Today's Message Index:
----------------------
1. 03:23 AM - Re: Here's an idea that DIDN'T work (Tex Mantell)
2. 03:56 AM - Re: Here's an idea that DIDN'T work (Lynn Matteson)
3. 03:56 AM - Re: Here's an idea that DIDN'T work (Lynn Matteson)
4. 04:06 AM - Re: Here's an idea that DIDN'T work (Richard Girard)
5. 04:08 AM - Re: Here's an idea that DIDN'T work (Lynn Matteson)
6. 05:40 AM - Re: Here's an idea that DIDN'T work (Lynn Matteson)
7. 05:50 AM - Re: Here's an idea that DIDN'T work (Lynn Matteson)
8. 07:09 AM - Re: Here's an idea that DIDN'T work (zeprep251@aol.com)
9. 08:49 AM - Re: Here's an idea that DIDN'T work (dons701)
10. 09:10 AM - Re: Here's an idea that DIDN'T work (Lynn Matteson)
11. 09:42 AM - Re: Re: Here's an idea that DIDN'T work (Lynn Matteson)
12. 11:57 AM - Re: Re: Here's an idea that DIDN'T work (jim)
13. 02:54 PM - Re: Here's an idea that DIDN'T work (Peter Harris)
14. 02:54 PM - Re: Here's an idea that DIDN'T work (Peter Harris)
15. 03:02 PM - Re: Re: Here's an idea that DIDN'T work (Peter Harris)
16. 03:03 PM - Re: Re: Here's an idea that DIDN'T work (Peter Harris)
17. 05:55 PM - Re: Here's an idea that DIDN'T work (zeprep251@aol.com)
Message 1
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| Subject: | Re: Here's an idea that DIDN'T work |
Lyn, your idea is like what was tried many years ago. JC Whitney used to
sell them for cars and motor cycles. They had them installed at the air
cleaner and spun the air prior to the carb. Also you have them too large a
surface area. Cut them down a little and I think you will get better result.
Tex
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| Subject: | Re: Here's an idea that DIDN'T work |
Thanks for the tip, Rick. I'll keep that in mind if I decide to
continue with this idea. I think if I tried to use the present piece
and bent it more, the vanes would break off, but making a new one
would let me try that idea. I try to use only the tools I have at
home here, but it may be time to go to a local machine shop for help
on this one. I originally was going to make it out of aluminum, but
it was going to be a major amount of milling, so I tried the
stainless steel and the band saw.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 1:02 AM, Richard Girard wrote:
> Lynn, Just a thought, but any airfoil surface, even a flat plate
> will stall at about a 12 to 16 degrees angle of attack. Before you
> give up, try bending the vanes to something well below this, say 8
> to 10 degrees.
>
> Rick Girard
>
Message 3
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| Subject: | Re: Here's an idea that DIDN'T work |
Hi Peter-
I've been wondering how you've been making out with your injection
experiments. I too have been thinking about making the fuel
distribution unit more centrally located, and came up with the
thought of mounting my TBI below the engine, so that the intake tubes
would all be equal in length ( your potential item #2) and not have
to compete with each other for the incoming charge. Based on what
I've learned while using this TBI and running "lean of peak EGT"
tests, I made the pictured modifications to the intake manifold/
splitter, and it seems to have brought the front cylinders a bit
closer to the rears in terms of EGT and CHT numbers.
Now when operating the engine lean of peak, the EGT's are within
about 60 degrees F, and the CHT's are within a maximum of 20 degrees
F., and as close as 1 degree of each other. I haven't tried to see
how close the EGT's and CHT's would be at higher throttle openings,
but I will.
Because of the title of this thread, I should state that these
pictures are of an idea that DID work.
The first picture shows the area that I would remove from both
halves, and the second picture shows that removal with just the lower
half of the manifold/plenum done. After doing both halves, and test
flying it, it seems to have helped the distribution of air to the
front cylinders. At least it didn't hurt, and that's always nice when
you're potentially ruining an expensive part. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
do not archive
On Sep 7, 2009, at 12:55 AM, Peter Harris wrote:
> Lynn
> I tried a device like that and fitted about 6" upstream from the
> carb. but
> did not see measurable improvement and it limited power so that the
> last
> 11/2" of throttle made no effect.
