Today's Message Index:
----------------------
1. 01:35 PM - fun and games with a manometer (Lynn Matteson)
2. 04:02 PM - Re: fun and games with a manometer (Lloyd & Lorrie Cudnohufsky)
3. 05:52 PM - Re: fun and games with a manometer (Lowell Fitt)
4. 06:16 PM - Re: fun and games with a manometer (Lynn Matteson)
5. 06:51 PM - Re: fun and games with a manometer (Lynn Matteson)
6. 09:34 PM - Re: fun and games with a manometer (Don Hudgeon)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | fun and games with a manometer |
I built a U-tube water manometer this week, and finally got a chance
to try it out (flying) today. Prior to today, I had used it to find a
slight leak in my pitot system, which I fixed by tightening up the
Nylo-Seal fittings while watching the indicated leak disappear. Ever
wonder how much tightening is enough for those fittings? I have, and
now I know....just use a manometer on the system during the assembly
of the fittings, and you'll know when to quit tightening.
Today, I got a chance to fly briefly to test the Jabiru-dictated 2.4"
of water column difference between the inlet air ducts (each side
tested individually), and the exit-air area of the plane. I haven't
had any cooling problems, so I just wanted to test how close my
installation came to meeting that 2.4" measurement. My installation
was pretty close to right on the mark...it read about 2.3" to 2.6"
depending on the bounce of the water in the tube. Pretty happy with
that, I flew home to add a 1" lip to the bottom of my cowl exit. I
bent a 20" length of sheet aluminum to a 60 angle, letting 1" stick
out into the airstream below the cowl, and c-clamped it in place. (I
didn't want to rivet it in place just to test the theory.) I went up
and flew some more...windy day, didn't want to fly too much....and
now I saw about 2.5" to 3" on either of the two air ducts. But the
really interesting thing about the last test, was that I saw a mark
on the aluminum "lip" showing where it was contacting the left
exhaust pipe. Normally, this pipe cleared the cowl/lip by about 1/2",
but apparently during flight, my cowl flexes up enough to allow
contact with the exhaust pipe. No big deal you say, and I agree, but
if that lip is flexing up 1/2", what just happened to the carefully
engineered 3:1 ratio of exit air-to-inlet air that shouldn't change?
Kinda like having a wrong-way operating cowl flap for the exit air,
I'm thinking. So I need to stiffen up the lower cowl exit flange so
that it doesn't flex at all, and then do some more testing....maybe a
center support for the cowl is in order...something that will be
permanently attached to either the cowl or the airframe, but not
both, so as to allow for removing the cowl without having to deal
with another fastener down there.
If anybody's having trouble with overheating issues, yet you're sure
of the "correctness" of your installation, you might think about the
rigidity of things when air pressure gets applied.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Prince prop (64 x 30, P-tip)
Electroair direct-fire ignition system
Rotec TBI-40 injection (sleeved to 36mm)
Status: flying with "Ramcharger" intake manifold...1110 hrs (since
3-27-2006)
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | fun and games with a manometer |
Lynn,
Cool stuff, (no pun intended) how did you get the tubes fastened in the cowl
openings and did you run them into the cockpit? Look forward to hearing more
about the experiments.
Lloyd Cudnohufsky
5 Outback 912 IVO IFA
Northern Mi.
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
Sent: Saturday, May 28, 2011 3:34 PM
Subject: Kitfox-List: fun and games with a manometer
I built a U-tube water manometer this week, and finally got a chance to try
it out (flying) today. Prior to today, I had used it to find a slight leak
in my pitot system, which I fixed by tightening up the Nylo-Seal fittings
while watching the indicated leak disappear. Ever wonder how much tightening
is enough for those fittings? I have, and now I know....just use a manometer
on the system during the assembly of the fittings, and you'll know when to
quit tightening.
