X-Virus-Scanned: clean according to Sophos on Logan.com
Return-Path: <wdleonard@gmail.com>
Received: from yw-out-2324.google.com ([74.125.46.29] verified)
by logan.com (CommuniGate Pro SMTP 5.2.3)
with ESMTP id 2959225 for flyrotary@lancaironline.net; Sun, 08 Jun 2008 23:35:09 -0400
Received-SPF: pass
receiver=logan.com; client-ip=74.125.46.29; envelope-from=wdleonard@gmail.com
Received: by yw-out-2324.google.com with SMTP id 3so1219071ywj.7
for <flyrotary@lancaironline.net>; Sun, 08 Jun 2008 20:34:30 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=gamma;
h=domainkey-signature:received:received:message-id:date:from:to
:subject:in-reply-to:mime-version:content-type:references;
bh=FuMFisuT90bFE1rerAb2+4S7prTm0jRSEwzgdXD8ZxU=;
b=bxQcmNU8NbKycxw4WHK/RQ2X2lcPzB01nI0q0peSAyeBMiypD7sPqFXMEG+KrOC7xK
K0TcHblJjFc0/cER8RKf90BLt+frzX9hfjeVGmmVdRYTHlx6q+SQs5vSROd+ur9WMN07
5bRlEjeddIkAimLqQqtEuo9RRIPF28WduyjY8=
DomainKey-Signature: a=rsa-sha1; c=nofws;
d=gmail.com; s=gamma;
h=message-id:date:from:to:subject:in-reply-to:mime-version
:content-type:references;
b=bG8Tl5cymHMT6Mvr+DY/Jm8rPZp8BLPf0k+gO+kyvOsvjA153wUjL5qDC+Ox2tSlYl
x7HTQp0RWb1/Me06EtmlAcOHpR0Ui2BSujbERgbcSHvrlNSpsrB2KWWuX8UY0Q+2RKDA
RR5VawnSjATufacS9jy+IFwnORBkLc2HcOIhw=
Received: by 10.150.156.20 with SMTP id d20mr5478864ybe.33.1212982470829;
Sun, 08 Jun 2008 20:34:30 -0700 (PDT)
Received: by 10.150.145.16 with HTTP; Sun, 8 Jun 2008 20:34:30 -0700 (PDT)
Message-ID: <1c23473f0806082034j3d90d380j9b763e9f6c37db29@mail.gmail.com>
Date: Sun, 8 Jun 2008 20:34:30 -0700
From: "David Leonard" <wdleonard@gmail.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Exhaust and Muffler designs.
In-Reply-To: <list-2958883@logan.com>
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_Part_17199_10570541.1212982470830"
References: <list-2958883@logan.com>
------=_Part_17199_10570541.1212982470830
Content-Type: text/plain; charset=WINDOWS-1252
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
As always Al, probably the best flying example I have seen!
--=20
David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
On Sun, Jun 8, 2008 at 1:14 PM, Al Gietzen <ALVentures@cox.net> wrote:
> Exhaust and muffler design in the rotary installation is one of the more
> complex of all the installation issues. There are, and have been so many
> variations among the various installations that there is little statistic=
al
> proof of anything. I'll add a few comments and opinions that may be
> relevant, and describe what I did. It may trigger some ideas for you to
> think about. My system on the 20B is now approaching 100 hours =96 not a =
long
> term proof =96 but it is still solid.
>
>
>
> The exhaust temps out of the port are very high, typically in the
> neighborhood of 1600F, and sometimes maybe 1700F. Couple this with press=
ure
> pulses and vibrational loads, and corrosive environment, and you have a v=
ery
> demanding situation. When you look at material properties to handle this=
,
> things narrow down pretty rapidly, particularly if you also want light
> weight as we do in aviation. Stainless steels, like 321, can handle the
> temps and be a workable exhaust =96 but, design for low stress levels the=
n
> becomes a must, because SS are subject to 'stress corrosion' at these
> temps. Combine the high temperatures and vibrational stress and you get
> inter-granular corrosion which weakens the material and it eventually fal=
ls
> apart.
>
>
>
> On way to alleviate that is to use inconel. It gives you higher
> temperature capability and corrosion resistance. And it gives you higher
> cost. But is it worth it to reduce your risk a forced landing in an
> unfriendly place? Compared to the total cost of your airplane it's a sma=
ll
> amount. Maybe cut cost somewhere where it is less critical to safety.
>
>
>
> Another thing to consider is that the more quickly you can expand the
> exhaust gas, the more quickly you can deal with lower temperatures. Char=
les
> Law =96 temp (degree K) goes down in direct proportion to increased volum=
e.
> This becomes more complex in an exhaust system because of other factors, =
but
> it still works in your favor. The gas will expand down a constant diamet=
er
> pipe, but expanding into a BIG pipe can make a significant drop.
