 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
BobbyPaulk(at)comcast.net
Guest
|
 Posted: Sat Jul 27, 2013 5:02 am Post subject: CO |
 |
|
p { margin: 0; }Guys,
I had posted some time back about CO in the cockpit of my 601XL ( Jabiru ). I had circled a friends hangar 3 times at another airport at 80 MPH. ( high angle of attack ) When I straightened up to fly home I was nauseous and smelled exhaust fumes very strongly. The CO monitor pill was solid black. I opened both cabin air vents even though it was about 40 deg. outside. I had a very bad headache for the next 4 ~ 5 Hrs.
I extended my exhaust pipe another 5 or 6 inches with a 45 deg. turn down and it seemed to help. I thought I had sealed the firewall completely but one day when I had a light in the engine compartment and the hangar was dark I looked in the cockpit & found two small leaks in the firewall right behind the lower engine mounts. This was on the quick build kit.
While my engine was running very rich I noticed the black stains on the belly just behind the firewall were running forward back toward the low pressure area at the firewall. I have tried adding a skirt to the lower cowl with no improvement.
I also saw the black stains around the belly access panel. Summer seems to be O.K. due to the air vents being open and pressurizing the cockpit somewhat, winter when the vents are closed is when I experience the worst smells. The cockpit on the XL has a strong negative pressure - you can check this by getting your shirt sleeve or shop rag close to the canopy rail where it is not sealed.
The exhaust extension, re-sealing the firewall, and the engine finally running correctly have all helped but I still get a whiff of CO particularly at a high angle of attack or slow speed.
I am still trying to find a way to seal the 6 built in leaks in the Jabiru exhaust connections.
Any ideas?? Wraps usually burn away in 4 or 5 hours.
Bobby ( age 75 )
Zodiac 601 XL "B"
Jabiru 3300 S/N 1141
Sensenich 64" x 51" Prop
Bing Carb 260 Main & 285 Needle Jet
Status - Flying 185 hrs.
Do Not Archive
[quote][b]
| | - The Matronics Zenith601-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?Zenith601-List |
|
|
|
| Back to top |
|
 |
BobbyPaulk(at)comcast.net
Guest
|
| Posted: Sun Jul 28, 2013 1:43 pm Post subject: CO |
|
|
I should have said the cockpit has positive pressure instead of neg.
It has less positive pressure with the outside air vents closed.
[quote][b]
| | - The Matronics Zenith601-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?Zenith601-List |
|
|
|
| Back to top |
|
|
Tim Juhl
Joined: 21 Mar 2006
Posts: 488
Location: "Thumb" of Michigan
|
| Posted: Tue Aug 13, 2013 9:57 am Post subject: Re: CO |
|
|
Not to be picky, but CO has no odor. You might still be getting CO in the cockpit without associated exhaust odor.
Every installation is going to be a little different. The vast majority of CO will be going out the stacks so I'd be looking for fuselage openings in areas of low pressure downwind from them. I wouldn't think the small leaks around the joints of the exhaust system would account for much and in any case, most of that goes out the bottom of the cowl.
Obvious things like holes in the firewall, leaks around steering rod boots or shutters, poor seal between the wrap around cowl and the firewall are all possibilities for some leakage. Others have reported CO coming in thru openings in the aft fuselage.
Wish I could be more helpful.
Tim
| | - The Matronics Zenith601-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?Zenith601-List |
|
_________________
______________
CFII
Champ L16A flying
Zodiac XL - Jabiru 3300A
Almost done! It'll fly in spring! |
|
| Back to top |
|
|
psm(at)att.net
Guest
|
| Posted: Tue Aug 13, 2013 10:18 am Post subject: CO |
|
|
I have heard many people suggest the most likely entry point for carbon
monoxide in any plane is the tail cone. Indeed we lost one of our
pilots to what is suspected to be CO poisoning last year. He had a
wheels up landing in his Bonanza and was ferrying it back for repairs
when he suddenly lost control and crashed a half mile from the
destination. The wheels up landing knocked off the tail cone.
On my Zodiac I have two "Eye-ball" vents for outside air mounted on the
instrument panel. I can feel air blowing out the rear area between the
canopy and side of the fuselage in normal flight. I firmly believe this
reduces the chances of getting CO into the cabin because of the positive
pressure.
