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brian(at)lloyd.com
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 Posted: Thu Jun 16, 2011 2:56 pm Post subject: Detonation |
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On Thu, Jun 16, 2011 at 8:52 AM, Roger Kemp M.D. <viperdoc(at)mindspring.com (viperdoc(at)mindspring.com)> wrote:
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Bryan,
I glad you can say that but unless someone F&^%#$ the airplane after I personally gapped them, put them in and torqued them that was not the case. They were not dropped. Especially two brand danged new sets after each occurrence.
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If someone had FOD'ed your intake you would see where things were banging around inside the cylinder. (Have you looked inside the cylinder?) As I said, detonation would show as wiping all the deposits clean from inside the engine, not changed plug gaps. So if the insides of your cylinders look normal and your plug gaps have changed, someone or something has changed them. It ain't detonation.
Also neither the M14P nor the Huosai have high enough compression to trigger detonation under any set of conditions even remotely resembling normal when running 100LL. The detonation margin is pretty big in that case.
| Quote: |
That would lead me back to the initial thoughts when I found the plug gaps flattened on #1, #3, and #4. The second time around it was on #6. Maybe I just need to call the FBI and let them investigate this as tampering with an aircraft? What do ya think?
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I think that is way more likely than detonation.
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There plenty of drama going on around 08A these days with certain politicians wanting to close the airport and I have been dead center in the middle of the fight. Not because I wanted to be though.
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Ah, the life of a lightning rod. 
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian(at)lloyd.com (brian(at)lloyd.com)
+1.767.617.1365 (Dominica)
+1.931.492.6776 (USA)
(+1.931.4.WB6RQN)
[quote][b]
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viperdoc(at)mindspring.co
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| Posted: Thu Jun 16, 2011 5:28 pm Post subject: Detonation |
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The inside of the cylinders looked like ground glass or 20 grit sand paper. There was some pitting on what had been brand new chrome top pistons. When I pull the plugs again sometime next week I'll try to get pix off the bore scope. Did not buy the one that would do photos.
Need to read my earlier post on this saga.
What you don't see in the plug picture is what the element looks like on the Surface under 10 power magnification. It looks like it got hit with with #8 bird shot. Mottled or copper kettle appearance would be another description I don't think man's hands with a screw driver but or a wrench would make that appearance. Not unless they beat the element down with a meat tenderizer mallet could it look that way.
Come to think of it, the inside of the #1 cylinder sleeve looked that way too. Instead of the expected smooth silver appearance it was speckled on the inside.
Doc
Sent from my iPad
On Jun 16, 2011, at 5:52 PM, Brian Lloyd <brian(at)lloyd.com (brian(at)lloyd.com)> wrote:
[quote]On Thu, Jun 16, 2011 at 8:52 AM, Roger Kemp M.D. <[url=mailto:viperdoc(at)mindspring.com]viperdoc(at)mindspring.com (viperdoc(at)mindspring.com)[/url]> wrote:
| Quote: |
Bryan,
I glad you can say that but unless someone F&^%#$ the airplane after I personally gapped them, put them in and torqued them that was not the case. They were not dropped. Especially two brand danged new sets after each occurrence.
|
If someone had FOD'ed your intake you would see where things were banging around inside the cylinder. (Have you looked inside the cylinder?) As I said, detonation would show as wiping all the deposits clean from inside the engine, not changed plug gaps. So if the insides of your cylinders look normal and your plug gaps have changed, someone or something has changed them. It ain't detonation.
Also neither the M14P nor the Huosai have high enough compression to trigger detonation under any set of conditions even remotely resembling normal when running 100LL. The detonation margin is pretty big in that case.
| Quote: |
That would lead me back to the initial thoughts when I found the plug gaps flattened on #1, #3, and #4. The second time around it was on #6. Maybe I just need to call the FBI and let them investigate this as tampering with an aircraft? What do ya think?
|
I think that is way more likely than detonation.
| Quote: |
There plenty of drama going on around 08A these days with certain politicians wanting to close the airport and I have been dead center in the middle of the fight. Not because I wanted to be though.
|
Ah, the life of a lightning rod.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
[url=mailto:brian(at)lloyd.com]brian(at)lloyd.com (brian(at)lloyd.com)[/url]
+1.767.617.1365 (Dominica)
+1.931.492.6776 (USA)
(+1.931.4.WB6RQN)
[b]
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brian(at)lloyd.com
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| Posted: Thu Jun 16, 2011 6:52 pm Post subject: Detonation |
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On Thu, Jun 16, 2011 at 6:25 PM, Roger Kemp M.D. <viperdoc(at)mindspring.com (viperdoc(at)mindspring.com)> wrote:
| Quote: | The inside of the cylinders looked like ground glass or 20 grit sand paper. There was some pitting on what had been brand new chrome top pistons. When I pull the plugs again sometime next week I'll try to get pix off the bore scope. Did not buy the one that would do photos.
