Are you off racing again {:>)?
Ed
Sent: Sunday, May 15, 2011 5:02 PM
Subject: [FlyRotary] Re: Engine Tuning/Tracy?
There have been a lot of refinements in the past 5years but whether the CAS
impedance matching I mentioned will fix your issues is beyond what I can
predict.
Tracy
Sent from my iPad
So Tracy, I'm going to do another ground run and record all the MAP
data/engine RPM etc.. The plane flies well, I just want to nail this engine
running issue down. The last update on my EC2 was 4-19-2006. Do I
need another update, or to change my trigger wheel or CAS sensor/s?
Brian Trubee
-----Original
Message----- From: Tracy < rwstracy@gmail.com> To: Rotary
motors in aircraft < flyrotary@lancaironline.net> Sent:
Sun, May 15, 2011 5:03 am Subject: [FlyRotary] Re: Engine
Tuning/Tracy?
Yes, there is a big difference. The Renesis has a totally different
trigger wheel pattern and only one sensor. The sensor itself is very
similar though. It may need the Renesis impedance matching network that
is built into the EC3 and added into 13BREW EC2s when necessary. Some
installations have needed it, others have not.
The symptoms typically happen at higher rpms and not below.
Tracy
Sent from my iPad
Ok Tracy,
This is a new one to me- is there a functional difference between the
sensor wheel and two crank angle sensors on my 93 BREW and the
Renesis?
I'm not seeing any problem up to about 5300-5500 static. It's in the
air that I'm having problems with missing and backfiring.
Brian Trubee
-----Original
Message----- From: Kelly Troyer < keltro@att.net> To: Rotary motors
in aircraft < flyrotary@lancaironline.net> Sent:
Sat, May 14, 2011 10:14 pm Subject: [FlyRotary] Re: Engine Tuning
Brain,
That is a question Tracy will have to answer...........I
was not (or just did not ever hear)
of anyone using the EC2 with the 13BREW 2 sensor
system..............
Kelly Troyer "DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine "RWS"_RD1C/EC2/EM2 "MISTRAL"_Backplate/Oil
Manifold
"TURBONETICS"_TO4E50 Turbo
From: "bktrub@aol.com" <bktrub@aol.com> To: Rotary motors in aircraft <flyrotary@lancaironline.net> Sent: Sun, May 15, 2011 12:10:08
AM Subject: [FlyRotary] Re:
Engine Tuning
No, I am using the stock 93 13BREW timing wheel and two crank
angle sensors- one senses every 30 degrees and the other senses once per
revolution, I presume. There's a difference? What is it and how does it
effect the ignition system?
Brian Trubee
-----Original
Message----- From: Kelly Troyer < keltro@att.net> To: Rotary motors
in aircraft < flyrotary@lancaironline.net> Sent:
Sat, May 14, 2011 10:05 pm Subject: [FlyRotary] Re: Engine Tuning
Brian,
You are using the Renesis timing
wheel and single sensor rather than the
93-95 13BREW wheel and dual sensor system I
presume...........
Kelly Troyer "DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine "RWS"_RD1C/EC2/EM2 "MISTRAL"_Backplate/Oil
Manifold
"TURBONETICS"_TO4E50 Turbo
From: "bktrub@aol.com" <bktrub@aol.com> To: Rotary motors in aircraft <flyrotary@lancaironline.net> Sent: Sat, May 14, 2011 8:59:15
PM Subject: [FlyRotary] Re:
Engine Tuning
So Mark,
your CAS was one of those that are configured like a conventional
distributor before you changed it?
I'm going to go out to the airport and do some ground running and I'll
report back with the Map table values and what kind of rpm and map address I
get at WOT.
Brian Trubee
-----Original
Message----- From: Mark Steitle < msteitle@gmail.com> To:
Rotary motors in aircraft < flyrotary@lancaironline.net> Sent:
Sat, May 14, 2011 4:35 pm Subject: [FlyRotary] Re: Engine Tuning
Brian,
My ignition problem was only evident at 5800 rpm and up. It ran
fine below 5800. I could get there on the ground since I have an
adjustable prop. Maybe you could borrow a smaller prop so you could
replicate the problem on the ground?
