X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from alnrmhc16.comcast.net ([206.18.177.56] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2083034 for flyrotary@lancaironline.net; Mon, 04 Jun 2007 09:01:28 -0400 Received-SPF: none receiver=logan.com; client-ip=206.18.177.56; envelope-from=wschertz@comcast.net Received: from wschertzpc (c-24-7-194-231.hsd1.il.comcast.net[24.7.194.231]) by comcast.net (alnrmhc16) with SMTP id <20070604130049b1600o0jdre>; Mon, 4 Jun 2007 13:00:49 +0000 Message-ID: <3A75F822E648450EB3A90956483BA650@WschertzPC> From: "Bill Schertz" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: EC-2/EM-2 manifold pressure Date: Mon, 4 Jun 2007 08:00:48 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0128_01C7A67E.764FA650" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16386 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16386 This is a multi-part message in MIME format. ------=_NextPart_000_0128_01C7A67E.764FA650 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Ed Bill Schertz KIS Cruiser #4045 ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Monday, June 04, 2007 7:20 AM Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure If you set your field altimeter so the needles point to field = elevation then the manifold pressure of your (engine not running) should = ideally read the same. But throw in transducers and calibration and = instrument error and well - you know =3D differences!! Ed ----- Original Message -----=20 From: Bill Schertz=20 To: Rotary motors in aircraft=20 Sent: Monday, June 04, 2007 8:02 AM Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure Al, thanks for the clarification on what sensor the EM2 is reading. When I set an 'old fashioned' altimeter to field elevation, the = engine is not running, isn't the Kolsman window reading the local = pressure -- ie the 'manifold' pressure? Bill Schertz KIS Cruiser #4045 ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Sunday, June 03, 2007 11:55 AM Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure Ed, When I have my EM-2 on, EC-2 off, the Manifold pressure reads the = barometric pressure (29.7 today). When I then turn on the EC-2, the manifold pressure increases to = 32.9. This seems peculiar, have you noticed anything like this? Bill Schertz KIS Cruiser #4045 When the EC2 is off, it is using the reading from the sensor in = the EM2. When it is on, it is reading the sensor in the EC2. I have = also found considerable disagreement on these sensors. I also found = that I had to change the calibration on the MAP pressure channel on the = EM2 to get the correct reading (with EC2 on, we don't care what the = sensor in the EM2 is reading). I have no idea why the calibration = should be different on different units that use the same sensor; but = there it is. You can get a vacuum gage (actually a pressure gage, so = you have to subtract from atmospheric) at a reasonable price from = McMaster-Carr, or I could loan you mine. =20 Also, it should not necessarily read the barometric pressure; you = have to adjust for altitude. Barometric is equivalent sea level (or = something like that). Al ------=_NextPart_000_0128_01C7A67E.764FA650 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks Ed
Bill Schertz
KIS Cruiser #4045
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Monday, June 04, 2007 = 7:20 AM
Subject: [FlyRotary] Re: = EC-2/EM-2=20 manifold pressure

If you set your field altimeter so the needles = point to=20 field elevation then the manifold pressure of your (engine not = running) should=20 ideally read the same.  But throw in transducers and calibration = and=20 instrument error and well - you know =3D differences!!
 
Ed
----- Original Message -----
From:=20 Bill=20 Schertz
To: Rotary motors in = aircraft=20
Sent: Monday, June 04, 2007 = 8:02=20 AM
Subject: [FlyRotary] Re: = EC-2/EM-2=20 manifold pressure

Al, thanks for the clarification on = what sensor=20 the EM2 is reading.
 
When I set an 'old fashioned' = altimeter to=20 field elevation, the engine is not running, isn't the Kolsman window = reading=20 the local pressure -- ie the 'manifold' pressure?
Bill Schertz
KIS Cruiser = #4045
----- Original Message ----- =
From:=20 Al=20 Gietzen
To: Rotary motors in = aircraft=20
Sent: Sunday, June 03, 2007 = 11:55=20 AM
Subject: [FlyRotary] Re: = EC-2/EM-2=20 manifold pressure

 

Ed,

When = I have my=20 EM-2 on, EC-2 off, the Manifold pressure reads the barometric = pressure=20 (29.7 today).

 

When = I then turn=20 on the EC-2, the manifold pressure increases to 32.9.  This = seems=20 peculiar, have you noticed anything like = this?

 

Bill=20 Schertz
KIS Cruiser #4045

When = the EC2 is=20 off, it is using the reading from the sensor in the EM2. =  When it is=20 on, it is reading the sensor in the EC2. I have also found = considerable=20 disagreement on these sensors.  I also found that I had to = change the=20 calibration on the MAP pressure channel on the EM2 to get the = correct=20 reading (with EC2 on, we don=92t care what the sensor in the EM2 = is=20 reading).  I have no idea why the calibration should be = different on=20 different units that use the same = sensor; but=20 there it is.  You can get a vacuum gage (actually a pressure = gage, so=20 you have to subtract from atmospheric) at a reasonable price from=20 McMaster-Carr, or I could loan you mine. 

 

Also, = it should=20 not necessarily read the barometric pressure; you have to adjust = for=20 altitude.  Barometric is equivalent sea level (or something = like=20 that).

 

Al

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