----- Original Message -----
Sent: Saturday, November
06, 2010 9:32 AM
Subject: [FlyRotary] Re:
Staging Adjustment in EC2 since 2006
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