> After 12 months of trials using a Jenvey throttle body and two
> injectors I
> made a number of different plenums to replace the induction collector
> supplied.
> Because the Jab collector is fed from the end I found that fuel mix
> distribution was not uniform throughout the power range and at
> times uneven
> distribution R to L was causing the engine to vibrate. Also at WOT
> when the
> butterfly is horizontal there is a significant reduction in
> turbulence and a
> tendency for the heavier fuel droplets to accumulate at the far end,
> enriching #1 and #2.
> Using a bowl shaped plenum (as attached here) the effect was so bad
> that the
> engine would shut down over the last inch of throttle with #1 and#2
> miss
> firing rich.
> Based on static RPM I got no extra power from the plenum because
> the engine
> failed rich every time.I spent hours trying to figure out why the
> breakdown.
> I was able to correct this problem by fitting a 11/2" wide plate
> inside my
> plenum placed about 1/2" directly in front of the inlet, like a big
> baffle.
> Then the setup behaved exactly like the Jab collector. #1 and2 were
> rich at
> WOT but the engine did not break down. I got the same max RPM, but
> noticed
> that there was no increase in RPM for the last inch of throttle
> opening.
> I have the same effect with my jab collector.
>> From all of this I deduce that
> 1. The collector as supplied suffers from internal losses which limit
> max power at WOT. and prevent rich failure of #1 and#2
> 2. There is the potential to make a plenum that would solve the
> problem
> provided it has symmetrical outlets and is fed from the centre at the
> bottom.
> 3. There is the potential to get more uniform distribution of the
> charge and with less induction losses there is the potential to get
> more
> power.
> That will be my next project but at present I have a lot of other
> commitments.
> Cheers
> Peter
Message 4
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| Subject: | Re: Here's an idea that DIDN'T work |
Lynn, As it happens I have a small machine shop. If I can help out let me
know. Rather than using stainless, you might consider using brass sheet and
silver soldering the vanes on a hub.
Rick
On Mon, Sep 7, 2009 at 5:55 AM, Lynn Matteson <lynnmatt@jps.net> wrote:
>
> Thanks for the tip, Rick. I'll keep that in mind if I decide to continue
> with this idea. I think if I tried to use the present piece and bent it
> more, the vanes would break off, but making a new one would let me try
> that idea. I try to use only the tools I have at home here, but it may be
> time to go to a local machine shop for help on this one. I originally was
> going to make it out of aluminum, but it was going to be a major amount of
> milling, so I tried the stainless steel and the band saw.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 760.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
>
>
> On Sep 7, 2009, at 1:02 AM, Richard Girard wrote:
>
> Lynn, Just a thought, but any airfoil surface, even a flat plate will
>> stall at about a 12 to 16 degrees angle of attack. Before you give up, try
>> bending the vanes to something well below this, say 8 to 10 degrees.
>>
>> Rick Girard
>>
>>
>
>
Message 5
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| Subject: | Re: Here's an idea that DIDN'T work |
Hi Peter-
What I was trying to copy WAS a product made for the car industry...a
"cyclone-something". Did you try this in your Jabiru engine? When I
searched the websites, I couldn't find one small enough to fit behind
the injector body.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 12:07 AM, peter disher wrote:
> <pjdisher@bigpond.com>
>
> Hi Lynn,
> Late last year I tried the very same thing, a product made here,
> all ready aviable in Australia and distrubted to the car (auto)
> industry. Made of SS, 6 vains and enclosed in a tube the diameter
> of the vains and a 1/2 long. cost me $165.00.
> It did NOT work, just like your results NBG. I did get my money back.
> Pete D
> VH-PDI
>
> ----- Original Message ----- From: "Lynn Matteson" <lynnmatt@jps.net>
> To: <jabiruengine-list@matronics.com>
> Sent: Monday, September 07, 2009 1:21 PM
> Subject: JabiruEngine-List: Here's an idea that DIDN'T work
>
>
>> Last week or so, I mentioned I was going to build a "turbulator" for
>> my induction system. Here are pictures of what I built and what it
>> looks (looked) like installed.
