No, I don’t think you
are wrong about mode 6. This part of the instructions are what I was
referring to:
Keep the throttle setting at this point
(above staging point) and repeat this step until the mixture monitor indicates a
mid-scale reading
In your earlier post you said move below the staging
point to make the change. The above suggests we should stay above to make
the change. In a previous post, I think Tracy commented that the mode 6 only affects
the injectors above the stage.
Tracy’s instructions seem directed to leaning (I think)
because if you are transitioning from small primaries to large secondaries, you
will need to lean. But according to Steve’s study, if you are
transitioning from same size primaries, you will have to richen. This kind
of info is a great help for me because I have trouble trying to figure out which
way to go when the engine is stumbling.
Bill B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Ed Anderson
Sent: Saturday, November 06, 2010 12:24
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Staging Adjustment
in EC2 since 2006
I could be wrong about Mode 6 - here
is the description out of the manual - plus Tracy indicated in a recent e mail that Mode 6
was designed to address the situation that Steve found with his data. My
comments in blue
Program
Mode 6 (Secondary injector differential adjustment)
Some of the
Mazda rotary engines produced after 1989 (especially the 2004 and later Renesis
engines) had larger injectors for the
secondaries. This will result in an overly rich mixture above the staging
point (this is clearly not your situation)
since the EC2 assumes that all the injectors are
the
same size
(flow rate ). If your engine is equipped with larger secondaries, Mode 6 can be
used to balance the
mixture (note the word used is
balance - not restricted to leaning) above
the
staging
point. It is also suggested that the staging point be set higher when using
large secondaries. A setting of about 19” Hg
MAP is a
good starting point.
If you need
to adjust for larger secondaries, follow these instructions. This should be
performed immediately after you have
checked the
Mode 3 setting and adjusted it if necessary (see Mode 3
instructions)
1. With the
engine running below the staging point, (I would suggest about 14 – 15” Hg
manifold pressure) and the mixture
monitor
indicating mid scale, select mode 6 and turn the program knob slightly to the
left of 12:00 position ( for leaning) and press the
program
store
switch. Now advance the throttle to above the staging point (~ 20” Hg ) and
observe the mixture.
2. If the mixture goes richer, turn the program knob a little
further to the left and push program store again. Keep the
throttle
setting at this point (above staging point)
and repeat this step until the mixture monitor indicates a mid-scale reading.
If you go
too
far and the mixture
goes lean, turn the program knob a little to the right and hit program store
again. Keep making
small
adjustments until you get a mid-scale
mixture reading.
The instructions I have in red
indicate to me that although designed with larger secondary injectors being the
driver for this mode and therefore the focus for the description, that in this
mode you can be used to adjust (balance) for a differential in flow either way
- leaner OR richer. Now clearly that is my interpretation and
I will admit could be incorrect.
Ed
Sent: Saturday,
November 06, 2010 12:08 PM
Subject:
[FlyRotary] Re: Staging Adjustment in EC2 since
2006
Ed,
I agree with your take
on the problem being a lean after staging problem. This was where I was
really confused.
I think tho, that the
mode 6 only works above the staging point and affects the injectors when all are
operating. I think I should get the mixture set at mid range below the
staging point, then move to above the staging point and see if the mixture goes
lean. If it does, I should stay above the staging point, set mode 6, set
the program knob slightly right of center and hit the white button. If
this doesn’t bring the mixture to center, move the program knob further right
and hit the button again, continue till the mixture is in. all this done
while above staging.
A lot of my confusion
is related to getting indications that it was lean and rich using two different
techniques. I haven’t tried to calibrate the fuel flow, but I am confused
by the fact that it didn’t change back after I dropped back below the staging
point.
I also think that
changing the injector flow with mode 6 will cause all the map table above
staging to have to be changed (lowered? in this
case).
Bill
B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Ed Anderson
Sent: Saturday, November 06, 2010 11:23
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Staging Adjustment
in EC2 since 2006
Here is my take for what its
worth.
Your description (and flow values)
sounds like you are encountering to what I refer to as "staging bog", in
my case, during the staging event my air/fuel ratio indicator would disappear
off the lean end of the scale and the engine would momentarily stumble. I
ended up enriching those fuel bins (in my case bins 67-72) that my pointer jumps
to immediately after staging - the bog disappeared. So in line with what
the EC2 manual states and Steve's findings, it would appear that some
enrichment may be needed.
Tracy indicated in his recent e mail that
Mode 6 could be used to address the "flow rate" from below staging point to post
staging point of operation. Now the description of this mode in the EC
manual indicates it was apparently designed for those situation where
folks used a different (larger flow rate) injector in the secondary
positions. However, Tracy's suggestion to use it to compensate for
a needed difference in flow rates (increase or decrease) across the
staging point makes sense to me.
Its is suggested that you use your
Air/Fuel Ratio indicator to determine which way to adjust using Mode 6. It
sounds like in your case, you need to enrich the flow after staging rather than
lessen it. So taking the opposite approach to the description in the Ec2
manual (which was adjusting the staging so it went leaner after staging), it
would seem you would get below your staging point (so only the primary injectors
are operating) and enrichen the mixture using mode 6 and using the Air/fuel
ratio indication to see the results. Then advance your throttle so you go
above the staging point - and see if that has improved the situation. If
not enough, then drop back below staging point and again increase the mixture
with the Program Mixture knob greater than 12:00 enriching the mixture and then
take the engine back above the staging point.
I believe this is essentially what I
accomplished (enrichen the flow) by manual adjusting (increasing) the MAP values
in the bins my engine jumps to after staging.
The reason you don't get the bog
dropping down ( in my opinion) is you are going from a leaner flow (above
staging) to a richer flow below staging - therefore no bog. But, going
from a richer flow to a leaner flow during staging causes you engine to
"bog".
Others may have different
suggestions.
Sent: Saturday,
November 06, 2010 10:32 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