Return-Path: Received: from mtiwmhc11.worldnet.att.net ([204.127.131.115] verified) by logan.com (CommuniGate Pro SMTP 4.2) with ESMTP id 351936 for flyrotary@lancaironline.net; Wed, 04 Aug 2004 11:45:10 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.131.115; envelope-from=keltro@att.net Received: from 204.127.135.40 ([204.127.135.40]) by worldnet.att.net (mtiwmhc11) with SMTP id <200408041544401110044tvve>; Wed, 4 Aug 2004 15:44:40 +0000 Received: from [209.247.222.100] by 204.127.135.40; Wed, 04 Aug 2004 15:44:40 +0000 From: keltro@att.net (Kelly Troyer) To: "Rotary motors in aircraft" Subject: Re: May not work above 8000 MSL ] Date: Wed, 04 Aug 2004 15:44:40 +0000 Message-Id: <080420041544.14243.41110467000D0F36000037A32160280748019D9B040A05@att.net> X-Mailer: AT&T Message Center Version 1 (Jul 19 2004) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_14243_1091634280_0" --NextPart_Webmail_9m3u9jl4l_14243_1091634280_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Snip > > > From: "Ed Anderson" > > > Date: 2004/08/04 Wed AM 07:16:02 EDT > > > To: "Rotary motors in aircraft" > > > Subject: [FlyRotary] Re: May not work above 8000 MSL was [FlyRotary] > > > Re: Oil injection, and more > > > > > > You may be correct, Al. Without testing it would be hard to say. > > > > > > No question my theory could be wrong - but as you say something must have > made Atkins come to the conclusion that the metering pump does not work above > 8000. If his claim is valid - then there must be some cause related to > altitude. The only part of the fuel metering system that would be affected by > altitude that I can see is the oil feed from the shaft boss to the pump. > > > > > > We know that as pressure changes across an aperture will cause the flow > rate to change - whether (as you point out) the difference due to altitude is > significant enough to account for any lessening of oil flow is the question. > Whether or not a few pi would ensure adequately flow sufficient CCs of oil will > depend on the size of the orifice through which the oil flows. I agree if the > aperture is sufficiently large then a few PSI change in pressure will make > little (if any) difference in flow. However, if the orifice is small and the > flow barely adequate to meet the needs say at 14.7 psi then 11 psi could lessen > the flow. Not claiming that flow would cease, but it may well be diminished. > > > > > > My 0.02 > > > > > > Ed Snip > What about the vacuum of the rotors drawing the oil into the chambers? That > happens at any altitude. > Marc Wiese > Very good observation Marc! Isn't the rotor tip seal past the oil injection jet in the rotor housing before compression of the intake charge begins? IMHO Kelly Troyer --NextPart_Webmail_9m3u9jl4l_14243_1091634280_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

 
Snip
> > > From: "Ed Anderson"
> > > Date: 2004/08/04 Wed AM 07:16:02 EDT
> > > To: "Rotary motors in aircraft"
> > > Subject: [FlyRotary] Re: May not work above 8000 MSL was [FlyRotary]
> > > Re: Oil injection, and more
> > >
> > > You may be correct, Al. Without testing it would be hard to say.
> > >
> > > No question my theory could be wrong - but as you say something must have
> made Atkins come to the conclusion that the metering pump does not work above
> 8000. If his claim is valid - then there must be some cause related to
> altitude. The only part of the fuel metering system that would be affected by
> altitude that I can see is the oil feed from the shaft boss to the pump.
> > >
> > > We know that as pressure changes across an aperture will cause the flow
> rate to change - whether (as you point out) the difference due to altitude is
> significant enough to account for any lessening of oil flow is the question.
> Whether or not a few pi would ensure adequately flow sufficient CCs of oil will
> depend on the size of the orifice through which the oil flows. I agree if the
> aperture is sufficiently large then a few PSI change in pressure will make
> little (if any) difference in flow. However, if the orifice is small and the
> flow barely adequate to meet the needs say at 14.7 psi then 11 psi could lessen
> the flow. Not claiming that flow would cease, but it may well be diminished.
> > >
> > > My 0.02
> > >
> > > Ed 

Snip
 
> What about the vacuum of the rotors drawing the oil into the chambers? That
> happens at any altitude.
> Marc Wiese
> 


  Very good observation Marc! Isn't the rotor tip seal  past the oil injection jet

in the rotor housing before compression of the intake charge begins? IMHO

 

Kelly Troyer

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