>>
Message 6
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| Subject: | Re: Here's an idea that DIDN'T work |
Thanks for the input. Tex....after I got to looking at it, I realized
that the vanes were too large, but thought that the edge thickness
was not too much of a restriction, but the air moving through it had
different ideas. : ) And yes, this was just a regurgitation of an
old idea.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 6:22 AM, Tex Mantell wrote:
> <wb2ssj@frontiernet.net>
>
> Lyn, your idea is like what was tried many years ago. JC Whitney
> used to sell them for cars and motor cycles. They had them
> installed at the air cleaner and spun the air prior to the carb.
> Also you have them too large a surface area. Cut them down a little
> and I think you will get better result. Tex
>
>
Message 7
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| Subject: | Re: Here's an idea that DIDN'T work |
Now THERE'S a good idea! Sometimes I really overlook the obvious in
my old age. You're absolutely right, a silver soldered assembly would
be the way to go, and I can do this at home. I have a lathe, milling
attachment, band saw, and all the assorted hand tools in my small
shop, and sometimes I try to make a machined job, when all that is
called for is the hand tools and the silver solder. Thanks for the
suggestion and the offer to help, Rick.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 7:02 AM, Richard Girard wrote:
> Lynn, As it happens I have a small machine shop. If I can help out
> let me know. Rather than using stainless, you might consider using
> brass sheet and silver soldering the vanes on a hub.
>
> Rick
>
> On Mon, Sep 7, 2009 at 5:55 AM, Lynn Matteson <lynnmatt@jps.net>
> wrote:
> <lynnmatt@jps.net>
>
> Thanks for the tip, Rick. I'll keep that in mind if I decide to
> continue with this idea. I think if I tried to use the present
> piece and bent it more, the vanes would break off, but making a new
> one would let me try that idea. I try to use only the tools I
> have at home here, but it may be time to go to a local machine shop
> for help on this one. I originally was going to make it out of
> aluminum, but it was going to be a major amount of milling, so I
> tried the stainless steel and the band saw.
>
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 760.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
>
>
> On Sep 7, 2009, at 1:02 AM, Richard Girard wrote:
>
> Lynn, Just a thought, but any airfoil surface, even a flat plate
> will stall at about a 12 to 16 degrees angle of attack. Before you
> give up, try bending the vanes to something well below this, say 8
> to 10 degrees.
>
> Rick Girard
>
>
> ==========
> -List" target="_blank">http://www.matronics.com/Navigator?
> JabiruEngine-List
> ==========
> http://forums.matronics.com
> ==========
> le, List Admin.
> ="_blank">http://www.matronics.com/contribution
> ==========
>
>
> www.matronics.com/contribution _-
> ===========================================================
Message 8
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| Subject: | Re: Here's an idea that DIDN'T work |
Lynn,
?Is there any way to change the shape of the support bolt housing to tear drop?The
round tube has to create a lot of turbulence down stream.
Gary Aman Jabiru 2200A 475 hrs
-----Original Message-----
From: Lynn Matteson <lynnmatt@jps.net>
Sent: Mon, Sep 7, 2009 6:53 am
Subject: Re: JabiruEngine-List: Here's an idea that DIDN'T work
Hi Peter-?
I've been wondering how you've been making out with your injection experiments.
I too have been thinking about making the fuel distribution unit more centrally
located, and came up with the thought of mounting my TBI below the engine,
so that the intake tubes would all be equal in length ( your potential item #2)
and not have to compete with each other for the incoming charge. Based on what
I've learned while using this TBI and running "lean of peak EGT" tests, I made
the pictured modifications to the intake manifold/splitter, and it seems to
have brought the front cylinders a bit closer to the rears in terms of EGT and
CHT numbers.?
?
Now when operating the engine lean of peak, the EGT's are within about 60 degrees
F, and the CHT's are within a maximum of 20 degrees F., and as close as 1 degree
of each other. I haven't tried to see how close the EGT's and CHT's would
be at higher throttle openings, but I will.?
?
Because of the title of this thread, I should state that these pictures are of
an idea that DID work.?
?
The first picture shows the area that I would remove from both halves, and the
second picture shows that removal with just the lower half of the manifold/plenum
done. After doing both halves, and test flying it, it seems to have helped
the distribution of air to the front cylinders. At least it didn't hurt, and
that's always nice when you're potentially ruining an expensive part. : )?
