Return-Path: <13brv3@bellsouth.net> Received: from imf17aec.mail.bellsouth.net ([205.152.59.65] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2576125 for flyrotary@lancaironline.net; Thu, 11 Sep 2003 12:40:39 -0400 Received: from rad ([68.212.14.21]) by imf17aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030911164039.XZNV17943.imf17aec.mail.bellsouth.net@rad> for ; Thu, 11 Sep 2003 12:40:39 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: Intake temps Date: Thu, 11 Sep 2003 11:40:39 -0500 Message-ID: <00ae01c37883$6eedc130$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00AF_01C37859.8617B930" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_00AF_01C37859.8617B930 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Idle at 2000 rpm can generate around 15" of manifold vacuum and that converts to 45 deg F temperature drop. That is waaaaaaay more than the = dew point spread in most places. A lot of the heat (and therefore temp = drop) gets absorbed by the warm environment, but not all. It is the same phenomenon that causes carb ice. Just a theory .... Jim S. =20 I've seen the same condensation on my intake when running at low power = on the ground. Now that you mention it, I realize that my air temp sensor = is not in the best location. I have it in the pressurized air box on the outside of the throttle body. As I understand it, the pressure drop, = and temp change will be on the engine side of the throttle body. Since this = can change the temp quite a bit, I bet that's why I have such a difference between the A and B controller (B doesn't use the air temp sensor) at = low power on the ground. =20 =20 Where are you guys putting your air temp sensors? =20 Cheers, Rusty (new oil cooler arriving today) =20 ------=_NextPart_000_00AF_01C37859.8617B930 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message

Idle at 2000 rpm can generate around 15" of manifold = vacuum and=20 that converts to 45 deg F temperature drop.  That is waaaaaaay more = than=20 the dew point spread in most places.  A lot of the heat (and = therefore temp=20 drop) gets absorbed by the warm environment, but not all.  It is = the same=20 phenomenon that causes carb ice. Just a theory .... Jim S.

 
I've = seen the same=20 condensation on my intake when running at low power on the ground.  = Now=20 that you mention it, I realize that my air temp sensor is not in the = best=20 location.  I have it in the pressurized air box on the outside of = the=20 throttle body.  As I understand it, the pressure drop, and temp = change will=20 be on the engine side of the throttle body.  Since this can change = the temp=20 quite a bit, I bet that's why I have such a difference between the A and = B=20 controller (B doesn't use the air temp sensor) at low power on the = ground. =20
 
Where = are you guys=20 putting your air temp sensors?
 
Cheers,
Rusty = (new oil cooler=20 arriving today)
 




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