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Date: Mon, 06 Feb 2012 10:38:56 -0500
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Upper end tuning
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What coils are you using?  Steve mentioned spark plugs, but there was a
concern on the rx7clu8 mailing list that EDIS coils in a wasted spark
setup would saturate in a high RPM/high MP situation.  I've not run into
that, but a hard limit like that suggests that the coils might not be
able to keep up with what they are being asked to do.

Tracy wrote:
> Can't make an educated guess from the data given but here's a few
> questions & comments.
>
> Can you clarify what you mean by "precipitous power drop"?  Does the
> power go down at higher MP?  (6100 at 22.6" aint bad on a FP prop. 
> What was the airspeed & altitude?  EVERYTHING MATTERS!)
>
> Is the EGT imbalance only at high power?  Are you sure it's not
> instrumentation error?
>
> As Ed asked, what was the result of varying the mixture control at
> high power? 
>
> You say that engine is silky smooth below 6100.  Does that imply it is
> rough above 6100?
>
> The % power readout of the EM2 is meaningless if the fuel flow
> function isn't calibrated and you haven't plugged in a realistic value
> for your engine's max power.
>
> Tracy
>
>
> On Sun, Feb 5, 2012 at 10:01 PM, <bktrub@aol.com
> <mailto:bktrub@aol.com>> wrote:
>
>     I've got just over 20 hours on my plane today, all of the lower-
>     end bugs have been worked out. Right now I'm having power drop off
>     precipitously right at 6100 rpm- 22.6 inches of MP and around 70%
>     power according to the EM2. This is around 130-140 mph IAS. The
>     fuel injection Map shows a smooth graph at that point. I thought
>     that there might be a timing issue so I tried advancing the timing
>     about 2 degrees but that did not change a thing so I set the
>     timing back where it was previously. I am seeing about a 180 f
>     difference on the two rotors- I went to mode four to try to
>     balance out the egts, but I could only effect about a 20 degree
>     change. Rotor 2 consistently shows somewhere above 1800 F, which I
>     tend to question. I'll re-check my calibration.   I have had the
>     injectors cleaned and tested so unless one of them got clogged,
>     that should not be an issue. Still, I should pull them and have
>     them re-checked. I may have an issue with the EGT probes themselves.
>      
>      Down below 6100 rpm the engine is smooth as silk, but obviously
>     there is an issue above that .
>      
>      
>     Brian Trubee
>     RV-4  13 BREW
>      
>
>