Author: MRMcDavid@... Time: Thu Aug 30, 2001 9:15 am PDT Link
Hey guys --- I've been following this cowl door discussion and I
have a question.... Seems like if the door "relaxes" and opens when
taxiing then the path of least resistance for cooling airflow would
be through the door, thus robbing the cylinders of much of the
cooling mass they need to stay healthy. During rollout and a long
taxi back to the hangar I wonder if high CHT might become an issue.
Is this a valid concern?
Monte (N63KM res)
> > When you are taxing or stopped , it automatically opens to let
the heat out :>) If it seems OK, I'm thinking of putting two doors
on my next project.
Author: "Paul Stratman" <pauls@...> Time: Thu Aug 30, 2001 9:59 am PDT Link
All cooling air is contained by the baffle system.
The oil door is behind the baffles.
Paul
Author: "Jerry Calvert" <rv6bldr@...> Time: Thu Aug 30, 2001 3:10 pm PDT Link
The air pressure that is keeping the door shut is air that has already gone through the baffles and cylinders and is pressurizing the rest of the cowl before it exits out the bottom of the cowl. So, there will be no cooling loss...it may even help by allowing more heated air to escape and be replaced by cooler inlet air while taxing.
Jerry Calvert
Edmond Ok
-6
----- Original Message -----
From: MRMcDavid@f... (mailto:mrmcdavid@f...)
To: vansairforce@yahoogroups.com (mailto:vansairforce@yahoogroups.com)
Sent: Thursday, August 30, 2001 11:10 AM
Subject: [VAF Mailing List] Re:Cowl Door; Additional considerations
Hey guys --- I've been following this cowldoor discussion and I
have a question.... Seems like if the door "relaxes" and opens when
taxiing then the path of least resistance for cooling airflow would
be through the door, thus robbing the cylindersof much of the
cooling mass they need to stay healthy. During rollout and a long
taxi back to the hangar I wonder if high CHT might become an issue.
Is this a valid concern?
Monte (N63KM res)
> > When you are taxing or stopped , it automatically opens to let
the heat out :>) If it seems OK, I'm thinking of putting two doors
on my next project.
--------------------------------------------------------------
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Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service (http://docs.yahoo.com/info/terms/).
(end of quote)
Author: MRMcDavid@... Time: Fri Aug 31, 2001 7:26 am PDT Link
Jerry, Paul... Good point!!
Clearly I didn't have the brain fully engaged on this question.
Thanks for the clarification. So the original post (on this topic)
noting that the door swings shut in flght is evidence of a fair
amount of pressure behind the baffling (and ahead of the cowling
exit). Do I have that right? I'm presuming that the overall
cowling "flow control" is really regulated by the size of the exit
area.
Monte
--- In vansairforce@y..., "Jerry Calvert" <rv6bldr@h...> wrote:
> The air pressure that is keeping the door shut is air that has
already gone through the baffles and cylinders and is pressurizing the
rest of the cowl before it exits out the bottom of the cowl. So,
there will be no cooling loss...it may even help by allowing more
heated air to escape and be replaced by cooler inlet air while taxing.
>
> Jerry Calvert
> Edmond Ok
> -6
> ----- Original Message -----
> From: MRMcDavid@f...
> To: vansairforce@y...
> Sent: Thursday, August 30, 2001 11:10 AM
> Subject: [VAF Mailing List] Re:Cowl Door; Additional
considerations
> Hey guys --- I've been following this cowl door discussion and I
> have a question.... Seems like if the door "relaxes" and opens
when
> taxiing then the path of least resistance for cooling airflow
would
> be through the door, thus robbing the cylinders of much of the
> cooling mass they need to stay healthy. During rollout and a long
> taxi back to the hangar I wonder if high CHT might become an
issue.
> Is this a valid concern?
> Monte (N63KM res)
>
> > > When you are taxing or stopped , it automatically opens to let
> the heat out :>) If it seems OK, I'm thinking of putting two
doors
> on my next project.
> Yahoo! Groups Sponsor
> ADVERTISEMENT
>
> Start here...
>
> Height:
> 345678 ft 01234567891011in
>
> Weight:
> lbs. kg.
> --------------------------------------------------------------
> Van's Air Force - World Wide Wing (http://www.vansaircraft.net)
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
Author: "Doug Reeves" <vansairforce@...> Time: Fri Aug 31, 2001 9:03 am PDT Link
Hey guys,
Roger wrote a really nice article on this very topic in my 'Builder's
Modifications' section. It's at www.vansaircraft.net under 'Builder
Mods' or you can jump direct to it at:
http://www.metronet.com/~dreeves/buildermodifications/oilaccessdoormod
.htm
Best,
Doug
--- In vansairforce@y..., MRMcDavid@f... wrote:
> Jerry, Paul... Good point!!
>
> Clearly I didn't have the brain fully engaged on this question.
