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