>
>
>
> That can be one of the advantages of the tangential muffler/manifold, or
> the design that Neil presented. The amount of the temp drop of course
> depends on the pressure in that bigger can. These designs have their own
> possible failure modes associated with welded joints and thermal stresses=
,
> but at least there is nothing there that is going to plug up the flow
> downstream. The skill of the welder and the post-weld heat treatment are
> important factors.
>
>
>
> These units are generally bolted directly to the engine via the short
> header pipes, so vibration loads are a factor. Ideally you'd like to have
> stress (and thermal expansion) de-coupling between the engine and the
> muffler/manifold, but since the engine can move relative to it's mount yo=
u
> either have to accommodate significant movement, or support it to the eng=
ine
> by some other means then the header pipes.
>
>
>
> And then there is the matter of the exit pipe(s) and secondary mufflers.
> Those have to be supported as well =96 an unsupported length of pipe exte=
nding
> from the muffler is an ideal candidate for some vibrational resonance whi=
ch
> will fail the system somewhere. And the further away from the engine
> centerline, the greater the loads.
>
>
>
> My exhaust system is shown in the first attached photo. This is in a push=
er
> configuration. It is an inconel tangential manifold/muffler supported to
> the engine by short inconel header pipes which are welded to a heavy RB
> steel flange. It has a convex 'head' at the front, and a conical outlet t=
o
> the exit pipe. It has internal vanes welded at an angle on the inside
> surface opposite the exit from the headers (you can see the welds on the
> outside) to help break up the pulses and direct the exhaust toward the ex=
it.
> They also prevent possible "swirl-flow choking" which could increase back
> pressure. There are 'straightening' vanes in the conical exit section.
>
>
>
> The exit pipe is clamped (custom heavy SS clamp) to the inlet pipe of the
> secondary muffler (I'll call it a resonator). The resonator is also of m=
y
> design and is made of 321 SS. It is basically a straight through 2 =BE" =
pipe
> that is drilled full of =BC" holes (about 100), contained within outer 5"=
dia.
> pipe. The inner pipe has an orifice plate at the center which has a 1 5/=
8"
> opening. This orifice produces some restriction to the flow through the
> resonator to force some of it outward through the holes, and back through
> the holes to exit. The purpose of the resonator is to knock down the
> pressure peaks a bit more. Measurements on the dyno showed that resonato=
r
> knocked another 8 db off the sound level and had no noticeable effect on =
the
> HP.
>
>
>
> The plug in the resonator closes a port originally intended for the O2
> sensor. But it didn't work well in that location because the temperature =
was
> too low (interesting, huh). I had to move it to the inlet pipe.
>
>
>
> Last but not least, there is a SS support at the end which clamps solidly
> to the redrive. The clamp is designed to be rigid laterally, but to also =
be
> an effective heat choke. This supports the resonator, and reduces the
> likelihood of any resonance vibration in the system.
>
>
>
> I originally thought that the resonator internals may not last more than =
50
> hours, but at 95 hours they are still solid. Which brings up another poin=
t.
> It is easily inspected. I can see those internals from the exit end, and =
I
> can stick a screwdriver or ratchet handle or whatever; in there and bang
> around to be sure things are sound. I inspect all the welds in the exhau=
st
> system every time I remove the cowl, or at least every 10 hours or so. M=
ake
> your system inspectable, and keep an eye on it.
>
>
>
> I wouldn't call it "quiet", but I've had people say they like the way it
> sounds. Time will tell its reliability.
>
>
>
> Best,
>
>
>
> Al Gietzen
>
>
>
>
>
> If you go through the archives, you'll find lots of examples =
of
>
> failed muffler designs. Many by your's truly. I think I've tried every
>
> concoction known to man and the Swiss. They all worked... for a while.
>
> My best overall design (see attached) is a 2" tube, full of
> holes
>
> inside a 5" tube. All made of 16ga SS, all welded together. Needless to
>
> say, the flange is more like 3/16" - 1/4" SS. The inside end of the 2"
> tube
>
> is welded to the end cap of the 5" tube. That blocks off the one end of
> the
>
> 2" tube and secures it from movement. The exhaust end of the 2" tube is
>
> welded through a 2" hole in the other 5" end cap. Rather than drilling t=
he
>
> 2" tube full of round holes, we cut slots with a saw. Then take a big fl=
at
>
> blade screwdriver, stick it in the slot and bend it over. This creates a=
n
>
> oblong hole. (Much easier than drilling into SS. This is what will go o=
n
>
> the Volmer.
>
>
>
> The sound is quite acceptable, it fits inside the cowl and Ji=
m
> M.'s
>
> version lasted the life of the aircraft... 600+ hours.
>
>
>
> Neil
>
>
>
> PS: Are you considering Rough River?
>
>
>
>
>
>
>
> -----Original Message-----
>
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
>
> Behalf Of Al Wick
>
> Sent: Saturday, June 07, 2008 4:57 PM
>
> To: Rotary motors in aircraft
>
> Subject: [FlyRotary] Re: Mistral Crash Analysis
>
>
>
> C'mon guys. You do this every time there's a crash. Instantly go into
>
> rationalization mode. It's unhealthy. Greatly increases risk builders won=
't
>
>
> take action. Increases risk you won't research it thoroughly.