?
Lynn Matteson?
Kitfox IV Speedster, taildragger?
Jabiru 2200, #2062, 760.3 hrs?
Sensenich 62"x46" Wood prop?
Electroair direct-fire ignition system?
Rotec TBI-40 injection?
Status: flying?
do not archive?
?
?
?
On Sep 7, 2009, at 12:55 AM, Peter Harris wrote:?
?
> Lynn?
> I tried a device like that and fitted about 6" upstream from the > carb. but?
> did not see measurable improvement and it limited power so that the > last?
> 11/2" of throttle made no effect.?
> After 12 months of trials using a Jenvey throttle body and two > injectors I?
> made a number of different plenums to replace the induction collector?
> supplied.?
> Because the Jab collector is fed from the end I found that fuel mix?
> distribution was not uniform throughout the power range and at > times uneven?
> distribution R to L was causing the engine to vibrate. Also at WOT > when the?
> butterfly is horizontal there is a significant reduction in > turbulence and
a?
> tendency for the heavier fuel droplets to accumulate at the far end,?
> enriching #1 and #2.?
> Using a bowl shaped plenum (as attached here) the effect was so bad > that the?
> engine would shut down over the last inch of throttle with #1 and#2 > miss?
> firing rich.?
> Based on static RPM I got no extra power from the plenum because > the engine?
> failed rich every time.I spent hours trying to figure out why the > breakdown.?
> I was able to correct this problem by fitting a 11/2" wide plate > inside my?
> plenum placed about 1/2" directly in front of the inlet, like a big > baffle.?
> Then the setup behaved exactly like the Jab collector. #1 and2 were > rich at?
> WOT but the engine did not break down. I got the same max RPM, but > noticed?
> that there was no increase in RPM for the last inch of throttle > opening.?
> I have the same effect with my jab collector.?
>> From all of this I deduce that?
> 1. The collector as supplied suffers from internal losses which limit?
> max power at WOT. and prevent rich failure of #1 and#2?
> 2. There is the potential to make a plenum that would solve the > problem?
> provided it has symmetrical outlets and is fed from the centre at the?
> bottom.?
> 3. There is the potential to get more uniform distribution of the?
> charge and with less induction losses there is the potential to get > more?
> power.?
> That will be my next project but at present I have a lot of other?
> commitments.?
> Cheers?
> Peter?
?
Message 9
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| Subject: | Re: Here's an idea that DIDN'T work |
Hi Lynn and All
Just a few thoughts, a device that takes the "wet" flow of air and fuel and imparts
a centrifuge effect will tend to throw the heavier droplets to the outside.
I also remember a device that used four counter rotating vortices, created
by bending metal tabs protruding inward from the inside of a large hole in sheet
metal and claimed to solve the separation problem. I thought it was called
Swarrup, or something like that, but when I tried to search the net I found
nothing.
Thank you for the pictures of your manifold. Heavier droplets of fuel retain
their kinetic energy and do not want to turn with the air only to slam to the
front for 1&2. One could wonder what would happen if the center divider was completely
removed, what encouragement would the high velocity fuel and air have
to alternately flow to the rear cylinders (3&4).
If the fuel and air were heated to the point of vaporization before entering
the manifold you could have the even distribution needed to run leaner because
the current system is rich to compromise the factory design. Don
--------
Zenith 701 #76120
Jabiru #2456 51 hours
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=261870#261870
Message 10
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| Subject: | Re: Here's an idea that DIDN'T work |
Do you mean the thing that sits between the upper and the lower
halves of the manifold? I refer to this part as the splitter, and
when I spoke with Pete about its shape, he said that Jabiru had done
some testing and found the present shape to be the best. Here is a
picture of that part and as you can see, it is already teardrop
shaped when viewed from above. I had a notion to carve it into an
hour-glass shape, (as seen viewed straight on, as in the picture I
sent previously) and I still might, the next time I have the manifold
off the engine. The only problem with that idea is that there is an
(unused) threaded hole back at the narrow part of the teardrop, that
would be exposed if I carved it to an hour glass shape. I thought of
simply screwing an aluminum bolt into this hole, then proceeding with
the shaping of it, but decided not to...guess I chickened out. That
rear hole could also be filled with some structural adhesive/epoxy/
whatever, and then it would just be carved away as the shape took
place. The front hole...the only one that gets used in the actual
assembly...has enough meat around it, that it would allow some
carving away on either side of it. Just to make sure we're on the
same page here, this shot shows that splitter from above, and I would
cut away on each side of the splitter such that the plan view of the
splitter remains the same shape, but when viewed vertically, the
sides are narrowed...like a good-lookin' babe in great shape when
viewed from the front (minus a few of the "accessories" of course).
