Some time ago I finally added a serial port to my engine monitor. Feeds serial port on my iPaq Pocket PC. I made a small Visual Basic  program that runs on the iPaq that logs the data to a text file.

Actually, I can connect my GPS output to serial input on the engine monitor. The program in the engine monitor sets MSBit to 1 on GPS data and merges it with the engine monitor data stream. The VB program then sorts each byte as either engine monitor data or GPS data. Doesn't work too reliably. Probably because the VB program is more like VB script (not compiled?) and runs too slow. You'll notice how the altitude column is very intermittent.
I thought about programming it in C, but the better solution is to use mode C encoder output and add an airspeed pressure sensor. As far as performance numbers is concerned we're interested in IAS or CAS and pressure altitude rather than ground speed and absolute altitude.

Finn

Ed Anderson wrote:

Good point, Finn

 

   I would just as soon not deal with non-linear output.  I'll check them out.  By the way, what do you use to collect your data? Laptop with a program? an A/D converter? both?

 

Ed

 

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

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

From: Finn Lassen

To: Rotary motors in aircraft

Sent: Saturday, May 22, 2004 3:42 PM

Subject: [FlyRotary] Re: New cooling Ducts

I like the LM34 or LM35 sensors (look up on google or Digikey), you get an liniar output mV/F or mV/C.

Thermistors are non-linear.

Finn

Ed Anderson wrote:

Yes, Bill, I recall our conversation.  I like the thermistor idea as the heavy wire required for thermocouples that I attempted was a real pain routing and connecting.  Now my question to you is what kind of simple data collector could I use to collect the output of the thermistor?  I presume I need some sort of A/D converter.  I do have a lap top if I just had the program {:>).  Any suggestion for thermistors, I know I could probably figure it out, but if you have any suggestions based on experience, I would like to hear it.

 

Since I don't intend to change the duct attachment scheme to radiators, I can always place any combination of old and new ducts on the aircraft (hopefully). 

 

Ed

 

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

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

From: William

To: Rotary motors in aircraft

Sent: Saturday, May 22, 2004 9:44 AM

Subject: [FlyRotary] Re: New cooling Ducts

Ed,

Since you are building two new ducts, I would like to propose that you also install the thermistors so you can do the following set of tests (briefly mentioned at SNF).  Basically at a steady power setting in flight, and potentially at different air speeds, measure the following temperatures:

Tin left, Tout left , Tout right

 

1. With your *current setup*, with one reshaped duct and one original duct.

2. With your current left duct and one of the new ducts, and

3. with both new ducts.

 

Since you are plumbed in series, and have identical rads, this will give us information on the performance of the ducts.

Bill Schertz
KIS Cruiser # 4045

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

From: Ed Anderson

To: Rotary motors in aircraft

Sent: Friday, May 21, 2004 6:58 PM

Subject: [FlyRotary] New cooling Ducts

Well enough of that, since the new C drive will apparently enable the engine to turn 1000 rpm higher, I decided that was good enough reason to finish my experiment with the cooling duct that turned out well.  Rather than filling in the other duct with expandable foam, I've decided to build two new ducts with the proper curve built into the walls.  So will be using the Streamline coordinate system (modified).  Since there is not enough space for the full distance, I will truncate the streamline coordinates as I did on the test duct.  Consultation with the gentleman who wrote the excellent article on liquid cooling in the January 2004 Sport Aviation and my own test  indicated   that as long as the duct was truncated from the inlet end, the adverse effects on airflow should be minimal.

 

So, will get started on that probably next week early.  Got the coordinates laid out in my old Cadd package only to find out that its printer drivers will not drive the new HP printer I recently got.  So I guess I'll try converting the CADD to a DWG file and go to one of the CADD packages I acquired over the year but never really used to see if they have the correct driver. One thing or the other.

 

 

 

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC