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From: "Bill Bradburry" <bbradburry@bellsouth.net>
To: "'Rotary motors in aircraft'" <flyrotary@lancaironline.net>
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Subject: RE: [FlyRotary] Single lever control
Date: Thu, 6 Sep 2012 10:34:13 -0400
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Earnest,

If you were in the pattern and reduced power to the point where you were at
half throttle or below and the mixture then went to "near cutoff lean" it
seems you would be in danger of the engine stopping.  That might not be a
desirable thing when you are that low to the ground even if you were in a
pattern...??

Bill B

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Ernest Chrisltey
Sent: Thursday, September 06, 2012 10:19 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Single lever control

This is what I was referring to in my previous email.  Throttle is 
graphed against RPM in both.  On the left, data points are colored based 
on coolant temps at the time the data point was captured.  The right 
graph uses AFR to set the color.

The one on the left has the points colored according to coolant temp at 
the time the data point was collected. This graph tells me that a cold 
engine will make more power.

The right graph has the points colored according to AFR, and is more 
interesting. My throttle plate is fully open at about 50% travel of the 
control lever.  My goal is to keep the mixture near cutoff lean until 
after the throttle plate is wide open. Until WOTP (wide open throttle 
plate) power increases from increasing the amount of intake charge. 
After that, pushing the lever forward increases power by enrichening the 
mixture.  I transition from changing the amount of mixture, to changing 
the makeup of it.   I would like a solid diagonal line, correlating 
throttle and RPM.  The graph shows me that I reach best power mixture to 
quickly.  I need to shift my target AFR a bit so that the lines flatten 
out with only 5% to 10% of lever travel left;  however, for the most 
part I've achieved the goal of having RPM directly correlated with 
throttle position.