Metrics on prop loading effects

Hi,

We had a recent sharing of prop-pitch change effects on EGT:

Quote:

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On Sat, Apr 7, 2012 at 8:52 AM, Raymond Henrie
<original_dr_doright@...> wrote:
> What do you mean? I can tell the takeoff is longer and the top speed is
> slower at the same throttle. . . . [my edits]

1) "Before the pitch change EGT would hit 1328 (720c) on cruise."
2) ". . . removed all but 1/2 degree that I added."
3) "Now temps at cruise run about 1292 (700c)"
4) "a small increase in climb will bring them down to 1256 (680c) or
even a little less"

You've shown a 36F/20C reduction from a 1/2 degree change in pitch.
I'm assuming you are still running the same 1/2 degree addition to the
prop pitch since it gives some margin on EGT. What is also important
is you've given some quantitative numbers of the drop:

1328F/720C - original
1292F/700C - new cruise with +1/2 degree
1256F/680C - slight climb with +1/2 degree

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Originally posted in the YahooGroup, Hirthflyers, this is the type of two-stroke metrics that re-enforces the Webinar: Is Your 2-stroke Engine About to Fail? - YouTube. Here is another data point that prop-loading is critical to two-stroke operation.

Bob Wilson