Paul
Camas, WA
Zodiac XL in phase II
On 8/13/2013 10:57 AM, Tim Juhl wrote:
| Quote: |
Not to be picky, but CO has no odor. You might still be getting CO in the cockpit without associated exhaust odor.
Every installation is going to be a little different. The vast majority of CO will be going out the stacks so I'd be looking for fuselage openings in areas of low pressure downwind from them. I wouldn't think the small leaks around the joints of the exhaust system would account for much and in any case, most of that goes out the bottom of the cowl.
Obvious things like holes in the firewall, leaks around steering rod boots or shutters, poor seal between the wrap around cowl and the firewall are all possibilities for some leakage. Others have reported CO coming in thru openings in the aft fuselage.
Wish I could be more helpful.
Tim
--------
______________
CFII
Champ L16A flying
Zodiac XL - Jabiru 3300A
Wing modifications done - back working on the fuselage
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=406637#406637
|
| | - The Matronics Zenith601-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?Zenith601-List |
|
|
|
| Back to top |
|
|
Tim Juhl
Joined: 21 Mar 2006
Posts: 488
Location: "Thumb" of Michigan
|
| Posted: Tue Aug 13, 2013 10:31 am Post subject: Re: CO |
|
|
Paul,
Since it is impractical to try to seal off all the openings in the tail cone, have you given any thought to a practical way to pressurize that area? Maybe a NACA scoop on the side or the like? I know of fellows who have put holes in the bulkhead behind the baggage shelf but I'm not sure if that would make things better or worse.
Tim
| | - The Matronics Zenith601-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?Zenith601-List |
|
_________________
______________
CFII
Champ L16A flying
Zodiac XL - Jabiru 3300A
Almost done! It'll fly in spring! |
|
| Back to top |
|
|
psm(at)att.net
Guest
|
| Posted: Tue Aug 13, 2013 10:47 am Post subject: CO |
|
|
Hi Tim,
I don't think you need to do anything to pressurize the tail cone so
long as you have air pressure entering the cabin as I described. The
FWF kit from Pete has ports on the cowl for this purpose. You just need
to come up with a vent structure for the cabin. I used the 2 inch
eyeball type vents ( from Spruce?), and they work just fine. I just
don't feel comfortable ever closing them all the way. When it is cool
out I prefer to redirect them so the don't blow on me or my passenger
(on the rare occasion I have a passenger).
About the other Jab questions all I can say is for my money Pete is the
man. I would follow his advice.
Paul
On 8/13/2013 11:31 AM, Tim Juhl wrote:
| Quote: |
Paul,
Since it is impractical to try to seal off all the openings in the tail cone, have you given any thought to a practical way to pressurize that area? Maybe a NACA scoop on the side or the like? I know of fellows who have put holes in the bulkhead behind the baggage shelf but I'm not sure if that would make things better or worse.
Tim
--------
______________
CFII
Champ L16A flying
Zodiac XL - Jabiru 3300A
Wing modifications done - back working on the fuselage
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=406643#406643
|
| | - The Matronics Zenith601-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?Zenith601-List |
|
|
|
| Back to top |
|
|
Ron Lendon
Joined: 10 Jan 2006
Posts: 685
Location: Clinton Twp., MI
|
| Posted: Tue Aug 13, 2013 5:24 pm Post subject: Re: CO |
|
|
I don't have a CO problem but last winter it was getting difficult to stay warm. That's when I noticed a positive air flow from the rear fuselage. To combat that I sealed the canopy with Great Stuff foam along the IP and sticky backed weatherstrip foam along the canopy rails and flashing at the rear of the XL canopy.
That helped but what really got the air flowing out the rear was using that same sticky backed weatherstrip around the inspection access panel on the bottom of the fuselage. Also used aluminum tape over the hinge on that panel.
During the winter the 2" eyeball vents are totally blocked off and that keeps it toasty in even subzero fahrenheit temps.
| | - The Matronics Zenith601-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?Zenith601-List |
|
_________________
Ron Lendon
WW Corvair with Roy's Garage 5th bearing
CH 601 XLB
N601LT - Flying
http://www.mykitlog.com/rlendon
Corvair Engine Prints:
https://sites.google.com/site/corvairenginedata/ |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
