X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao101.cox.net ([68.230.241.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.9) with ESMTP id 3231832 for flyrotary@lancaironline.net; Tue, 21 Oct 2008 00:41:28 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.45; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao101.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20081021044051.DKSX6175.fed1rmmtao101.cox.net@fed1rmimpo02.cox.net> for ; Tue, 21 Oct 2008 00:40:51 -0400 Received: from BigAl ([72.192.137.74]) by fed1rmimpo02.cox.net with bizsmtp id VGgq1a00L1cVYgg04GgqXK; Tue, 21 Oct 2008 00:40:50 -0400 X-Authority-Analysis: v=1.0 c=1 a=aqmzCw2Kk-oA:10 a=OOMK1h3CBdYA:10 a=x8PezN58QPq_jVjkIj8A:9 a=5fdmpKhjFgtfiZymQvYA:7 a=0BSu6rhAso_TnROU5HZX4PcTySsA:4 a=zUBsD6tbDSsA:10 a=JlAVf6_HogrmX0HsTO0A:9 a=84m5aCXB8XR20BQ-QGgA:7 a=c4zjI0DtFG9ZmG8UvkEyEPQJ12UA:4 a=37WNUvjkh6kA:10 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Water in Fuel?? (or another adventure in the aviation events of Ed Anderson) Date: Mon, 20 Oct 2008 21:42:30 -0800 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C932FC.C1030DC0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0007_01C932FC.C1030DC0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable John, I think your analysis makes lots of sense for a gravity fed fuel system (i.e. no pumps). However, I would think that the EFI pumps would churn the water and fuel together pretty thoroughly.=20 Yes the pump will mix it up pretty well; but it will separate out again = in the line..=20 =20 In any case, I did use some auto gas back a couple of flights ago and = did not like it. The engine had a bit of a miss - nothing bad, but just noticeable - could have been the plugs needing a change to be fair It seems to me this is unlikely an effect of using mogas. Running my = engine on the dyno showed a very slight improvement in performance with 87 = octane mogas over 100LL. I think the theory was faster propagation of the = flame front in the odd-shaped combustion chamber. And as you know, the lead = is no friend to the spark plugs. =20 Al =20 ------=_NextPart_000_0007_01C932FC.C1030DC0 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

John, I think = your analysis makes lots of sense for a gravity fed fuel system (i.e. no pumps).  However, I would think that the EFI pumps would churn the = water and fuel together pretty thoroughly. 

Yes the pump will mix it up = pretty well; but it will separate out again in the line..

 

In any case, I = did use some auto gas back a couple of flights ago and did not like it.  = The engine had a bit of a miss – nothing bad, but just noticeable = – could have been the plugs needing a change to be fair

It seems to me this is unlikely = an effect of using mogas.  Running my engine on the dyno showed a very = slight improvement in performance with 87 octane mogas over 100LL.  I = think the theory was faster propagation of the flame front in the odd-shaped = combustion chamber.  And as you know, the lead is no friend to the spark = plugs.

 

Al

 

------=_NextPart_000_0007_01C932FC.C1030DC0--