> Thanks for the clarification. So the original post (on this topic)
> noting that the door swings shut in flght is evidence of a fair
> amount of pressure behind the baffling (and ahead of the cowling
> exit). Do I have that right? I'm presuming that the overall
> cowling "flow control" is really regulated by the size of the exit
> area.
> Monte
> --- In vansairforce@y..., "Jerry Calvert" <rv6bldr@h...> wrote:
> > The air pressure that is keeping the door shut is air that has
> already gone through the baffles and cylinders and is pressurizing
the
> rest of the cowl before it exits out the bottom of the cowl. So,
> there will be no cooling loss...it may even help by allowing more
> heated air to escape and be replaced by cooler inlet air while
taxing.
> >
> > Jerry Calvert
> > Edmond Ok
> > -6
> > ----- Original Message -----
> > From: MRMcDavid@f...
> > To: vansairforce@y...
> > Sent: Thursday, August 30, 2001 11:10 AM
> > Subject: [VAF Mailing List] Re:Cowl Door; Additional
> considerations
> > Hey guys --- I've been following this cowl door discussion
and I
> > have a question.... Seems like if the door "relaxes" and
opens
> when
> > taxiing then the path of least resistance for cooling airflow
> would
> > be through the door, thus robbing the cylinders of much of the
> > cooling mass they need to stay healthy. During rollout and a
long
> > taxi back to the hangar I wonder if high CHT might become an
> issue.
> > Is this a valid concern?
> > Monte (N63KM res)
> >
> > > > When you are taxing or stopped , it automatically opens to
let
> > the heat out :>) If it seems OK, I'm thinking of putting two
> doors
> > on my next project.
> > Yahoo! Groups Sponsor
> > ADVERTISEMENT
> >
> > Start here...
> >
> > Height:
> > 345678 ft 01234567891011in
> >
> > Weight:
> > lbs. kg.
> > --------------------------------------------------------------
> > Van's Air Force - World Wide Wing (http://www.vansaircraft.net)
> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> Service.
Author: "Bernie Kerr" <kerrjb@...> Time: Fri Aug 31, 2001 10:09 am PDT Link
Yep, you have it right. You get more cooling while moving at low speeds or
stopped on the ground, yet it automatically goes to normal doors closed in
flight. I still have not tested it at low angles of attack, ie vne speed in
a shallow dive or low airspeed but a high rate of descent to see it is
banging open and closed. There was a comment about birds etc getting in it
when open and parked, but heck I leave it that way most of the time anyway.
Maybe the old screw there to close if you feel need to ain't all bad.
Bernie Kerr
----- Original Message -----
From: <MRMcDavid@f...>
To: <vansairforce@yahoogroups.com>
Sent: Friday, August 31, 2001 10:24 AM
Subject: [VAF Mailing List] Re:Cowl Door; Additional considerations
> Jerry, Paul... Good point!!
>
> Clearly I didn't have the brain fully engaged on this question.
> Thanks for the clarification. So the original post (on this topic)
> noting that the door swings shut in flght is evidence of a fair
> amount of pressure behind the baffling (and ahead of the cowling
> exit). Do I have that right? I'm presuming that the overall
> cowling "flow control" is really regulated by the size of the exit
> area.
> Monte
> --- In vansairforce@y..., "Jerry Calvert" <rv6bldr@h...> wrote:
> > The air pressure that is keeping the door shut is air that has
> already gone through the baffles and cylinders and is pressurizing the
> rest of the cowl before it exits out the bottom of the cowl. So,
> there will be no cooling loss...it may even help by allowing more
> heated air to escape and be replaced by cooler inlet air while taxing.
> >
> > Jerry Calvert
> > Edmond Ok
> > -6
> > ----- Original Message -----
> > From: MRMcDavid@f...
> > To: vansairforce@y...
> > Sent: Thursday, August 30, 2001 11:10 AM
> > Subject: [VAF Mailing List] Re:Cowl Door; Additional
> considerations
> > Hey guys --- I've been following this cowl door discussion and I
> > have a question.... Seems like if the door "relaxes" and opens
> when
> > taxiing then the path of least resistance for cooling airflow
> would
> > be through the door, thus robbing the cylinders of much of the
> > cooling mass they need to stay healthy. During rollout and a long
> > taxi back to the hangar I wonder if high CHT might become an
> issue.
> > Is this a valid concern?
> > Monte (N63KM res)
> >
> > > > When you are taxing or stopped , it automatically opens to let
> > the heat out :>) If it seems OK, I'm thinking of putting two
> doors
> > on my next project.
> > Yahoo! Groups Sponsor
> > ADVERTISEMENT
> >
> > Start here...
> >
> > Height:
> > 345678 ft 01234567891011in
> >
> > Weight:
> > lbs. kg.
> > --------------------------------------------------------------
> > Van's Air Force - World Wide Wing (http://www.vansaircraft.net)
> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> Service.
> --------------------------------------------------------------
> Van's Air Force - World Wide Wing (http://www.vansaircraft.net)
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/