Today, I got a chance to fly briefly to test the Jabiru-dictated 2.4"
of water column difference between the inlet air ducts (each side tested
individually), and the exit-air area of the plane. I haven't had any cooling
problems, so I just wanted to test how close my installation came to meeting
that 2.4" measurement. My installation was pretty close to right on the
mark...it read about 2.3" to 2.6"
depending on the bounce of the water in the tube. Pretty happy with that, I
flew home to add a 1" lip to the bottom of my cowl exit. I bent a 20" length
of sheet aluminum to a 60 angle, letting 1" stick out into the airstream
below the cowl, and c-clamped it in place. (I didn't want to rivet it in
place just to test the theory.) I went up and flew some more...windy day,
didn't want to fly too much....and now I saw about 2.5" to 3" on either of
the two air ducts. But the really interesting thing about the last test, was
that I saw a mark on the aluminum "lip" showing where it was contacting the
left exhaust pipe. Normally, this pipe cleared the cowl/lip by about 1/2",
but apparently during flight, my cowl flexes up enough to allow contact with
the exhaust pipe. No big deal you say, and I agree, but if that lip is
flexing up 1/2", what just happened to the carefully engineered 3:1 ratio of
exit air-to-inlet air that shouldn't change?
Kinda like having a wrong-way operating cowl flap for the exit air, I'm
thinking. So I need to stiffen up the lower cowl exit flange so that it
doesn't flex at all, and then do some more testing....maybe a center support
for the cowl is in order...something that will be permanently attached to
either the cowl or the airframe, but not both, so as to allow for removing
the cowl without having to deal with another fastener down there.
If anybody's having trouble with overheating issues, yet you're sure of the
"correctness" of your installation, you might think about the rigidity of
things when air pressure gets applied.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Prince prop (64 x 30, P-tip)
Electroair direct-fire ignition system
Rotec TBI-40 injection (sleeved to 36mm)
Status: flying with "Ramcharger" intake manifold...1110 hrs (since
3-27-2006)
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: fun and games with a manometer |
Sorry Lynn. Don't buy your experimentation. These forums are reserved for
opinions only.
Seriously, I am helping a friend finish a Series V and was interested in the
3:1 ratio. I did a rough measurement on the in vs. out and interestingly
enough, the out only comes close to equaling the inlet area, but not quite.
I am curious if cooling is an issue with these since the radiator and oil
cooler are inside the cowl.
Lowell
--------------------------------------------------
From: "Lynn Matteson" <lynnmatt@jps.net>
Sent: Saturday, May 28, 2011 1:33 PM
Subject: Kitfox-List: fun and games with a manometer
>
> I built a U-tube water manometer this week, and finally got a chance to
> try it out (flying) today. Prior to today, I had used it to find a slight
> leak in my pitot system, which I fixed by tightening up the Nylo-Seal
> fittings while watching the indicated leak disappear. Ever wonder how
> much tightening is enough for those fittings? I have, and now I
> know....just use a manometer on the system during the assembly of the
> fittings, and you'll know when to quit tightening.
>
> Today, I got a chance to fly briefly to test the Jabiru-dictated 2.4" of
> water column difference between the inlet air ducts (each side tested
> individually), and the exit-air area of the plane. I haven't had any
> cooling problems, so I just wanted to test how close my installation came
> to meeting that 2.4" measurement. My installation was pretty close to
> right on the mark...it read about 2.3" to 2.6" depending on the bounce of
> the water in the tube. Pretty happy with that, I flew home to add a 1"
> lip to the bottom of my cowl exit. I bent a 20" length of sheet aluminum
> to a 60 angle, letting 1" stick out into the airstream below the cowl,
> and c-clamped it in place. (I didn't want to rivet it in place just to
> test the theory.) I went up and flew some more...windy day, didn't want
> to fly too much....and now I saw about 2.5" to 3" on either of the two
> air ducts. But the really interesting thing about the last test, was that
> I saw a mark on the aluminum "lip" showing where it was contacting the
> left exhaust pipe. Normally, this pipe cleared the cowl/lip by about
> 1/2", but apparently during flight, my cowl flexes up enough to allow
> contact with the exhaust pipe. No big deal you say, and I agree, but if
> that lip is flexing up 1/2", what just happened to the carefully
> engineered 3:1 ratio of exit air-to-inlet air that shouldn't change?
