Message-ID: <000901c41b02$d56f9240$2402a8c0@EDWARD>
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-3145988@logan.com>
Subject: Re: [FlyRotary] fun  with EGT's
Date: Mon, 5 Apr 2004 07:40:45 -0400
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Perry,

    I have had two engines and two sets of EGT probes and in all cases I
have a 75F-125F difference between the two rotors.  It varies, they are in
Sync up to around 1200F then they start to diverge.  There is approx. a 2"
difference in the pipe location of the sensor.  But one pipe has a 45 deg
bend before the sensor and the other does not.  I speculate that perhaps the
bend diverts the main core of the hot gas away from the one sensor during
high power operation (more, faster? exhaust flow), but not during idle and
low rpm operation?

   To make a long story short, after trying many of the same things you did,
I just gave up since I could never detect any adverse effect.

Ed

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message ----- 
From: "Perry Casson" <pcasson@sasktel.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, April 05, 2004 12:10 AM
Subject: [FlyRotary] fun with EGT's


> Hi All,
>
> I've been fighting with a problem getting my EGT's to staying more or
> less equal but I'm running out of ideas of what might be wrong.
>
> At idle to about 4600 RPM the EGT's are +/- 20 deg. and go from 1100 to
> 1500 deg.  after that as power is increased rotor 1 will go up to 1820
> or more and rotor 2 will max in the mid 1600's (my max static is about
> 5300rpm).  I've tried re-calibrated injectors in all four spots with no
> change.  I can disable either pair of injectors and run all the way to
> max static rpm of around 4300 with just one pair enabled and the temps
> stay in sync so I'm fairly sure the injector flow is reasonably well
> matched.  I've tried several times in flight to use EC2 modes 4 & 5 to
> balance the temps and I can get them fairly close  in my cruise settings
> of 4800-5600 rpm but the engine will then run real rough at lower
> throttle settings.   One thing I'm wondering about is with my exhaust
> system the length of the header pipes is about 3" longer on one pipe
> than the other, is it possible that one rotor  is coming into it's tuned
> band and causing it to go leaner and hence a 150 deg temp diff?  The
> tuned exhaust theory almost holds water except it's the rotor with the
> shorter pipe (rotor 1) that is running hotter and I would be expecting
> it to be the other pipe that would get to it's tuned length first.  Any
> one else seen this sort of thing?
>
>
> Perry Casson
> Glastar/13B  - 13 hours
> http://eaa154.dhs.org/perry
>
>
>
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>