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Subject: Re: [FlyRotary] Re: EC-2/EM-2 manifold pressure
Date: Mon, 04 Jun 2007 19:04:03 -0400
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Absolutely Correct Bill. If the sensor is calibrated properly.
Bill Jepson


-----Original Message-----
From: Bill Schertz <wschertz@comcast.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, 4 Jun 2007 3:54 pm
Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure


I understand that, but what I was asking:

=A0

My field elevation is 700 feet. I set the altimeter needle to 700 feet,=20
the Kohlsman window reads (whatever it is that day), and that is the=20
manifold pressure that the EC-2 should be reading - isn't it?

Bill Schertz
KIS Cruiser #4045


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

From: Thomas Jakits

To: Rotary motors in aircraft

Sent: Monday, June 04, 2007 10:22 AM

Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure


Well Bill,

if the Kolsman window is where you set your altimeter setting (mb or=20
inches mercury) you will never see field elevation (pressure) unless=20
you are at sealevel.

=A0

E.g. if you have 29.92" at sealevel (and in the window) you still have=20
29.92 in the window (you set it there!) when=A0 you get to 6500'. Your=20
actual ambient pressure is around 23.42".... (which you should be=20
reading on your manifold pressure gauge - engine stopped...

=A0

Unless, I got it wrong the last 15 years and 9500 hours - ohhh my...!!

=A0

TJ

=A0

On 6/4/07, Bill Schertz <wschertz@comcast.net> wrote:


Al, thanks for the clarification on what sensor the EM2 is reading.

=A0

When I set an 'old fashioned' altimeter to field elevation, the engine=20
is not running, isn't the Kolsman window reading the local pressure --=20
ie the 'manifold' pressure?

Bill Schertz
KIS Cruiser #4045


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

From: Al Gietzen

To: Rotary motors in aircraft

Sent: Sunday, June 03, 2007 11:55 AM

Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure


=A0


=A0


Ed,


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


=A0


When I then turn on the EC-2, the manifold pressure increases to 32.9.=A0=20
This seems peculiar, have you noticed anything like this?


=A0


Bill Schertz
KIS Cruiser #4045

When the EC2 is off, it is using the reading from the sensor in the=20
EM2. =A0When it is on, it is reading the sensor in the EC2. I have also=20
found considerable disagreement on these sensors.=A0 I also found that I=20
had to change the calibration on the MAP pressure channel on the EM2 to=20
get the correct reading (with EC2 on, we don't care what the sensor in=20
the EM2 is reading). =A0I have no idea why the calibration should be=20
different on different units that use the sam e sensor; but there it=20
is. =A0You can get a vacuum gage (actually a pressure gage, so you have=20
to subtract from atmospheric) at a reasonable price from McMaster-Carr,=20
or I could loan you mine.=A0

=A0

Also, it should not necessarily read the barometric pressure; you have=20
to adjust for altitude. =A0Barometric is equivalent sea level (or=20
something like that).

=A0

Al


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