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Date: Thu, 18 Jun 2009 19:06:41 -0700
From: Don Wallker <drwalker@gbis.com>
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To: flyrotary@lancaironline.net
Subject: responses to responses, not developing full power
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Flying RV-8 Renesis


List,
     Here is something new I noticed.  When running at 2450 RPM the 
other day, I switched off the Primary injectors and the engine continued 
to run, but it was rough.  I assume that this is a safety design 
feature?!  Tracy, am I correct on this?
    Another anomaly:  When running at full power, 5850 on so, on both 
injectors, about 5 or 6 on the mixture monitor, the EGTs stabilize at 
about 1640 F.  If I enrichen the mixture, I feel the power come on, 
about 50-70RPM, but the EGT on Rotor1 rapidly climbs to 1740 or so and 
the EGT on rotor 2 drops even faster to about 1450 F.  Off the top of 
his head, Tracy suggests that I am quenching the spark/combustion with 
too much fuel.  Thoughts and suggestions?
    Ed,
concerning manifold pressure (MP) on the EM-2,  I have added dampening 
and extra volume to the lines, with absolutely no difference.  The 
engine continues to run smooth too.  I conclude that the problem is 
electrical (noise?) and after the EC-2 is taking the info and processing 
it.
    The RPM goes to 0, not NOP, that's not NOP when switching off the 
primary or secondary injectors.  This problem was first noted in flight 
above 6000RPM when it would drop out to 0 and then reappear as the RPM 
dropped below 6000.   I added a 5K ohm resistor in series with the line 
to the EM-2 and a 47mfd cap to ground at Tracy's direction.  No 
difference.  My injectors are the stock Renesis,blue and red 295 and 495 
I think.  Cleaned and flow tested.  I also swapped them around to no 
avail.  Fuel flow on the EM-2 at full throttle is 11.5 to 12.5 gals. 
This is calculated on the EM-2 from the stock RWS original setting.  I 
believe that it is roughly accurate.
    Tracy,
I haven't taken the RV much out of the pattern, so haven't opened it 
up.  I don't want to overrun the Cessnas and Pipers and of course I am 
not yet confident in the engine.  After I make some progress on the 
instrumentation problems and a couple of other things, I'll button it 
up, do a few touch and goes and venture out and get the cruise info and 
see where full throttle takes me.  Airport altitude 5000 ft.  These 
number are from a 65 F day.  Yes, I believe the MP data is bogus.  The 
"both" on the original post means both injectors on and mixture at about 
6 or 7 bars.  Rich mean full rich.  I think the mixture monitor is 
reading correctly as best power seems to be at 7 to 8 bars. The manifold 
lines are both run to the front and rear of the plenum using a tee 
fitting..  There is no difference in engine running or the MP display if 
I run to just the front or the rear.  I have tried restrictions and 
accumulators to the lines and no difference.  I believe that it is 
electrical (noise?).   The temp sensor is mounted at the front of the 
intake to the oil cooler and the back side is insulated from the heat of 
the engine and coolers, exhaust, etc.  When coping A to B, I do it with 
everything off in the plane.  The procedure is dirt simple and works 
well for resetting to factory in all the other modes.  B controller 
would get me to an airport, but I would be paying close attention to the 
mixture monitor and adjusting the mixture with most power setting, MP 
changes.  I have run it in flight.  It will save my bacon, but I do not 
believe it is a copy.  It is just too different. 
Lynn,
I tried running at at less than full throttle, RPM per your suggestion.  
The throttle butterfly valve not all the way open..  I played with it 
some, changed the mixture, not difference.  So I don't think it is a 
burble or eddie in the intake plenum.  I have the throttle plate 
rotating on a vertical axis.

All for now,
Don Walker
N113BR