Hi Chris,

Just wanted to mention that when you used the "Injector Disable" switch to
turn off the primary injectors - the EC2 will then automatically turn on the
secondary injectors regardless of whether you are above or below the staging
point. They in effect become your primary injectors.   This is assuming you
have the injector switches wired per Tracy's recommendation and of course
the "disable" switch is ON for your secondary injectors.

So assuming your EC2 is set up properly the engine should idle on either
pair (with perhaps some minor tweaking of the mixture control).

Does sound like your cooling system is doing the job in the Texas heat.

Regarding the wire.  20 AWG stranded wire has a DC resistance of approx 10
ohm/1000 ft, the 16  approx 4 ohm/1000 ft

So that would give you approx 0.15 ohm for your 15 foot run compared to 0.06
ohm if using the 16 gauge.  Assuming you had 10 amps flowing through the wire the 20 gauge would give
you a voltage drop of 10 * 0.15 = 1.5 volts.  For the 16 gauge it would give
you a drop of 10 *.06 = 0.6 volts drop.  Now whether this is significant or
not depends on the application.  Haven't looked at the wiring diagram, but I
presume this 16 gauge wire is going to your injectors - if so, then you have
the additional factor of a very fast rise time pulse signal being on the
wire, the effect of the different size wires on the signal is harder to
assess.

BUT, if the circuit is critical to flight, then I would be inclined at some
point - before first flight to install the called for size.  Tracy generally
does not make such decisions regarding such things (as wiring size) without
having given it some thought.  I would hesitate to second guess him on that.
It may work just fine as is - but "may" is not good enough in my book for
any flight critical aspect.

Check that your O2 sensor is properly grounded - some have two, three or
four wires and its important that they be connected properly. The O2 sensor
is only putting out less than 1 volt, so needs a good electrical ground.  In
a composite airframe, IF your exhaust pipe is somewhat insulated (by gasket
or sealant) from your engine block then it may not have a good electrical
ground.  You might try temporarily connecting a wire between the exhaust
pipe with the O2 sensor and a good electrical ground in the engine
compartment and see if that makes any difference.

Good luck, sounds like you are continuing to make progress.

Ed


Ed

Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.rotaryaviation.com/Rotorhead%20Truth.htm


-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Christopher Barber
Sent: Saturday, June 27, 2009 2:40 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] More progress, more questions....

Back out at the hangar today and some real progress made.

Even though I am still having to "pump" the throttle to get the RPM down after having the throttled advanced, I do have the rpm and manifold pressure down.  I cannot find a leak, HOWEVER, when y'all (Bill I think) mentioned my new injectors it dawned on me that I installed the new injectors and then cranked it pretty much right up to see if it would even start.  From there I started playing with it.  I had meant to reset everything and start anew. However, I got caught up in the process and never got back to a base.  So, today I reset the EC2 to the factor setting and started it up and it ran even better.  Did the Mode 3 (at 22 inch manifold pressure), 6, 2, 1 thing.  The engine is running better than ever.  I have the manifold pressure in the 12 range.

I am concerned about some sputtering that is present around idle.  It is generally pretty smooth, but sputters too. Not sure what is causing it yet.  Thoughts?

I still have some inconsistencies.  Today, I was running the engine at idle and everything seemed fine. It was idling at about 1500 rpm.  I looked away and when I looked back, the rpm was reading about 3300 rpm.  Nothing had changed and the engine was still running at idle but the rpm was showing 3300, MP was 12.7.  I increased the throttle to see what would happen and the rpm shoot up to 8000 rpm.  What the hell?  I kept playing with the throttle and it continued.  I shut down and restarted and it continued.  Shut down again and grabbed a soda, came back and fired it up and it was showing normal again.  Hmmmmm?  I checked grounds but am not sure which wire to check...guess the one for the tack, but it is difficult to check when it goes away on its own.  DOH?  I will have to keep an eye on it.

Also, even when the MP is below 15 and the secondaries should not be on, if I shut down the primaries the engine still runs.  Shouldn't it quit if I turn off the primaries since the secondaries should not kick in until the staging point?  Maybe this is too basic, but what am I missing.  Do the secondaries turn on automatically if I turn off the primaries as a safety featur????  It seems as if I may have read this somewhere, but I am not sure. I know the switch to the primaries and secondaries are wired correctly for the power and do not understand why they would run when power is removed.

Next, in the documentation for the EC2, the diagrams and part of the text it shows that most of the wires should be run using 22 and/or 20 AWG wire for the connections.  However, in ONE place in the document it states that the power wire to the coils should be 16 AWG.  Dang, I just rewired these down a special conduit using 20 AWG.  Do I need to redo them with 16.  My concern is whether the larger wire will fit down the tube.  I am not sure what is the most current documentation (btw, they differences are in the same manual)  Currently the 20 seems to be working well and I would prefer not to have to change them again, however, I do not wish to have a potential problem looming that surely will be easier to remedy now than later.  This is about a 15 foot run in the Velocity. BOB?

Finally, for today anyway <g>, while my EM2 seems to be giving me good solid data, I do seem to have a problem with my mixture indicator.  The little bar graph jumps all over the place and gives me no real solid indication.  While I am pretty good at tuning by ear, it kinda defeats the purpose to have this great technology to be able to get some precise measures, if my key indicator is not giving me what I need.  I have of course checked the wires and even replaced the OXY sensor in the exhaust.  Thoughts.

Oh, a final comment on progress.  My cooling continues to impress me. The bigger rad/fan and oil cooler is able to idle and even take some power for some amount of time allowing me to fiddle with things.  To REALLY illustrate the point, take a gander at the attached jpeg showing the ramp temperature this fine Houston afternoon....ok, in case you cannot open the file, it was 112.5 on the ramp and 100 in the shade.  I was still cooling <g>

Also, here is a shot of the weird RPM, being much higher than is should be, with a low MP.



Thanks guys and gals.

All the best,

Chris



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