X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from sccrmhc13.comcast.net ([63.240.76.28] verified) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 720559 for flyrotary@lancaironline.net; Tue, 13 Sep 2005 12:26:49 -0400 Received-SPF: none receiver=logan.com; client-ip=63.240.76.28; envelope-from=kenpowell@comcast.net Received: from 204.127.205.142 (sccrwbc57.asp.att.net[204.127.205.157]) by comcast.net (sccrmhc13) with SMTP id <2005091316260401300d4900e>; Tue, 13 Sep 2005 16:26:04 +0000 Received: from [166.102.160.132] by 204.127.205.142; Tue, 13 Sep 2005 16:26:03 +0000 From: kenpowell@comcast.net To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: New Subject... Vapor pressure changes with premix oil Date: Tue, 13 Sep 2005 16:26:03 +0000 Message-Id: <091320051626.11586.4326FD9B0006E90200002D42220588601404040A99019F020A05@comcast.net> X-Mailer: AT&T Message Center Version 1 (Dec 17 2004) X-Authenticated-Sender: a2VucG93ZWxsQGNvbWNhc3QubmV0 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_11586_1126628763_0" --NextPart_Webmail_9m3u9jl4l_11586_1126628763_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Bobby, be VERY careful with your thought process here. I suspect that you are looking for some insurance from VAPOR LOCK. I seriously doubt that the oil will add enough margin to be measurable. The only way to insure safety is with a correct fuel system design. I am going to use a design similar to Tracy's but I'm going to put 2 fuel pumps in the tank (same tank) instead of downstream of the tanks. Ken Powell Bryant, Arkansas 501-847-4721 C150 / RV-4 under construction -------------- Original message -------------- > Bill, Jim, > > I suspect that mixing the oil in the fuel tanks may give us more > altitude margin than then Lyc and Subi's running auto fuel. We need a > good chemist to take a SWAG at this. I could not find any research > published on the web. > > Bobby > > -----Original Message----- > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On > Behalf Of Jim Sower > Sent: Tuesday, September 13, 2005 12:23 AM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: New Subject... Vapor pressure changes with > premix oil > > Lower vapor pressure is better. Mogas has high vapor pressure. Oil > premixed would tend to lower the vapor pressure (as well as octane, as > you stated), but not enough to measure/detect IMO. > > WRJJRS@aol.com wrote: > > > In a message dated 9/12/2005 4:18:48 PM Pacific Standard Time, > > bhughes@qnsi.net writes: > > > > Anyone have any data as to what affect mixing two stroke oil with > > auto fuel does to vapor pressure? Will it make auto fuel more > > tolerant at higher altitudes or less? > > > > Bobby > > > > Since the oil is harder to vaporize it should reduce the tendance to > > vapor lock. I always get crossed up on vapor pressure, higher is > > harder to vaporize? I sure you get the idea. > > Bill Jepson > > PS the oil can reduce the octane level if mixed in high enough > > quantity although at the 100:1 needed for the rotary I doubt if you > > would even notice it's there. Bill > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ --NextPart_Webmail_9m3u9jl4l_11586_1126628763_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

Bobby, be VERY careful with your thought process here. I suspect that you are looking for some insurance from VAPOR LOCK. I seriously doubt that the oil will add enough margin to be measurable. The only way to insure safety is with a correct fuel system design. I am going to use a design similar to Tracy's but I'm going to put 2 fuel pumps in the tank (same tank) instead of downstream of the tanks.

Ken Powell
Bryant, Arkansas
501-847-4721
C150 / RV-4 under construction

-------------- Original message --------------

> Bill, Jim,
>
> I suspect that mixing the oil in the fuel tanks may give us more
> altitude margin than then Lyc and Subi's running auto fuel. We need a
> good chemist to take a SWAG at this. I could not find any research
> published on the web.
>
> Bobby
>
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
> Behalf Of Jim Sower
> Sent: Tuesday, September 13, 2005 12:23 AM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: New Subject... Vapor pressure changes with
> premix oil
>
> Lower vapor pressure is better. Mogas has high vapor pressure. Oil
> premixed would tend to lower the vapor pressure (as well as octane, as
> you stated), but not enough to measure/detect IMO.
>
> WRJJRS@aol.com wrote:
>
> > In a message dated 9/12/2005 4:18:48 PM Pacific Standard Time,
> > bhughes@qnsi.net writes:
> >
> > Anyone have any data as to what affect mixing two stroke oil with
> > auto fuel does to vapor pressure? Will it make auto fuel more
> > tolerant at higher altitudes or less?
> >
> > Bobby
> >
> > Since the oil is harder to vaporize it should reduce the tendance to
> > vapor lock. I always get crossed up on vapor pressure, higher is
> > harder to vaporize? I sure you get the idea.
> > Bill Jepson
> > PS the oil can reduce the octane level if mixed in high enough
> > quantity although at the 100:1 needed for the rotary I doubt if you
> > would even notice it's there. Bill
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/

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