> Kinda like having a wrong-way operating cowl flap for the exit air, I'm
> thinking. So I need to stiffen up the lower cowl exit flange so that it
> doesn't flex at all, and then do some more testing....maybe a center
> support for the cowl is in order...something that will be permanently
> attached to either the cowl or the airframe, but not both, so as to allow
> for removing the cowl without having to deal with another fastener down
> there.
>
> If anybody's having trouble with overheating issues, yet you're sure of
> the "correctness" of your installation, you might think about the
> rigidity of things when air pressure gets applied.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062
> Prince prop (64 x 30, P-tip)
> Electroair direct-fire ignition system
> Rotec TBI-40 injection (sleeved to 36mm)
> Status: flying with "Ramcharger" intake manifold...1110 hrs (since
> 3-27-2006)
>
>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: fun and games with a manometer |
When you said "radiator" I assumed Rotax, right? I'm not sure if the
3:1 ratio still holds for a water-cooled engine...I have always held
to the 3:1 ratio for air-cooled, starting back in my radio-control
days, and when I got to the Jabiru camp (6 years ago), the first
thing I heard there was 3:1...or 4:1, or 5:1 even! I'm not sure
Jabiru knew back then, just what was required. They seem to do ok in
their own planes, but area little sketchy when it comes to advice for
homebuilts.
Probably better off looking to Rotax for an answer to that one,
Lowell, if that IS what it's powered with.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Prince prop (64 x 30, P-tip)
Electroair direct-fire ignition system
Rotec TBI-40 injection (sleeved to 36mm)
Status: flying with "Ramcharger" intake manifold...1110 hrs (since
3-27-2006)
On May 28, 2011, at 8:50 PM, Lowell Fitt wrote:
> <lcfitt@sbcglobal.net>
>
> Sorry Lynn. Don't buy your experimentation. These forums are
> reserved for opinions only.
>
> Seriously, I am helping a friend finish a Series V and was
> interested in the 3:1 ratio. I did a rough measurement on the in
> vs. out and interestingly enough, the out only comes close to
> equaling the inlet area, but not quite. I am curious if cooling is
> an issue with these since the radiator and oil cooler are inside
> the cowl.
>
> Lowell
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: fun and games with a manometer |
Hi Lloyd-
The Jabiru engine has a pair of cooling ducts made of fiberglas, and
they suggest attaching the tubes (I used 1/4" OD aluminum tubing)
right to the ducts. I drilled into the duct, right between the spark
plugs, and JB Welded them in place, but any location thereabouts
should give you the same pressure, within reason. From these short
tubes, I connected to 1/4" rigid poly-something tubing (hardware
store stuff) with surgical tubing. The surgical tubing was a slightly
loose fit on the poly tubing, but would not pull off. I figured this
might leak a little bit so I rolled back the end of the surgical
tubing back over itself, and that made an almost impossible-to-remove
connection. Anyway, getting back to the run of the tubing, I ran the
poly tubing through an available hole...don't we all have one of
those in our firewall someplace?...and up and over my glare shield. I
stopped them there and made the connection to the manometer, again
with surgical tubing.
Oh, yeah, the manometer I built was similar to the one in:
http://www.iflyez.com/manometer.shtml but I made mine with an
aluminum plate instead of wood (gave me another chance to play with
the TIG), and used smaller tubing than the 3/8" suggested in that
article.
At first I used tap water and detergent and food coloring, and like
they say in the article, "you'll wait HOURS for the bubbles to
settle", so then I used distilled water, a dab of softener to break
the surface tension, and food coloring, and this time the water just
slides up and down the walls of the tubing without hesitation. These
things are so simple to make, but the trick is to print the scale to
*exactly* the dimension given...for accuracy. I converted the knots
numbers to "miles per hour" and checked my airspeed indicator after
first checking for leaks. I found that my airspeed was 2 miles under
at 60 mph, right on at 100 mph, and 1 mile over at 140 mph....close
enough for a Kitfox, in my book. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062
Prince prop (64 x 30, P-tip)
Electroair direct-fire ignition system
Rotec TBI-40 injection (sleeved to 36mm)
Status: flying with "Ramcharger" intake manifold...1110 hrs (since
3-27-2006)
On May 28, 2011, at 6:59 PM, Lloyd & Lorrie Cudnohufsky wrote:
> <7suds@chartermi.net>
>
> Lynn,
> Cool stuff, (no pun intended) how did you get the tubes fastened in
> the cowl
> openings and did you run them into the cockpit? Look forward to
> hearing more
> about the experiments.