Mark
On Sat, May 14, 2011 at 6:31 PM, <bktrub@aol.com> wrote:
I've got the crank angle sensor mounted on the crank pulley. I don't
have a scope, but even if I did, the problem only seems to happen at or
near WOT on climbout and in flight. I can run the engine wide open on the
ground and cannot get the backfiring that I get in the air. There must be
enough of a difference in engine loading to cause the problem, so I tend
to think it's not ignition, because if it were, I would be getting the
same problem on the ground.
Brian Trubee
-----Original
Message----- From: Mark Steitle < msteitle@gmail.com> To:
Rotary motors in aircraft < flyrotary@lancaironline.net> Sent:
Sat, May 14, 2011 11:21 am Subject: [FlyRotary] Re: Engine
Tuning
Brian,
A number of us in the rotary group have had ignition issues with the
EC-2. I fought it for over a year, not sure if it was ignition,
tuning, or a little of both. It was running pretty good, then I had
the brilliant idea to switch the 20B's CAS over to a Renesis style
CAS (mounted on the crank pulley). Apparently, the 20B's eccentric
shaft has too much movement to produce a good clean signal. Finally,
in desperation, I switched back to the original CAS and the high rpm
tuning problem was magically cured. Not sure what type CAS you're
using, but you may want to put a scope on the lead to see what is going on
at high rpm.
Mark
On Sat, May 14, 2011 at 10:04 AM, <bktrub@aol.com> wrote:
I've had the same thought- that up at higher rpms I might be having
some sort of ignition problem. Adjusting the mixture does seem to
mitigate it somewhat, so that leads me to think that it is not an
igntion problem. Also, it only seems to happen in flight, not on the
ground, where the loads are a little different. So, I still have
questions about this, but I'm going to approach this from the mixture
angle. If I am having an igntion problem, it's only happening at almost
full throttle and in flight, so I'm scratching my head trying to see how
to test for this.
Brian Trubee
-----Original
Message----- From: Steven W. Boese < SBoese@uwyo.edu> To: Rotary
motors in aircraft < flyrotary@lancaironline.net> Sent:
Fri, May 13, 2011 10:28 pm Subject: [FlyRotary] Re: Engine
Tuning
Brian (and anyone else
with more experience than me),
With my engine stand,
primary injectors as small as 21 lb and secondary injectors from 30 to
50 lb have been used, with MAP up to 30 inches. Mixtures from lean
misfire to rich misfire have been set with RPM up to 5800.
Although misfires can be induced with mixture, at no time was there
anything that could be considered a backfire and certainly nothing like
a grenade. In flight, I have induced misfires with rich as well as
lean mixtures again with nothing like the results you describe. My
plane’s muffler is a hollow tube about 6 inches in diameter 3 feet long
with a slightly less than 2” diameter outlet and two chambers inside
separated by a conical wall. This muffler would seem to be more of
a bomb than a grenade if a backfire were to happen. Doesn’t the
fact that there is a viable fuel-air mixture in the exhaust system seem
to indicate that the problem may be ignition rather than mixture?
This is just a question, not intended to be an answer.
Steve Boese
RV6A 1986 13B NA RD1A
EC2
Since the weather has been
cooperating lately, I've had the opportunity to put a few more hours on
the airplane. On the ground, I can go from an idle up to full throttle
and the engine will be smooth. But when I take off, it seems that as
soon as I'm up a few hundred feet off the runway, I get hellacious
backfiring at full throttle. I can mitigate it a bit by throttling back
to about 5100 rpm, and turning the mixture knob to near full rich. It's
getting to be a bit nerve wracking to take off thinking I've got it
smoothed out and then get a series of hand grenades going off under my
butt. I'm thinking that I'm still running too lean up at map address 106
or so. So, I go into the edit page and richen up the mixture around
those addresses. I think I'm creeping up on smooth full throttle
running.
The
good news is that my coolant runs at 175 degrees and oil at less- so the
cooling is more than effective, I just need to close up my air inlet a
bit or restrict the outflow.
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