Modified Exhaust Pipe ala Bingelis

One of the methods I want to try to reduce the noise of my Tailwind is
to modify my exhaust pipe as described on page 101 in Bingelis' book
"Firewall Forward." I have a couple of questions.
1) First, has anyone done this and how successful was it?
2) On pages 101 and 106 Bingelis says to bend the rod "back for louver
effect." But in the example on page 107 it looks like the rod was bent
forward to make the louver. Tony describes it as an "excellent job."
Bending back would seem to allow the exhaust gas to escape out the
holes and bending forward would seem to allow the relative wind to flow
into the holes. In either case the flow of the exhaust gas out the
pipe would be disrupted, which, I think is the intent. Any suggestions
on which way to go and if one way would work better than another?

Thanks,
Tom

If this is the type of louvering you're trying to do:

http://www.spiretech.com/~guynoir/Pup/exhaust1.jpg

I did it by making a paper layout using cad, wrapping it around the
pipe, then drilling holes into the pipe. I only perforated the outboard
half of the pipe. Then I deburred the holes, stuck a rod or a drill bit
in each hole and pulled it aft as far as it would go. It turned out
really well. The exhaust was substantially louder, though, but I wasn't
following Bingelis's instructions when I made it. In fact, I don't know
what Bingelis's instructions are.

If you really want a quiet exhaust, here's a link to an article by Tony
Bingelis on the "Swiss Style Muffler":

http://www.piteraq.dk/flight/muffler.html

gtm wrote:
One of the methods I want to try to reduce the noise of my Tailwind is
to modify my exhaust pipe as described on page 101 in Bingelis' book
"Firewall Forward." I have a couple of questions.
1) First, has anyone done this and how successful was it?
2) On pages 101 and 106 Bingelis says to bend the rod "back for louver
effect." But in the example on page 107 it looks like the rod was bent
forward to make the louver. Tony describes it as an "excellent job."
Bending back would seem to allow the exhaust gas to escape out the
holes and bending forward would seem to allow the relative wind to flow
into the holes. In either case the flow of the exhaust gas out the
pipe would be disrupted, which, I think is the intent. Any suggestions
on which way to go and if one way would work better than another?

Thanks,
Tom



--
J Kimmel

www.metalinnovations.com

"Cuius testiculos habes, habeas cardia et cerebellum." - When you have
their full attention in your grip, their hearts and minds will follow.

John,

Thanks for the two links. The article concerning the Swiss Muffler was
the most complete one I've seen. Thanks!

Tom

John Kimmel wrote:
If this is the type of louvering you're trying to do:

http://www.spiretech.com/~guynoir/Pup/exhaust1.jpg

I did it by making a paper layout using cad, wrapping it around the
pipe, then drilling holes into the pipe. I only perforated the outboard
half of the pipe. Then I deburred the holes, stuck a rod or a drill bit
in each hole and pulled it aft as far as it would go. It turned out
really well. The exhaust was substantially louder, though, but I wasn't
following Bingelis's instructions when I made it. In fact, I don't know
what Bingelis's instructions are.

If you really want a quiet exhaust, here's a link to an article by Tony
Bingelis on the "Swiss Style Muffler":

http://www.piteraq.dk/flight/muffler.html

gtm wrote:
One of the methods I want to try to reduce the noise of my Tailwind is
to modify my exhaust pipe as described on page 101 in Bingelis' book
"Firewall Forward." I have a couple of questions.
1) First, has anyone done this and how successful was it?
2) On pages 101 and 106 Bingelis says to bend the rod "back for louver
effect." But in the example on page 107 it looks like the rod was bent
forward to make the louver. Tony describes it as an "excellent job."
Bending back would seem to allow the exhaust gas to escape out the
holes and bending forward would seem to allow the relative wind to flow
into the holes. In either case the flow of the exhaust gas out the
pipe would be disrupted, which, I think is the intent. Any suggestions
on which way to go and if one way would work better than another?

Thanks,
Tom



--
J Kimmel

www.metalinnovations.com

"Cuius testiculos habes, habeas cardia et cerebellum." - When you have
their full attention in your grip, their hearts and minds will follow.

gtm wrote:

John,

Thanks for the two links. The article concerning the Swiss Muffler was
the most complete one I've seen. Thanks!

Tom


Essentially they homebuilt their own "Glass Pack" muffler avaliable at most
auto parts stores.
John

"UltraJohn" wrote

Essentially they homebuilt their own "Glass Pack" muffler avaliable at
most
auto parts stores.

But at a fraction of the weight!. Those things are heavy!

I also believe the Auto store's glass packs are built with a steel tube,
instead of stainless mesh for the inner tube. They are not nearly as
effective, because of that reason.
--
Jim in NC

John Kimmel wrote:
...

If you really want a quiet exhaust, here's a link to an article by Tony
Bingelis on the "Swiss Style Muffler":

http://www.piteraq.dk/flight/muffler.html


Is it just me, or does anyone else find it peculiar that he
discusses how it may be difficult to find 80 mm Aluminum tube
(which I sould think most homebuilders could approximate for
themselves using sheet and rivets, with 3" nominal PCV pipe
for a mandrel) but says nothing at all about where to get
glass cloth, though he IS careful to point out that _fiberglass_
cloth won't work.

So, where do you get glass cloth?

--

FF

On 10 Aug 2005 13:42:49 -0700, wrote:


John Kimmel wrote:
...

If you really want a quiet exhaust, here's a link to an article by Tony
Bingelis on the "Swiss Style Muffler":

http://www.piteraq.dk/flight/muffler.html


Is it just me, or does anyone else find it peculiar that he
discusses how it may be difficult to find 80 mm Aluminum tube
(which I sould think most homebuilders could approximate for
themselves using sheet and rivets, with 3" nominal PCV pipe
for a mandrel) but says nothing at all about where to get
glass cloth, though he IS careful to point out that _fiberglass_
cloth won't work.

So, where do you get glass cloth?

He didn't say don't use fiberglas cloth, he said fibergas mat which is
not woven. fibergas cloth is glass cloth. use as loose a weave as you
can find. Check the Aircraft Spruce catalog.

Ed Sullivan wrote:

...

He didn't say don't use fiberglas cloth, he said [don't use]
fibergas mat which is
not woven. fibergas cloth is glass cloth. use as loose a weave as you
can find. Check the Aircraft Spruce catalog.

Aha! So it was just me. Thanks.

--

FF

wrote in message
oups.com...

John Kimmel wrote:
...

If you really want a quiet exhaust, here's a link to an article by Tony
Bingelis on the "Swiss Style Muffler":

http://www.piteraq.dk/flight/muffler.html


Is it just me, or does anyone else find it peculiar that he
discusses how it may be difficult to find 80 mm Aluminum tube
(which I sould think most homebuilders could approximate for
themselves using sheet and rivets, with 3" nominal PCV pipe
for a mandrel) but says nothing at all about where to get
glass cloth, though he IS careful to point out that _fiberglass_
cloth won't work.

So, where do you get glass cloth?

--

FF
For the 80 mm Aluminum tubing, you might contact the local hang glider
dealership. Maybe there's a broken cross bar you can beg or buy. Crossbars
would usually be 7075, if that makes a difference.

Tim Ward