>
> Lloyd Cudnohufsky
> 5 Outback 912 IVO IFA
> Northern Mi.
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: fun and games with a manometer |
More Manometer Stuff
Hi Guys
I use a manometer to balance the carbs on my 912. I connect each end of the
U-Shaped clear tubing to each nipple on the intake manifolds where the
balance tube goes. I loop the tubing around a yard stick and put a small
amount of Rislone in the tube. All that is necessary to do is adjust the
throttle linkage so that the Rislone level is EXACTLY the same on each side
of the loop. This instrument is very accurate and very small adjustments
are all that is necessary.
Just to be sure I have recently bought a "Carbmate electronic balancer" as a
check on my adjustments but the manometer is every bit as accurate!! Cost
about $2 compared to $110.
Have fun
Don Hudgeon
Vixen 912UL IVO IFA
On Sat, May 28, 2011 at 6:48 PM, Lynn Matteson <lynnmatt@jps.net> wrote:
>
> Hi Lloyd-
>
> The Jabiru engine has a pair of cooling ducts made of fiberglas, and they
> suggest attaching the tubes (I used 1/4" OD aluminum tubing) right to the
> ducts. I drilled into the duct, right between the spark plugs, and JB Welded
> them in place, but any location thereabouts should give you the same
> pressure, within reason. From these short tubes, I connected to 1/4" rigid
> poly-something tubing (hardware store stuff) with surgical tubing. The
> surgical tubing was a slightly loose fit on the poly tubing, but would not
> pull off. I figured this might leak a little bit so I rolled back the end of
> the surgical tubing back over itself, and that made an almost
> impossible-to-remove connection. Anyway, getting back to the run of the
> tubing, I ran the poly tubing through an available hole...don't we all have
> one of those in our firewall someplace?...and up and over my glare shield. I
> stopped them there and made the connection to the manometer, again with
> surgical tubing.
>
> Oh, yeah, the manometer I built was similar to the one in:
> http://www.iflyez.com/manometer.shtml but I made mine with an
> aluminum plate instead of wood (gave me another chance to play with the
> TIG), and used smaller tubing than the 3/8" suggested in that article.
>
> At first I used tap water and detergent and food coloring, and like they
> say in the article, "you'll wait HOURS for the bubbles to settle", so then I
> used distilled water, a dab of softener to break the surface tension, and
> food coloring, and this time the water just slides up and down the walls of
> the tubing without hesitation. These things are so simple to make, but the
> trick is to print the scale to *exactly* the dimension given...for accuracy.
> I converted the knots numbers to "miles per hour" and checked my airspeed
> indicator after first checking for leaks. I found that my airspeed was 2
> miles under at 60 mph, right on at 100 mph, and 1 mile over at 140
> mph....close enough for a Kitfox, in my book. : )
>
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062
> Prince prop (64 x 30, P-tip)
> Electroair direct-fire ignition system
> Rotec TBI-40 injection (sleeved to 36mm)
> Status: flying with "Ramcharger" intake manifold...1110 hrs (since
> 3-27-2006)
>
>
> On May 28, 2011, at 6:59 PM, Lloyd & Lorrie Cudnohufsky wrote:
>
>> 7suds@chartermi.net>
>>
>> Lynn,
>> Cool stuff, (no pun intended) how did you get the tubes fastened in the
>> cowl
>> openings and did you run them into the cockpit? Look forward to hearing
>> more
>> about the experiments.
>>
>> Lloyd Cudnohufsky
>> 5 Outback 912 IVO IFA
>> Northern Mi.
>>
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|