Today's Message Index:
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1. 08:46 AM - Long running #3 hot cylinder problem (Galin Hernandez)
2. 09:15 AM - #3 Cylinder problem - resent (Galin Hernandez)
3. 05:47 PM - Hot #3 Cylinder - Msg sent again (Galin Hernandez)
4. 06:28 PM - Problems posting messages (Galin Hernandez)
Message 1
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| Subject: | Long running #3 hot cylinder problem |
I have been fighting an *intermittent* hot #3 cylinder on my Lycoming O360
for years and nothing seemed to work. When the problem shows up I have to
run the engine quite rich to bring the #3 CHT to just under 400F but at the
same time the the other cylinders were at least 50 degrees cooler. Worst
still on many flight the CHT's were fine and all 4 cylinders were very
close to each other. I tried changing the CHT probe with no luck and my
baffling was perfect, or so I thought. Pardon the pun, but this was
baffling.
After reading a completely un unrelated thread on VANS AF on inexpensive
borescopes, I bought a Vividia VA-400 Borescope. Out of curiosity a few
days ago I used the borescope and looked into the firewall *with the cowl
on*. I found that, when installed, the top cowl was folding part of the
baffling down and almost completely blocking air to, you guessed it, the #3
cylinder head.
You can clearly see it in the picture:
https://drive.google.com/file/d/0B-q...ew?usp=sharing
<https://drive.google.com/file/d/0B-qYL3LiViE3cWNCa3AyVWhCelk/view?usp=sharing>
With the cowl top off, the baffles are perfectly aligned with no blockage
whatsoever so everything looks good. With the cowl top on, you can't see
the baffling near cylinder #3 since cylinder #1 blocks the view. I could
not have found this problem without a borescope. I immediately fixed it so
it can never happen again.
After completing two separate 2hr flights (back and forth from Ft. Benning,
GA), everything went perfect. The #3 CHT stayed within 5 degrees of the
other 3 CHT's for the entire flight. My "hottest" cylinder is now #2 but
only a few degrees hotter than #3. All 4 cylinders are within 10 degrees of
each other. Not bad for a carbureted engine. Since I have now flown more
than 4hrs with this configuration with very similar results, I am
optimistic that I finally fixed the problem.
So if you are experiencing one cylinder getting much hotter than the others
and no matter what you do nothing seems to fix it, *check your baffles with
the cowl ON*. Make sure that, when installed, your cowl isn't bending a
baffle preventing air from cooling a particular cylinder. In my case, and
probably most others, you can't check the rear cylinder baffling area
without a borescope.
Message 2
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| Subject: | #3 Cylinder problem - resent |
For some reason this e-mail went through all garbled. Let me try again.
I have been fighting an *intermittent* hot #3 cylinder on my Lycoming O360
for years and nothing seemed to work. When the problem shows up I have to
run the engine quite rich to bring the #3 CHT to just under 400F but at the
same time the the other cylinders were at least 50 degrees cooler. Worst
still on many flight the CHT's were fine and all 4 cylinders were very
close to each other. I tried changing the CHT probe with no luck and my
baffling was perfect, or so I thought. Pardon the pun, but this was
baffling.
After reading a completely un unrelated thread on VANS AF on inexpensive
borescopes, I bought a Vividia VA-400 Borescope. Out of curiosity a few
days ago I used the borescope and looked into the firewall *with the cowl
on*. I found that, when installed, the top cowl was folding part of the
baffling down and almost completely blocking air to, you guessed it, the #3
cylinder head.
You can clearly see it in the picture:
https://drive.google.com/file/d/0B-q...ew?usp=sharing
<https://drive.google.com/file/d/0B-qYL3LiViE3cWNCa3AyVWhCelk/view?usp=sharing>
With the cowl top off, the baffles are perfectly aligned with no blockage
whatsoever so everything looks good. With the cowl top on, you can't see
the baffling near cylinder #3 since cylinder #1 blocks the view. I could
not have found this problem without a borescope. I immediately fixed it so
it can never happen again.
After completing two separate 2hr flights (back and forth from Ft. Benning,
GA), everything went perfect. The #3 CHT stayed within 5 degrees of the
other 3 CHT's for the entire flight. My "hottest" cylinder is now #2 but
only a few degrees hotter than #3. All 4 cylinders are within 10 degrees of
each other. Not bad for a carbureted engine. Since I have now flown more
than 4hrs with this configuration with very similar results, I am
optimistic that I finally fixed the problem.
So if you are experiencing one cylinder getting much hotter than the others
and no matter what you do nothing seems to fix it, *check your baffles with
the cowl ON*. Make sure that, when installed, your cowl isn't bending a
baffle preventing air from cooling a particular cylinder. In my case, and
probably most others, you can't check the rear cylinder baffling area
without a borescope.
Message 3
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| Subject: | Hot #3 Cylinder - Msg sent again |
Hope this message goes through this time.
I have been fighting an *intermittent* hot #3 cylinder on my Lycoming O360
for years and nothing seemed to work. When the problem shows up I have to
run the engine quite rich to bring the #3 CHT to just under 400F but at the
same time the the other cylinders were at least 50 degrees cooler. Worst
still, on many flight the CHT's were fine and all 4 cylinders were very
close to each other. I tried changing the CHT probe with no luck and my
baffling was perfect, or so I thought. Pardon the pun, but it was baffling.
After reading a completely un unrelated thread on VANs Air Force
Forum about inexpensive borescopes, I bought a Vividia VA-400 Borescope.
Last week, and out of curiosity, I used the borescope and looked into the
firewall *with the cowl still on*. I found that, when installed, the top
cowl was folding part of the baffling down and almost completely blocking
air to, you guessed it, the #3 cylinder head.
You can clearly see it in the picture:
https://drive.google.com/file/d/0B-qYL3LiViE3cWNCa3AyVWhCelk/view?usp=sharing
With the cowl top off, the baffles align perfectly with no blockage
whatsoever so everything looks good. With the cowl top on, you can't see
the baffling near cylinder #3 since cylinder #1 blocks the view. I could
not have found this problem without a borescope.
Over the past few days I did two 2hr flights (St Augustine to Ft. Benning
and back) and everything went perfect. The #3 CHT stayed within 5 degrees
of the other 3 CHT's for the entire flight. My "hottest" cylinder was #2
but only a few degrees hotter than #3. All 4 cylinders are within 10
degrees of each other. Not bad for a carbureted engine. Since I have flown
more than 4hrs with very similar results, I am optimistic that I finally
fixed the problem.
So if you are experiencing one cylinder getting much hotter than the others
and no matter what you do nothing seems to fix it, *check your baffles with
the cowl ON*. Make sure that, when installed, your cowl isn't bending a
baffle preventing air from cooling a particular cylinder. In my case, and
probably most others, you can't check the rear cylinder baffling area
without a borescope.
Message 4
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| Subject: | Problems posting messages |
I have tried to post 3 messages with no luck. Is anybody else having this
problem?
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