And of course when I say the "rear hole" it is actually toward the
front of the engine in a tractor environment, but it is in the rear
of the airflow.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 10:07 AM, zeprep251@aol.com wrote:
> Lynn,
> Is there any way to change the shape of the support bolt housing
> to tear drop?The round tube has to create a lot of turbulence down
> stream.
> Gary Aman Jabiru 2200A 475 hrs
Message 11
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| Subject: | Re: Here's an idea that DIDN'T work |
Thanks for your thoughts, Don. It might just be that the better
atomization of the Rotec TBI is what is making my EGT's and CHT's
more even than with the Bing. Smaller droplets, therefore less
inertia. I seem to recall that Pete said that the factory tried
several different shapes of that divider/splitter and could find
nothing better than the present teardrop shape. He said they tried a
more blunt shape as well. I can't believe they didn't try leaving it
out, and they very well could have, but I don't recall whether Pete
said that or not.
Speaking of "heated to the point of vaporization before entering the
manifold", I have found that if I pull on the carb heat, my rpm's go
up about 60-80, the fuel flow goes up about point-2 to point-3
gallons per hour, and the plane turns slightly to the left, due to
the increase in rpm/torque. This is during straight and level flight
running about 2750 rpm's and using about 3.0 gph, during "lean of
peak EGT" operation. When I push the carb heat off, the plane returns
to the original flight direction, and the rpm's drop, as well as the
fuel usage. Talk about sensitive! Now this turn to the left is not
dramatic, just noticeable.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 11:48 AM, dons701 wrote:
> <burdon1@comcast.net>
>
> Hi Lynn and All
> Just a few thoughts, a device that takes the "wet" flow of air
> and fuel and imparts a centrifuge effect will tend to throw the
> heavier droplets to the outside. I also remember a device that used
> four counter rotating vortices, created by bending metal tabs
> protruding inward from the inside of a large hole in sheet metal
> and claimed to solve the separation problem. I thought it was
> called Swarrup, or something like that, but when I tried to search
> the net I found nothing.
> Thank you for the pictures of your manifold. Heavier droplets of
> fuel retain their kinetic energy and do not want to turn with the
> air only to slam to the front for 1&2. One could wonder what would
> happen if the center divider was completely removed, what
> encouragement would the high velocity fuel and air have to
> alternately flow to the rear cylinders (3&4).
> If the fuel and air were heated to the point of vaporization
> before entering the manifold you could have the even distribution
> needed to run leaner because the current system is rich to
> compromise the factory design. Don
>
> --------
> Zenith 701 #76120
> Jabiru #2456 51 hours
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=261870#261870
>
>
Message 12
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| Subject: | Re: Here's an idea that DIDN'T work |
Hi Lynn
Something you may want to try is to replace the "splitter wing" with a round
bar stock 12mm in dia. I have had some customers try this with good results.
The theory behind the round stock it it cause's turbulence in the plenum for
better fuel distribution? But the guys that have done this report the EGT's
are more uniform between the cyl's..
Jim McCormick
Jabiru Pacific LLC
255 W Fallbrook Suite 202B
Fresno, Ca 93711
P 559.431.1701
F 559.233.3676
www.jabirupacific.com
On 9/7/09 9:35 AM, "Lynn Matteson" <lynnmatt@jps.net> wrote:
>
> Thanks for your thoughts, Don. It might just be that the better
> atomization of the Rotec TBI is what is making my EGT's and CHT's
> more even than with the Bing. Smaller droplets, therefore less
> inertia. I seem to recall that Pete said that the factory tried
> several different shapes of that divider/splitter and could find
> nothing better than the present teardrop shape. He said they tried a
> more blunt shape as well. I can't believe they didn't try leaving it
> out, and they very well could have, but I don't recall whether Pete
> said that or not.
