X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from zproxy.gmail.com ([64.233.162.195] verified) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 711871 for flyrotary@lancaironline.net; Mon, 05 Sep 2005 14:40:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.233.162.195; envelope-from=wdleonard@gmail.com Received: by zproxy.gmail.com with SMTP id z3so946089nzf for ; Mon, 05 Sep 2005 11:39:41 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=nrEbUbT91J1GNmFDvfaZJ6MVG/X+rx9wNkJnYG7MJXVBC1LeBtL6B1G3Hj7J94yFoAbLWvGBdfzVjkpwDggj84mjEs4TWJFnjeOXDEqOqDbIY1SWOIZdJLy+Nay4Pqs0CaQX5kl7+nvfu5ZvQR2SgUFNQCmwsl0MzCBUUvQRENI= Received: by 10.36.79.10 with SMTP id c10mr2496428nzb; Mon, 05 Sep 2005 11:39:41 -0700 (PDT) Received: by 10.36.8.13 with HTTP; Mon, 5 Sep 2005 11:39:41 -0700 (PDT) Message-ID: <1c23473f050905113930ab8f19@mail.gmail.com> Date: Mon, 5 Sep 2005 11:39:41 -0700 From: David Leonard To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Another great flying day = another day of troubleshooting In-Reply-To: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_23592_14011051.1125945581366" References: ------=_Part_23592_14011051.1125945581366 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Ed I am talking MAP in both cases. I don't see how 26" MAP is higher than= =20 36"MAP. But I learned the old math :-) Dave On 9/5/05, Ed Anderson wrote:=20 >=20 > Well, actually it is absolute pressure that the spark plug is reacting to= .=20 > In this example, the absolute pressure in the intake is 1.234" HG higher= =20 > at 10,000 with your 26 " boost than at sea level with your 36" of boost..= =20 > This would contribute to an increased pressure in the combustion chamber= =20 > when it is compressed over the sea level compression pressure. Therefore,= =20 > the spark plug is facing a tougher task at 10,000 than at Sea level (in t= his=20 > example). > Ed >=20 > ----- 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=20 > troubleshooting >=20 > Actually, Dave you had a higher pressure ratio (manifold to ambient) a= t=20 > > 10,000 feet with 26" boost than at sea level with 36". At sea level the= =20 > > pressure ratio would be 36/29.92 =3D 1.20. At 10,000 ft ambient pressur= e =3D=20 > > 20.57 " hg , so the pressure ratio would be 26/20.57 =3D 1.26. Not much= =20 > > greater, but it was higher by approx.1.23" Hg. (1.20 -1.26 =3D .06 *20.= 57=3D=20 > > 1.234" Hg).=20 > >=20 > > Ed A > >=20 > > Right. But what does the plug know about the ambient pressure? I though= t=20 > that it was just the absolute density of the charge that was contributing= to=20 > SAG.=20 >=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=20 >=20 >=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 ------=_Part_23592_14011051.1125945581366 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
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

 
On 9/5/05, E= d Anderson <eanderson@c= arolina.rr.com> wrote:
Well, actually it is absolute pressure that the s= park plug is reacting to.  In this example, the absolute pressure in t= he 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 faci= ng a tougher task at 10,000 than at Sea level (in this example).
 
Ed
----- Original Message -----
Sent: Monday, September 05, 2005 12:= 57 PM
Subject: [FlyRotary] Re: Another gre= at flying day =3D another day of troubleshooting

 

 Actually, Dave you had a higher pressure ratio (manifold to ambien= t) 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 10,0= 00 ft ambient pressure =3D=20 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).

Ed A

Righ= t.  But what does the plug know about the ambient pressure?  I th= ought that it was just the absolute density of the charge that was contribu= ting to SAG.=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
=



--
Dave Leonard
Turbo Rotary RV-6 N4= VY
http= ://members.aol.com/_ht_a/rotaryroster/index.html
http://members.aol.com/_ht_a/vp4skydoc/index.html=20 ------=_Part_23592_14011051.1125945581366--