| leaning makes it worse because it slows down the burn. At the perfectly balanced mixture and two working plugs, each flame front has to make it halfway across the cylinder. With one working plug the flame front has to make it all the way across the cylinder. With a very rich or lean mixture the flame front moves more slowly. So you combined twice as far to go with a mixture that results in a slower burn. On Oct 21, 2013, at 7:36 AM, John Barrett wrote: Time to fess up. The failure mode turned out to be a failed electronic ignition system. I run one Plasma III lightspeed and one mag. The lightspeed quit and I didn't recognize it. It had to have happened during climb out or at level off. The run up prior to take off was entirely normal.
The hot TIT's and EGT's were the result of incomplete fuel burn by the mag that was the only ignition still running. Fuel in the exhaust stacks burns in the turbines and heats everything up real fast. I don't understand why leaning made it worse though. Can anyone explain that?
Lest anyone jump on Klaus, let me be quick to admit it was not a failure of his system but rather an installation defect. As a matter of fact he got on the phone with me on a weekend day and helped trouble shoot it. He overnighted a loaner to me when I didn't have enough tools or access to do adequate system checks and did not laugh at me too badly when the loaner did not fix the problem. A check of the ground for the power circuit showed about 2 Kohms resistance. The fix was to wire in another ground.
Best regards, John Barrett |
Hello John, I am sorry that I missed out on the LOBO fly in discussion of your event.
I have been watching the thread for the answer but I must have missed it if the question was answered. Please let me know what you learned. I have a question about the new dimension of the rub rail material past its retaining bracket on the main gear doors. I put the quire out to LML but did not receive any responses. Thanks, Greg Milnar 651 738 3117
From: John Barrett [mailto:2thman1@gmail.com]
Sent: Tuesday, October 15, 2013 3:11 PM
To: John Barrett
Subject: Hot TITs on X country leg. LIVP We returned home yesterday from East Coast visits following LOBO mtg in Greenville, SC. On the way to Greenville after an intermediate stop in NE, we experienced an engine problem that I brought to the attention of anyone at LOBO who would listen and give advice including Neil George from TCM with Allen Barrett hooked into the discussion by text and cell phone. The short story is that when I reached my planned VFR altitude of 15,500 and levelled off I pulled back power but forgot to lean or reset prop for about ten minutes. Then when I remembered and tried to lean the engine, TITs skyrocketed followed by hot EGT readings. See the attached link to the Savvyanalysisgraphing of the engine behavior and see if you can come up with what went wrong. When you review the graph, you’ll likely notice that I tried twice more after the initial leaning to see if I could get lean of peak and the engine emphatically let me know it did NOT like what I was doing. I can tell you the problem has been resolved and we flew the airplane around the country for another week with no repeats. Now I'm interested to know what LMLers might think caused this because I was totally surprised when I learned what the real problem was. Some of you who were supportive at LOBO already know the answer so let’s see what others come up with. I have many people to thank for amazing help in finding and correcting the problem so I want to go on record as one of the most appreciative people there could be for LOBO, our many vendors and for pilots around the airport in Greenville who gave advice, time, materials, loaned tools and so on. |
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