>
> Speaking of "heated to the point of vaporization before entering the
> manifold", I have found that if I pull on the carb heat, my rpm's go
> up about 60-80, the fuel flow goes up about point-2 to point-3
> gallons per hour, and the plane turns slightly to the left, due to
> the increase in rpm/torque. This is during straight and level flight
> running about 2750 rpm's and using about 3.0 gph, during "lean of
> peak EGT" operation. When I push the carb heat off, the plane returns
> to the original flight direction, and the rpm's drop, as well as the
> fuel usage. Talk about sensitive! Now this turn to the left is not
> dramatic, just noticeable.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 760.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
>
>
>
>
>
>
> On Sep 7, 2009, at 11:48 AM, dons701 wrote:
>
>> <burdon1@comcast.net>
>>
>> Hi Lynn and All
>> Just a few thoughts, a device that takes the "wet" flow of air
>> and fuel and imparts a centrifuge effect will tend to throw the
>> heavier droplets to the outside. I also remember a device that used
>> four counter rotating vortices, created by bending metal tabs
>> protruding inward from the inside of a large hole in sheet metal
>> and claimed to solve the separation problem. I thought it was
>> called Swarrup, or something like that, but when I tried to search
>> the net I found nothing.
>> Thank you for the pictures of your manifold. Heavier droplets of
>> fuel retain their kinetic energy and do not want to turn with the
>> air only to slam to the front for 1&2. One could wonder what would
>> happen if the center divider was completely removed, what
>> encouragement would the high velocity fuel and air have to
>> alternately flow to the rear cylinders (3&4).
>> If the fuel and air were heated to the point of vaporization
>> before entering the manifold you could have the even distribution
>> needed to run leaner because the current system is rich to
>> compromise the factory design. Don
>>
>> --------
>> Zenith 701 #76120
>> Jabiru #2456 51 hours
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=261870#261870
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
>
Message 13
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| Subject: | Here's an idea that DIDN'T work |
Looks like good work Lynn. Maybe you have got the splitter as good as it can
be.
I am interested in your test to WOT especially to see if you find no
increase in power for the last inch of throttle. I have taken this effect to
be an indication of losses in the collector (as proven by my test with the
baffle plate inserted) but it may be that my prop is overloading the system.
I am getting 2760RPM static with all of my ground tests.
The prop is 55X72 as used on my Quickie and I get 170KTS CAS at 2900RPM WOT
in level flight at 3000ft.It would be nice to find that extra power and
maybe set a record for this type.
Peter
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Monday, 7 September 2009 8:54 PM
Subject: Re: JabiruEngine-List: Here's an idea that DIDN'T work
Hi Peter-
I've been wondering how you've been making out with your injection
experiments. I too have been thinking about making the fuel
distribution unit more centrally located, and came up with the
thought of mounting my TBI below the engine, so that the intake tubes
would all be equal in length ( your potential item #2) and not have
to compete with each other for the incoming charge. Based on what
I've learned while using this TBI and running "lean of peak EGT"
tests, I made the pictured modifications to the intake manifold/
splitter, and it seems to have brought the front cylinders a bit
closer to the rears in terms of EGT and CHT numbers.
Now when operating the engine lean of peak, the EGT's are within
about 60 degrees F, and the CHT's are within a maximum of 20 degrees
F., and as close as 1 degree of each other. I haven't tried to see
how close the EGT's and CHT's would be at higher throttle openings,
but I will.
Checked by AVG - www.avg.com
17:51:00
Message 14
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| Subject: | Here's an idea that DIDN'T work |
Hi Lynn,
Yes it was a product called "Hiclone" overpriced at AUD160 and very heavily
promoted as a boost to power and economy.It has a double row of vanes in SS.
The idea is probably OK but I think any benefit is offset by the choking
effect as the device limits airflow.
I think it would work better if the diameter was much larger, then perhaps
tapered to the TB entry. This would accelerate the swirling air with limited
obstruction to the flow.
BTW I found it useful to conduct some tests using a high pressure spray of
water from a spray gun.
