I have been working
with staging for a couple of days and have my normal confusion.
I have the Renesis
engine but I have changed the red primary and blue secondary injectors to all
yellow injectors. This gives me roughly the same fuel flow capability
when all four injectors are on, but a higher flow capability when only the
primary are on as compared to the normal Renesis.
My staging point is
set at 15 inches. I know that is lower than Tracy recommends, but it
reduces the cooling requirements while I mess with it. I may change it
later if I figure out what I am doing and get better (faster) at fixing the
settings.
If I have the
manifold pressure above the staging point and slowly lower it, it is a smooth
transition and there is no indication that I can see or hear that the staging
has changed. BUT!
If I have the
pressure below 15 and slowly raise it, it seems to me that the engine is
trying to make a decision as I go above 15, until I get to about 15.5, then it
suddenly makes a different sound and jumps to 16.0-16.5. These bins are
about 43 or 44 at 15 inches and it always jumps to 47 or 48. The map
table levels in this area are close to the same.
I have not been able
to determine if the change need is to lean or richen the mixture. If you
read the study Steve did, it would seem that it needs to
richen??
I tried a suggestion
I read of Tracy’s…I checked the fuel flow just below
the stage point, 2.7 gal/hr. then above the stage point.4.1 gal/hr.
This caused me to conclude that I needed to lean it, so I lowered
it back down below the stage point to get started trying it and Whups! The
fuel flow was still at 4+gal/hr! I waited for it to lower but it
didn’t???
I realize this sounds
like I am rambling…..so what else is new!
Any insights would be
welcome.
Bill
B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Ed Anderson
Sent: Saturday, November 06, 2010 9:38
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Staging Adjustment
in EC2 since 2006
Pertaining to Steve's data and
analysis and Tracy's comments about Mode 6 of the
EC.
I went back and read up on the Ec2
modes and found this statement which I had apparently not paid sufficient
attention to, but in light of Steve's data and findings, thought it might be
pertinent to the discussions. From the EC2 instruction
Manual:
01-07-06
update.
Because the rotary has two
injectors per rotor and they are staged (see Mode 7 for details on staging),
it is possible that the mixture
might be
miss-matched differently when staged or not
staged. You may have to match the EGTs once when
the engine is staged
(low power) and again when
not staged (high power).
So it appears that the EC2 has had
the capability to adjust the different in flow rates across the staging event
since at least 2006. But, perhaps
like many others, I was not certain what conditions would signify this
needed adjusting (until Steve's data and analysis) and therefore
never attempted any adjustment (my dumb!) - my philosophy being if it is
working well and you don't have a clue as to what/why you are adjusting
something - then DON'T! {:>)
The only "problem" (actually more
of an irritant than a problem) I have ever encountered using the EC2 was
the staging "bog" I would encounter while operating on the ground which I
finally eliminated. What I did was to enrich the fuel MAP in the
3-4 bins in the High MAP region that the engine point jumped to after
staging. This did solve my staging bob - but, after reading the
EC2 instructions again, I can see that if I probably should have used Mode 6
to accomplish this as my adjustment was just for 3-4 bins and not all
bins.
Once again Tracy has addressed the
need in the Ec2/3 - but, I just failed to understand the function (and
conditions) it might have addressed. Now that Steve has clearly shown
there is a high probability that adjusting the staging flow rate will result
in more accurate fuel totalizer values and other fuel factors, I can now
see a reason to use mode 6.
Thanks, guys - discussions on this
list is generally always educational and helpful
Ed