Need to read my earlier post on this saga.
What you don't see in the plug picture is what the element looks like on the Surface under 10 power magnification. It looks like it got hit with with #8 bird shot. Mottled or copper kettle appearance would be another description I don't think man's hands with a screw driver but or a wrench would make that appearance. Not unless they beat the element down with a meat tenderizer mallet could it look that way.
Come to think of it, the inside of the #1 cylinder sleeve looked that way too. Instead of the expected smooth silver appearance it was speckled on the inside.
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Sounds like FOD that came through the induction system. Time to tear down the engine.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian(at)lloyd.com (brian(at)lloyd.com)
+1.767.617.1365 (Dominica)
+1.931.492.6776 (USA)
(+1.931.4.WB6RQN)
[quote][b]
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cjpilot710(at)aol.com
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| Posted: Fri Jun 17, 2011 6:35 am Post subject: Detonation |
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Do you have a oil filter on this engine? Here is the reason I ask.
A number of years ago when I had a HS6 260hp engine on my CJ, the Chinese exhaust stack burnt off near one end. In doing so, it melted the "rabbit ears" of the alternate air into the carb. Being at an airshow Dough over night-ed one to me, so I could fly home. There as I was repairing the rabbit ears, I noticed gobs of solidified melted aluminum on the intake screen at the carb throat. That's when I realized that molten aluminum had been ingested into the engine. (It ran just fine by the way) I than opened the oil filter (10 micron) and found it filled with silvery aluminum sand. We than did a compression check which turned out normal (mid 70s). I drained all the oil, put on a new filter, and test ran the engine. I opened up the filter and found some aluminum sand again but nothing like the first time. Again I drained the oil and new filter and again test ran the engine. This time NO aluminum at all. All this time oil pressures and temps were normal. Lucky? I guess so. I flew another 100 hours on that engine before going to the M14P.
These engine are very tough. One cylinder on my M14 came from the factory, with the wrong ring in place of the oil ring. It ran 438 hours! before the piston lands failed. I think Brain might be correct, you may have gotten some FOD from someplace during the cylinder change. From what you describe, it may be steel material of some kind. Question - were you able to account for ALL the piston rings or their parts, during disassembly? Also, have you checked the check valves on the cylinder for the start air line?
If you did get some kind of FOD though the induction system you might bore scope the super charger. You should be able to check for possible blade damage by removing on of the intake tubes.
Good luck.
Jim "Pappy" Goolsby
In a message dated 6/16/2011 10:53:03 P.M. Eastern Daylight Time, brian(at)lloyd.com writes:
| Quote: |
On Thu, Jun 16, 2011 at 6:25 PM, Roger Kemp M.D. <viperdoc(at)mindspring.com (viperdoc(at)mindspring.com)> wrote:
| Quote: | The inside of the cylinders looked like ground glass or 20 grit sand paper. There was some pitting on what had been brand new chrome top pistons. When I pull the plugs again sometime next week I'll try to get pix off the bore scope. Did not buy the one that would do photos.
Need to read my earlier post on this saga.
What you don't see in the plug picture is what the element looks like on the Surface under 10 power magnification. It looks like it got hit with with #8 bird shot. Mottled or copper kettle appearance would be another description I don't think man's hands with a screw driver but or a wrench would make that appearance. Not unless they beat the element down with a meat tenderizer mallet could it look that way.
Come to think of it, the inside of the #1 cylinder sleeve looked that way too. Instead of the expected smooth silver appearance it was speckled on the inside.
|
Sounds like FOD that came through the induction system. Time to tear down the engine.
--
Brian Lloyd, WB6RQN/J79BPL
3191 Western Dr.
Cameron Park, CA 95682
brian(at)lloyd.com (brian(at)lloyd.com)
+1.767.617.1365 (Dominica)
+1.931.492.6776 (USA)
(+1.931.4.WB6RQN)
|
[quote][b]
| | - The Matronics Yak-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Yak-List |
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