Peter
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Monday, 7 September 2009 9:05 PM
Subject: Re: JabiruEngine-List: Here's an idea that DIDN'T work
Hi Peter-
What I was trying to copy WAS a product made for the car industry...a
"cyclone-something". Did you try this in your Jabiru engine? When I
searched the websites, I couldn't find one small enough to fit behind
the injector body.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 760.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Sep 7, 2009, at 12:07 AM, peter disher wrote:
> <pjdisher@bigpond.com>
>
> Hi Lynn,
> Late last year I tried the very same thing, a product made here,
> all ready aviable in Australia and distrubted to the car (auto)
> industry. Made of SS, 6 vains and enclosed in a tube the diameter
> of the vains and a 1/2 long. cost me $165.00.
> It did NOT work, just like your results NBG. I did get my money back.
> Pete D
> VH-PDI
>
> ----- Original Message ----- From: "Lynn Matteson" <lynnmatt@jps.net>
> To: <jabiruengine-list@matronics.com>
> Sent: Monday, September 07, 2009 1:21 PM
> Subject: JabiruEngine-List: Here's an idea that DIDN'T work
>
>
>> Last week or so, I mentioned I was going to build a "turbulator" for
>> my induction system. Here are pictures of what I built and what it
>> looks (looked) like installed.
>>
Checked by AVG - www.avg.com
17:51:00
Message 15
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| Subject: | Re: Here's an idea that DIDN'T work |
Don,
The induction collector is bolted flat to the sump.
When I discussed this with the Jabiru design engineer he admitted it was a
compromise. Heating the charge reduces efficiency but improves the
distribution as you suggest.
Peter
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of dons701
Sent: Tuesday, 8 September 2009 1:49 AM
Subject: JabiruEngine-List: Re: Here's an idea that DIDN'T work
Hi Lynn and All
Just a few thoughts, a device that takes the "wet" flow of air and fuel
and imparts a centrifuge effect will tend to throw the heavier droplets to
the outside. I also remember a device that used four counter rotating
vortices, created by bending metal tabs protruding inward from the inside of
a large hole in sheet metal and claimed to solve the separation problem. I
thought it was called Swarrup, or something like that, but when I tried to
search the net I found nothing.
Thank you for the pictures of your manifold. Heavier droplets of fuel
retain their kinetic energy and do not want to turn with the air only to
slam to the front for 1&2. One could wonder what would happen if the center
divider was completely removed, what encouragement would the high velocity
fuel and air have to alternately flow to the rear cylinders (3&4).
If the fuel and air were heated to the point of vaporization before
entering the manifold you could have the even distribution needed to run
leaner because the current system is rich to compromise the factory design.
Don
--------
Zenith 701 #76120
Jabiru #2456 51 hours
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=261870#261870
Checked by AVG - www.avg.com
17:51:00
Message 16
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| Subject: | Re: Here's an idea that DIDN'T work |
Jim,
Afriend of mine has replaced this part with a half round shape with the flat
at rear and he claims an improvement in distribution.
But I intend to continue with experiments for a bottom fed symmetrical
plenum.
Peter
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of jim
Sent: Tuesday, 8 September 2009 4:55 AM
Subject: Re: JabiruEngine-List: Re: Here's an idea that DIDN'T work
Hi Lynn
Something you may want to try is to replace the "splitter wing" with a round
bar stock 12mm in dia. I have had some customers try this with good results.
The theory behind the round stock it it cause's turbulence in the plenum for
better fuel distribution? But the guys that have done this report the EGT's
are more uniform between the cyl's..
Jim McCormick
Jabiru Pacific LLC
255 W Fallbrook Suite 202B
Fresno, Ca 93711
P 559.431.1701
F 559.233.3676
www.jabirupacific.com
On 9/7/09 9:35 AM, "Lynn Matteson" <lynnmatt@jps.net> wrote:
>
> Thanks for your thoughts, Don. It might just be that the better
> atomization of the Rotec TBI is what is making my EGT's and CHT's
> more even than with the Bing. Smaller droplets, therefore less
> inertia. I seem to recall that Pete said that the factory tried
> several different shapes of that divider/splitter and could find
> nothing better than the present teardrop shape. He said they tried a
> more blunt shape as well. I can't believe they didn't try leaving it
> out, and they very well could have, but I don't recall whether Pete
> said that or not.
