|
|
|
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.
=
=
|
|