X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao08.cox.net ([68.230.241.31] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with ESMTP id 1117136 for flyrotary@lancaironline.net; Wed, 17 May 2006 09:21:27 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.31; envelope-from=ALVentures@cox.net Received: from BigAl ([72.192.132.90]) by fed1rmmtao08.cox.net (InterMail vM.6.01.06.01 201-2131-130-101-20060113) with ESMTP id <20060517132039.EVNJ27967.fed1rmmtao08.cox.net@BigAl> for ; Wed, 17 May 2006 09:20:39 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Date: Wed, 17 May 2006 06:20:47 -0700 Message-ID: <001501c679b4$b5fed9d0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0016_01C6797A.09A272D0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0016_01C6797A.09A272D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 Richard, are you saying that the metering oil nozzles that inject oil = into the combustion chamber should have a vacuum line attached to the top = opening of the injector nozzle? I recall a discussion some time ago where I = thought you said that it was OK for those connections to be open to the = atmosphere. =20 I would say that it is OK for them to be open to the atmosphere. The = reason to connect them to the manifold is to get filtered air, and to modulate = the differential pressure across the valve. At low throttle there would be = low pressure in both manifold and rotor housing. I have no idea of the full story of the pressure dynamics over the throttle range. =20 If the vacuum line is disconnected, the oil being pumped into the rotor housing drop by drop is not spread cross wise along the apex seal. Therefore, the oil will do next to nothing in regard to cooling or lubricating the apex seal.=20 =20 Based on experience of others, this appears to be an overstatement. Rotories have run thousands of hours with no air to the nozzles. There = may be some evidence of wear patterns indicating that the tip seal travels = some distance (maybe 4-5") from the point of injection before the oil spreads = to the ends of the seals, but I'm not aware of any direct comparison wear = with and without the air flow. Maybe some of our racing friends can have = some input on this. =20 Al ------=_NextPart_000_0016_01C6797A.09A272D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

Richard, are you = saying that the metering oil nozzles that inject oil into the combustion = chamber should have a vacuum line attached to the top opening of the injector = nozzle?  I recall a discussion some time ago where I thought you said that = it was OK for those connections to be open to the atmosphere.

 

I would say that it is OK for = them to be open to the atmosphere.  The reason to connect them to the manifold = is to get filtered air, and to modulate the differential pressure across the = valve. At low throttle there would be low pressure in both manifold and rotor = housing. I have no idea of the full story of the pressure dynamics over the = throttle range.

 

If the vacuum line is disconnected, the oil being = pumped into the rotor housing drop by drop is not spread cross wise along the = apex seal. Therefore, the oil will do next to nothing in regard to cooling or lubricating the apex seal.

 

Based on experience of others, = this appears to be an overstatement.  Rotories have run thousands of hours with = no air to the nozzles.  There may be some evidence of wear patterns = indicating that the tip seal travels some distance (maybe 4-5”) from the point of injection before the oil spreads to the ends of the seals, but I’m = not aware of any direct comparison wear with and without the air flow. =  Maybe some of our racing friends can have some input on = this.

 

Al

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