>
> Speaking of "heated to the point of vaporization before entering the
> manifold", I have found that if I pull on the carb heat, my rpm's go
> up about 60-80, the fuel flow goes up about point-2 to point-3
> gallons per hour, and the plane turns slightly to the left, due to
> the increase in rpm/torque. This is during straight and level flight
> running about 2750 rpm's and using about 3.0 gph, during "lean of
> peak EGT" operation. When I push the carb heat off, the plane returns
> to the original flight direction, and the rpm's drop, as well as the
> fuel usage. Talk about sensitive! Now this turn to the left is not
> dramatic, just noticeable.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 760.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
>
>
>
>
>
>
> On Sep 7, 2009, at 11:48 AM, dons701 wrote:
>
>> <burdon1@comcast.net>
>>
>> Hi Lynn and All
>> Just a few thoughts, a device that takes the "wet" flow of air
>> and fuel and imparts a centrifuge effect will tend to throw the
>> heavier droplets to the outside. I also remember a device that used
>> four counter rotating vortices, created by bending metal tabs
>> protruding inward from the inside of a large hole in sheet metal
>> and claimed to solve the separation problem. I thought it was
>> called Swarrup, or something like that, but when I tried to search
>> the net I found nothing.
>> Thank you for the pictures of your manifold. Heavier droplets of
>> fuel retain their kinetic energy and do not want to turn with the
>> air only to slam to the front for 1&2. One could wonder what would
>> happen if the center divider was completely removed, what
>> encouragement would the high velocity fuel and air have to
>> alternately flow to the rear cylinders (3&4).
>> If the fuel and air were heated to the point of vaporization
>> before entering the manifold you could have the even distribution
>> needed to run leaner because the current system is rich to
>> compromise the factory design. Don
>>
>> --------
>> Zenith 701 #76120
>> Jabiru #2456 51 hours
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=261870#261870
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
>
Checked by AVG - www.avg.com
17:51:00
Message 17
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| Subject: | Re: Here's an idea that DIDN'T work |
? Thanks Lynn,
? One good picture answered all the questions.
? G.Aman
-----Original Message-----
From: Lynn Matteson <lynnmatt@jps.net>
Sent: Mon, Sep 7, 2009 12:03 pm
Subject: Re: JabiruEngine-List: Here's an idea that DIDN'T work
Do you mean the thing that sits between the upper and the lower halves of the manifold?
I refer to this part as the splitter, and when I spoke with Pete about
its shape, he said that Jabiru had done some testing and found the present shape
to be the best. Here is a picture of that part and as you can see, it is
already teardrop shaped when viewed from above. I had a notion to carve it into
an hour-glass shape, (as seen viewed straight on, as in the picture I sent previously)
and I still might, the next time I have the manifold off the engine.
The only problem with that idea is that there is an (unused) threaded hole back
at the narrow part of the teardrop, that would be exposed if I carved it to
an hour glass shape. I thought of simply screwing an aluminum bolt into this
hole, then proceeding with the shaping of it, but decided not to...guess I chickened
out. That rear hole could also be filled with some structural adhesive/epoxy/whatever,
and then it would just be carved awa
y as the shape took place. The front hole...the only one that gets used in the
actual assembly...has enough meat around it, that it would allow some carving
away on either side of it. Just to make sure we're on the same page here, this
shot shows that splitter from above, and I would cut away on each side of the
splitter such that the plan view of the splitter remains the same shape, but
when viewed vertically, the sides are narrowed...like a good-lookin' babe in
great shape when viewed from the front (minus a few of the "accessories" of course).?
?
And of course when I say the "rear hole" it is actually toward the front of the
engine in a tractor environment, but it is in the rear of the airflow.?
?
?
Lynn Matteson?
Kitfox IV Speedster, taildragger?
Jabiru 2200, #2062, 760.3 hrs?
Sensenich 62"x46" Wood prop?
Electroair direct-fire ignition system?
Rotec TBI-40 injection?
Status: flying?
?
On Sep 7, 2009, at 10:07 AM, zeprep251@aol.com wrote:?
?
> Lynn,?
> Is there any way to change the shape of the support bolt housing > to tear drop?The
round tube has to create a lot of turbulence down > stream.?
> Gary Aman Jabiru 2200A 475 hrs?
?
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