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Thanks all for the power setting information.-- Now comes the additional
situation of tweak leaning the engine (ec-3 and em-3) once leaning is desired.
Of course my concern with this, and the engine speed is Knocking and possible
destruction of the apex seals. The Renesis in the car has a knock sensor
which, I assume, protects the engine in times of hard knocks. However we do not
use this sensor (I think that that was one of Tracy's future projects before he
had the audacity to retire on us  (enjoy your well disserved
retirement Tracy).
I know that the rotors are bullet proof, to a great degree, but knocking
can, I think, damage the seals and then the trochoids.
What say all of you
Leaning shy as aggressive leaning on a Lycoming IO 540K1E5 necessitated a
top chrome overhaul at 350 hours since new  . (years ago when things were
much cheaper)
Rich
In a message dated 6/8/2015 10:20:26 A.M. Central Daylight Time,
flyrotary@lancaironline.net writes:
Bobby,
Wouldn’t you think
that equates to about 250 hp on take off??
Bill
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Monday, June 08, 2015 9:47
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: new operating
question
Bill,
I believe my
normal fuel flow is actually closer to 23gph at 7000 rpm\ 38” MP and 12.5 FA.
I don’t really look at it anymore during takeoff. I’ll pull current engine
logs when my AFS-3400 EM gets back from repair. It decided to start rebooting
every few minutes. I can run 40.5” MP / 7500 rpm at sea level but avoid
the top limits. My MT controller is within 100 rpm.
Bobby
From:
Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Monday, June 08, 2015
8:46 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: new operating
question
Bobby,
You can take my fuel
burn numbers with a grain of salt. The EM-2 is not completely calibrated
for fuel flow.
By the way, is your
prop controller dial calibrated to the prop rpm you actually get? Mine
is not and I think that Mark’s may not be either based on some of the things
he has written.
To get 7100 engine
rpm, which is 2500 prop rpm, I have to set the controller for 2600 for
takeoff. 2400 setting will get me 6500, etc.. Early on, I thought
that the tach on the EM-2 might be off, but I decided that to be pretty
unlikely. However, there is a disconnect between the
two.
Bill
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Monday, June 08, 2015 7:01
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: new operating
question
12 gal/hr for takeoff sounds extremely low. I'm closer
to 25.
I leave the prop in automatic mode all the time.
I set the prop to go around rpm on downwind. 2300 / 6500 works well for me and
almost eliminates air breaking during short final. I try to carry a small
amount of power through the flare but I think that's common with RV's. I had
to really work on slowing down before entering the pattern and adjusting the
prop to 2300.
Charlie,
I am flying a
Lancair Legacy Fixed Gear. I burn 8.5 – 9 gal/hr at cruise and a
little over 12 on take off. I don’t have my fuel flow calibration
completed and it could be part of a gallon or so off on the EM-2. I get over
20 mpg at over 185 mph which I still have trouble getting my head
around! In a car going that fast you would be measuring it in
gallons/mile! I really never tried to lean the engine before I
put the broadband sensor in the plane so I don’t really know the answer
about the egt spread. I do get a lot higher egt readings than were
advertised. I was expecting temps in the 15-1600s, but they are in the
1700s.
Since the rotary is
so sensitive to rpm for power output, I don’t know if I would have been
happy with it with a fixed prop unless I had more power than I needed.
I have seen two MT props for sale since I bought mine and both were good
deals. I highly recommend the electric prop. It responds a
little slower than a hydraulic prop, but that is only a problem if you slam
the throttle. I guess the other con for the prop is it helps to carry
some power to touchdown because if you chop power in the flare, the prop
goes flat and acts like a big brake and the plane seems to just stop flying
and drop. I carry power, but I think Mark switches the prop to manual
in the pattern and lands it like it was a fixed prop. I don’t know
what Bobby does in this case.
Bill
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Sunday, June 07,
2015 7:14 PM
To:
Rotary motors in
aircraft
Subject: [FlyRotary] Re: new operating
question
Hi Bill,
I'm always hungry for 'numbers' like
that. Can you refresh my memory on which plane you're flying?
What's
your fuel flow during takeoff?
And I'm really interested in your fuel
flow at your cruise setting of 6000 rpm full throttle up at 7500-8000 feet.
Do you have an EGT in addition to your f/a gauge? If so, what's the egt
spread between peak and leaned to your cruise setting of 16-1 f/a ratio (how
many degrees lean of peak)?
Having a controllable prop certainly
makes it easier to get a full set of performance numbers, doesn't
it?
Many thanks,
Charlie
On 6/7/2015 2:59 PM, Bill
Bradburry wrote:
Rich,
I am flying the
NA Renesis with MT electric prop and wideband O2
sensor.
Take off and
initial climb is WOT with 7100 rpm, after about 500 ft AGL, I dial the
prop back to 6500 rpm, still WOT. Cruise climb is WOT and 6000-6200 rpm,
and cruise is WOT and 5200-5800 rpm. All climbs are at 12.0-12.5 F/A
mixture and cruise is 15.8-16.0 F/A mixture.
I never move the
throttle off of wide open until I am slowing to enter the pattern for
landing. Engine speed is controlled with the prop and power to some extent
with the mixture.
I have hopes that
after Bobby makes his decision as to whether to go with the turbo or the
20B, he will give me the other one! :>)
Bill
From:
Rotary motors in
aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Sunday, June 07,
2015 10:25 AM
To:
Rotary motors in
aircraft
Subject: [FlyRotary] Re: new
operating question
My normal, not in a hurry settings.
38" MP / 7000 rpm for takeoff and initial climb
with F/A 12.5-12.0. Cruise climb 5800 rpm 30-32" MP F/A 13.5- 12.5.
Preferred cruise rpm 4800- 5200 At less than 30" MP and F/A 15.8-16.0.
Full throttle. Prop rpm controls engine rpm and super charger bypass
controls MP. A turbo charger and automotive waste gate would likely
require throttle management during high rpm operations.
Super charged Renesis with electric MT
prop.
(New Turbo charger and a 20B on the bench- still
haven't made a decision about upgrading the RV10.
)
Greetings genlepeople of the
rotary pursuasion,
For those of you using
variable pitch (C/S) props, an operating question that has been bugging
me. Perhaps the collective wisdom of this group can set my mind at
rest.
In piston aircraft engines,
the concept of running over squared MP vs RPM has been heavily
questioned to the extent that some suggest running at full throttle all
the time and controlling the power output via RPM (within reason). The
thought is to, I believe, eliminate the induction restriction of the
butterfly valve increasing the
efficiency.
Now we have a rotor
spinning, a gear box gearing and a propeller propelling. Does this
concept hold true for the rotaries. What are people doing in terms of
setting power after take off (full throttle max
RPM).
My enquiring and rotating
mind wants to know.
(Unturbocharged Renesis with
RD1-c Box)
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