Rotating Injectors Among Cylinders

Interesting thread. I was inspired to do a bit more analysis on the
data I have been collected. Here is what I found.

Cyl #5 peaks first at 12.5 gph fuel flow
Cyl #6 peaks second at 12.0 gph
Cyl #4 peaks third at 10.5 gph
Cyl #3 peaks fourth at 10 gph
Cyl #1 and #2 do not seem to reach peak even down to 9.5 gph

That seems like a pretty significant range. Does this suggest a
specific problem I should have my A&P look at?

My manual talks about 2 modes of operation, best-power at 100 deg ROP
and best-economy at peak. There is such a difference between cylinders,
it is hard to know where to set it.

For example, if I use cyl #5 to lean (at a given altitude and set of
conditions), when it is at peak, the other cylinders were at:

#1: 80 deg ROP
#2: 60 deg ROP
#3: 50 deg ROP
#4: 30 deg ROP
#5: 0 deg ROP
#6: 0 deg ROP

If I use #5 to set to best-power, 100 deg ROP, then the other cylinders
were as follows:

#1: 190 deg ROP
#2: 185 deg ROP
#3: 160 deg ROP
#4: 130 deg ROP
#5: 100 deg ROP
#6: 85 deg ROP

Neither of these seems very satisfying.



O. Sami Saydjari wrote:

My per-cyclinder avg EGTs are as follows:

#1: 1370
#2: 1390
#3: 1450
#4: 1450
#5: 1480
#6: 1430

The difference is 110 degrees between the coldest and hotest cylinder. A
colleague of mine says that is a bit high for a fuel-injected system.
Is that right?

He suggest rotating the injectors from the hotest cylinders to the
coldest ones to try to better balance them (so, for example, swapping #5
and #1). I am not sure why one would do that. Have others done that
with success?

-Sami
N2057M, Piper Turbo Arrow III

O.,

Does this suggest a
specific problem I should have my A&P look at?


I think you should talk to Gami.

--
Thomas Borchert (EDDH)