Mailing List flyrotary@lancaironline.net Message #23199
From: Mark R Steitle <mark.steitle@austin.utexas.edu>
Subject: RE: [FlyRotary] Re: Tracy, EM-2 question
Date: Mon, 6 Jun 2005 14:11:26 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Bill,

I should have consulted with Tracy before I went down this road myself.  Anyway, I just installed redundant senders for oil, coolant, and fuel.  Temp sensors are very lightweight.  Pressure sensors are just a tad heavier.  I didn’t get the extra data board on my EFIS, so EGT’s & CHT’s are on the EM-2 only.  Since the weight penalty of the EFIS-1 has already been paid, I figured why not go with engine instrument redundancy.  The only one I’m not satisfied with is the engine RPM on the EFIS-1.  It doesn’t agree with the RPM readout on the EM-2.  Until proven otherwise, I’m assuming the EM-2 figure is correct.  Once I get the prop installed and can run it without fear of overspeed, I can put a prop tach on it and know for sure.  Then I can calibrate the EFIS-1 RPM’s.  Be sure to calibrate all sensors! 

 

Mark S.       

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Monday, June 06, 2005 1:53 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Tracy, EM-2 question

 

Hi Bill,

Unfortunately there is not a simple yes or no answer to the sensor connection question.  Voltage output sensors like the OAT, AUX 1 & 2 air temp sensors and CHT / EGT  can be hooked to several systems at the same time but variable resistance sensors like the water & oil temp & pressure sensors can not.  The EM2 fuel level inputs were designed to be used in parallel with Van's Aircraft fuel tank gauges.

 

The EM2 can measure tach speed in two ways.  The default scheme is to look at the rep rate of the fuel injector pulses.  This could be used by multiple systems.  The other method is to use the serial engine data from the EC2 and calculate RPM from one of the parameters in that data.

 

Greg at Blue Mountain had requested the EC2 protocol (I sent it) and was going to build in an interface to the EC2.  I doubt that he has had time to do that though.  There is only a tiny number of his customers that would use this.

 

Yes, you have the switch type for the coil disable switch correct.

 

Tracy

 

Subject: [FlyRotary] Tracy, EM-2 question

 

Hi Tracy,

EM-2 and upgraded EC-2 arrived Saturday. Thanks,

 

A question:

I am installing the Blue Mountain EFIS-1 in addition to the EM-2. The BMA will allow logging of some of the engine parameters for later analysis.

 

I believe you are planning on a BMA/EM-2 combo in your RV-8 also. It is my understanding that I cannot hook a temperature or pressure probe to both units, is that correct? What about Tachometer connections?

 

EC-2 question: I apparently lost the coil disable switch supplied with the EC-2 back in 01 when I originally received it. I interpret the drawings/schematics as the switch being a (on)-off-(on) switch (springloaded to center off position, with momentary on positions both ways). Just want to verify that before I order a matching switch to my others.

Bill Schertz
KIS Cruiser # 4045

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