge o= f > 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] *O= n > 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 po= rt > engine, but way undersized for the fire-breathing p-port. First time I r= an > it real hard, out came the seal. I am using the stock vent line, but wil= l > 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 > wrote: > > Mark, here's another thing to check for - the oil drain back hose from th= e > 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 PSR= U > is ready to drain back it has dropped the oil pressure from its 80 psi in= put > 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 t= he > oil blow - but I would think that much crank case pressure would have giv= en > other indications - such as blowing your dip stick out {:>) > > > > Now if the PSRU oil drain-back became plugged/restricted/crimped for som= e > reason then the pressure on the seal might eventually reach near the 80 p= si > input mark and that would put considerably force on the seal. So (as I k= now > 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 > > *From:* Ben Schneider > > *Sent:* Sunday, September 19, 2010 8:39 AM > > *To:* Rotary motors in aircraft > > *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 tub= e > than the factory one on the oil fill. (call it perhaps 3/16" without goin= g > to the hanger and measuring) > > > > 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, > > > > 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. Cou= ld > 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 1= 00% > 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 for= med > 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 pressur= e > 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 expo= sed > to a seal of any kind. The drive shaft extended from the scavenge pump en= d, > 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 tha= t > very long weekend was over I did that with a plate and three little screw= s. > 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 tin= y > tube sticking out of the oil filler neck. This is way too small for > operation above about 3500 RPM. > > > > Lynn E. Hanover > > > --002215048ac73ac16f04909e8726 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Al,

The seal was leaking slightly a while back and I rep= laced the stock seal with a Timkin. =A0It hadn't been a problem for the= last 100+ hours. =A0I'll feel much better knowing it is retained mecha= nically. =A0I don't think the drain (-6 AN) is plugged, but I'll ch= eck it while it is apart.

Mark

On Sun, Sep 19, = 2010 at 10:40 AM, Al Gietzen <ALVentures@cox.net> wrote:

Mark;

=A0

I=92m very ple= ased to hear it happened while still at the airport.

=A0

There should b= e little or no pressure forcing it out; and there should be no significant level of oil in the hous= ing, so it is just the =91splash=92 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=94 line for the drain-back, and could there be some restriction?=A0

=A0

You also might= want check what kind/brand of seal you=92re 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=92s 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=92t like because; IIRC, the outer part of the seal did not have the coated metal flange, just hard elas= tomer material. I felt that after running hot for awhile it could loosen and not = stay in place. =A0Tracy gave me brand and part numb= er and I got a replacement to match the original.=A0 Unfortunately, I can=92t tell you brand and part#; although may still have the box and old seal at the hangar.

=A0

Also don=92t k= now what I did to insure it stay in place. May have just coated it with hardening gasket maker, or p= eened 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. =A0

=A0

Al

=A0

=A0

-----Original M= essage-----
From: Rotary motors in aircr= aft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Sunday, September 19, 2010 5:19 AM=
To: Rotary motors in aircraf= t
Subject: [FlyRotary] Re: Che= ck PSRU Oil Drain-back hose was Re: Watch that psru oil seal

=A0

Ed,

=A0

You and Lynn may have hit= on something regarding the crankcase vent line being too small. =A0It may have been marginally acceptable with the side port engine, but way undersized for the fire-breat= hing p-port. =A0First time I ran it real hard, out came the seal. =A0I am using the stock vent line, but will go ahead and up-size it while I'm f= ixing the psru seal. =A0

=A0

Mark

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

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

=A0

The PSRU typicall= y has its oil drain-back to the oil pan which can be "pressurized" by blow-by o= f the rotors.=A0 This back pressure=A0could =A0impede 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.=A0=A0So it basically gravity feed back to the oil pan.=A0=A0=A0I 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 stic= k out {:>)

=A0

Now if the PSRU o= il drain-back became plugged/restricted/crimped =A0for some reason then the pressure on the seal might eventually reach near=A0the 80 psi input mark and that would put considerably force on the seal.=A0 So (as I know you already planned) check out the drain back hose.

=A0

But, in any case= =A0mechanically restraining the seal sounds like a smart ideal in any case

=A0

Ed<= /p>

Edward L. Anderson
Anders= on Ele= ctronic Enterprises LLC
305 Re= efton Road
Weddin= gton, = 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

=A0

Lynn,

=A0

=A0=A0Am 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. (cal= l it perhaps 3/16" without going to the hanger and measuring)

=A0

Ben

--- On Sun, = 9/19/10, Leh= anover@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 d= ated 9/19/2010 5:41:35 A.M. Eastern Standard Time, msteitle@gm= ail.com writes:

Kelly,=A0

=A0

My custom adap= ter plate was built on a B= ridgeport mill. =A0The ho= le spacing (and sizes) were obtained from a drawing for the actual RD-2C plate. =A0Could it be a thou or two oversize= ? =A0I guess that's possible, but I don't think so. =A0The machinis= t that did the work is very meticulous. =A0However, before reassembly, I'll definitely check it to be sure. =A0The bottom line is that there is 90-10= 0 psi trying to push it out of place. =A0So, I feel that a mechanical fastener is the only real way to guarantee that it stays put 100% of the time. =A0

=A0

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. Y= ou see Garlocks=A0 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.. <= /p>

=A0

I had a weaver Brothers three section dry sump pump that had the pressure section in=A0the 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=A0against 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 tha= t very long weekend was over I did that with a plate and three little screw= s. I replaced the single lip seal=A0with 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.=A0

=A0

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

=A0

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 cra= nk case gasses. The street engine has a tiny tube sticking out of the oil fi= ller neck. This is way too small for operation above about 3500 RPM.

=A0

Lynn E. Hanove= r

=A0


--002215048ac73ac16f04909e8726--