X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 711904 for flyrotary@lancaironline.net; Mon, 05 Sep 2005 16:13:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-065-188-083-049.carolina.res.rr.com [65.188.83.49]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j85KD4Y5028273 for ; Mon, 5 Sep 2005 16:13:05 -0400 (EDT) Message-ID: <000701c5b255$f7acabe0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Another great flying day = another day of troubleshooting Date: Mon, 5 Sep 2005 16:11:14 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01C5B234.705AA780" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0004_01C5B234.705AA780 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable You're absolutely correct. The pressure ratio has nothing to do with = MAP. I knew I should have had a second cup of coffee this morning. = Back to trying to get a graphical LCD to work - hopefully with more = success than encountered on this topic {:>) Duh! Ed ----- Original Message -----=20 From: David Leonard=20 To: Rotary motors in aircraft=20 Sent: Monday, September 05, 2005 2:39 PM Subject: [FlyRotary] Re: Another great flying day =3D another day of = troubleshooting Ed I am talking MAP in both cases. I don't see how 26" MAP is higher = than 36"MAP. But I learned the old math :-) Dave =20 On 9/5/05, Ed Anderson wrote:=20 Well, actually it is absolute pressure that the spark plug is = reacting to. In this example, the absolute pressure in the intake is = 1.234" HG higher at 10,000 with your 26 " boost than at sea level with = your 36" of boost.. This would contribute to an increased pressure in = the combustion chamber when it is compressed over the sea level = compression pressure. Therefore, the spark plug is facing a tougher = task at 10,000 than at Sea level (in this example).=20 Ed ----- Original Message -----=20 From: David Leonard=20 To: Rotary motors in aircraft=20 Sent: Monday, September 05, 2005 12:57 PM Subject: [FlyRotary] Re: Another great flying day =3D another day = of troubleshooting =20 Actually, Dave you had a higher pressure ratio (manifold to = ambient) at 10,000 feet with 26" boost than at sea level with 36". At = sea level the pressure ratio would be 36/29.92 =3D 1.20. At 10,000 ft = ambient pressure =3D 20.57 " hg , so the pressure ratio would be = 26/20.57 =3D 1.26. Not much greater, but it was higher by approx.1.23" = Hg. (1.20 -1.26 =3D .06 *20.57 =3D 1.234" Hg).=20 Ed A Right. But what does the plug know about the ambient pressure? I = thought that it was just the absolute density of the charge that was = contributing to SAG.=20 --=20 Dave Leonard Turbo Rotary RV-6 N4VY http://members.aol.com/_ht_a/rotaryroster/index.html=20 http://members.aol.com/_ht_a/vp4skydoc/index.html=20 --=20 Dave Leonard Turbo Rotary RV-6 N4VY http://members.aol.com/_ht_a/rotaryroster/index.html http://members.aol.com/_ht_a/vp4skydoc/index.html ------=_NextPart_000_0004_01C5B234.705AA780 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

You're absolutely correct. The pressure = ratio has=20 nothing to do with MAP. I knew I should have had a second = cup of=20 coffee this morning. Back to trying to get a graphical LCD = to work -=20 hopefully with more success than encountered on this topic {:>)=20 Duh!

Ed

----- Original Message -----

From:=20 David=20 Leonard

To: Rotary motors in = aircraft

Sent: Monday, September 05, = 2005 2:39=20 PM

Subject: [FlyRotary] Re: = Another great=20 flying day =3D another day of troubleshooting

Ed I am talking MAP in both cases. I don't see how 26" MAP = is=20 higher than 36"MAP. But I learned the old math :-)

Dave

On 9/5/05, Ed=20 Anderson <eanderson@carolina.rr.com&g= t;=20 wrote:=20

Well, actually it is absolute pressure that = the spark=20 plug is reacting to. In this example, the absolute pressure in = the=20 intake is 1.234" HG higher at 10,000 with your 26 " boost than at = sea level=20 with your 36" of boost.. This would contribute to an increased = pressure in the combustion chamber when it is compressed over the = sea level=20 compression pressure. Therefore, the spark plug is facing a = tougher=20 task at 10,000 than at Sea level (in this example). =

Ed

----- Original Message ----- =

From: = David = Leonard

To: Rotary = motors in=20 aircraft

Sent: Monday, September 05, = 2005=20 12:57 PM

Subject: [FlyRotary] Re: = Another=20 great flying day =3D another day of troubleshooting

Actually, Dave you had a higher pressure ratio = (manifold to=20 ambient) at 10,000 feet with 26" boost than at sea level with=20 36". At sea level the pressure ratio would be 36/29.92 = =3D=20 1.20. At 10,000 ft ambient pressure =3D 20.57 " hg , so = the=20 pressure ratio would be 26/20.57 =3D = 1.26. =20 Not much greater, but it was higher by approx.1.23" Hg. (1.20 = -1.26 =3D=20 .06 *20.57 =3D 1.234" Hg).

Ed=20 A
Right. But what = does the=20 plug know about the ambient pressure? I thought that it was = just the=20 absolute density of the charge that was contributing to SAG. =

--=20
Dave Leonard
Turbo Rotary RV-6 N4VY
http://members.aol.com/_ht_a/rotaryroster/index.html=20
http://members.aol.com/_ht_a/vp4skydoc/index.html=20

--
Dave=20 Leonard
Turbo Rotary RV-6 N4VY
http://memb= ers.aol.com/_ht_a/rotaryroster/index.html
http://members= .aol.com/_ht_a/vp4skydoc/index.html=20 ------=_NextPart_000_0004_01C5B234.705AA780--