Mailing List flyrotary@lancaironline.net Message #41693
From: Al Gietzen <ALVentures@cox.net>
Subject: RE: [FlyRotary] Still fighting the good fight against the machine/rotary
Date: Fri, 29 Feb 2008 07:18:52 -0800
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

 

I am still having problems with Controller "B".  When I switch from A to B, the engine seems to want to stall, since the engine will not restart for a few hours (so far) after a run I flip back to A before this happens.  At higher RPM I can make the switch between controllers and it does not stall, but runs significantly rougher.  Could this just be due to the Auto Program refinements not yet being transferred to "B"?

Yes.  If you feel that the changes you have made on A are a definite improvement; do the A to B copy – mode 2, power off, hold the program button while turning power on, continue holding program button for a couple seconds.

 

Can you now display your mixture table? You may first want to review that and see if the profile looks reasonable – nothing that is clearly out of line with it’s neighbors.

 

When I disable the secondary's I did not notice any change in the way the engine sounded, but when I disable the primaries the engine would start to shut down...

If you are running below the stage point, the secondary are not on, so disabling them would do nothing. Turning off the primary I believe should cause the secondary to turn on; and if that shuts down the engine it would suggest that they are causing a much richer or much leaner condition. When you switch off the primary you could try to quickly richen or lean with the mixture knob to see if you can keep it running; telling you which way you need to go with mode 6.

 

Anyway, I decided to put this to the side for a moment and I pushed the throttle to WOT.  WOW, the temps rose pretty darn quickly at full throttle.....the temps were staying around 150 ish at idle and the lower RPM, but really soared at full tilt.  The displayed RPM on the EM are still jumping all over the place since I have not addressed this issue as of yet....flickers from 2000, to 4800, to 1200 back to 2000, to 4900 ish with a few numbers in what I think in the correct range predominating the various numbers.  I was a bit disappointed that the highest number I saw with WOT was only about 4999 ish.  Seems low.  Is the fact the engine only has a few hours on it and or is still not tweaked a reason for this, or is this expected sitting half in, half out of the hangar....yeah, the prop bit is outside in the sunshine <g>?

 

Yes, full power will heat things up in a hurry in a pusher where the prop blast is not assisting cooling.  Do you have an auxiliary fan on your rad?  I found I needed one.

 

Finally, for tonight anyway, back to the injectors.  After my data gathering run was complete I went to the diagnostic mode on the ECU.  When I tested the injectors as if they were firing at 3000 rpm I disable the primaries and could clearly hear the secondary's clicking away from inside the cabin.  When I disabled the secondary's I couldn't hear anything until I stuck my head outside the cabin.  When I went around to the engine I could clearly hear the primaries clicking away, but at a MUCH reduced volume of the secondary's.  Does this matter.  Do the two different types have this significant of a sound difference?  Could this explain the about mentioned shutting down with the injectors were turned off during the engine run?

It could be significant; but perhaps not.  Two different injector sizes, mounted in different places would likely make them sound differently. I wouldn’t be too concerned about max static rpm until you get the thing running properly over the range.  What size and pitch prop do you have?

 

Hang in there – these things take tenacity and patience.

 

Al

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