>
>
>
> A healthy response would be:" Here's another example of how our engines
>
> produce unusually destructive exhaust temperature and pulses. We have a
> rich
>
>
>
> history of broken exhaust components. We need to be very thorough when
>
> designing and building exhaust."
>
>
>
> I designed my own muffler. It had two inlets, two outlets. So if (when) m=
y
>
> muffler failed, it could never block both pipes. I also put loose safety
>
> wire around my pipes, because on a pusher loosing pipe wipes out prop. So
>
> basically, I assume stuff will fail, then design it to control the way i=
t
>
> fails. I've heard of rotary guys doing same type of thing. This is a good
>
> time to share those key items.
>
>
>
> On your car, they deliberately design products to fail a certain way. The=
y
>
> will make a component weak, so it fails first. They do that with wheels a=
nd
>
>
> hubs. So when the muffler fails, little pieces come apart, not big
> sections?
>
>
>
> You guys do a great job of sharing successes, design and construction
>
> details. This is another opportunity.
>
>
>
> -al wick
>
>
>
>
>
>
>
>
>
> <No doubt you are on the money, Rusty. When folks are already predispose=
d
>
> to bad mouth the rotary - this will only be more ammunition. "See! even
>
> with umpteen million dollars you can't get one to fly" {:>). But, I
>
> serious doubt it will effect many who have researched the rotary and come
> to
>
>
>
> understand its benefits - as for the rest, who cares {:>)
>
> >
>
>
>
> I'm certain it was a relief to Mistral that the culprit was not one of
>
> their engine components.
>
>
>
>
>
>
>
> Whew! a close one for sure.
>
>
>
>
>
>
>
> Hi Ed,
>
>
>
>
>
>
>
> Unfortunately, I bet the majority of people will only hear "Mistral
>
> rotary", "lost power", and "crash" :-(
>
>
>
>
>
>
>
> Rusty (RV-3 taking forever.)
>
>
>
> ____________________________________________________________
>
> Orlando Vacations - Click Here!
>
>
> http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3nK7u59LkagfZ5IcEgGqYcv=
PRC
>
> wA85GgQITbFK9vE7wPGKFP/
>
>
>
> --
>
> Homepage: http://www.flyrotary.com/
>
> Archive and UnSub:
>
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
>
------=_Part_17199_10570541.1212982470830
Content-Type: text/html; charset=WINDOWS-1252
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
<div>As always Al, probably the best flying example I have seen!</div>
<div> </div>
<div>-- <br>David Leonard<br><br>Turbo Rotary RV-6 N4VY<br><a href=3D"http:=
//N4VY.RotaryRoster.net">http://N4VY.RotaryRoster.net</a><br><a href=3D"htt=
p://RotaryRoster.net">http://RotaryRoster.net</a> <br><br></div>
<div class=3D"gmail_quote">On Sun, Jun 8, 2008 at 1:14 PM, Al Gietzen <<=
a href=3D"mailto:ALVentures@cox.net">ALVentures@cox.net</a>> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"PADDING-LEFT: 1ex; MARGIN: 0px 0=
px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<div lang=3D"EN-US" vlink=3D"purple" link=3D"blue">
<div>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">Exhaust and muffler design in the rotary installation is on=
e of the more complex of all the installation issues. There are, and have b=
een so many variations among the various installations that there is little=
statistical proof of anything. I'll add a few comments and opinions =
that may be relevant, and describe what I did. It may trigger some ideas fo=
r you to think about. My system on the 20B is now approaching 100 hours =96=
not a long term proof =96 but it is still solid. </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">The exhaust temps out of the port are very high, typically =
in the neighborhood of 1600F, and sometimes maybe 1700F. Couple this =
with pressure pulses and vibrational loads, and corrosive environment, and =
you have a very demanding situation. When you look at material proper=
ties to handle this, things narrow down pretty rapidly, particularly if you=
also want light weight as we do in aviation. Stainless steels, like =
321, can handle the temps and be a workable exhaust =96 but, design for low=
stress levels then becomes a must, because SS are subject to 'stress corro=
sion' at these temps. Combine the high temperatures and vibrational s=
tress and you get inter-granular corrosion which weakens the material and i=
t eventually falls apart.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">On way to alleviate that is to use inconel. It gives =
you higher temperature capability and corrosion resistance. And it gi=
ves you higher cost. But is it worth it to reduce your risk a forced =
landing in an unfriendly place? Compared to the total cost of your ai=
rplane it's a small amount. Maybe cut cost somewhere where it is less=
critical to safety. </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">Another thing to consider is that the more quickly you can =
expand the exhaust gas, the more quickly you can deal with lower temperatur=
es. Charles Law =96 temp (degree K) goes down in direct proportion to=
increased volume. This becomes more complex in an exhaust system bec=
ause of other factors, but it still works in your favor. The gas will=
expand down a constant diameter pipe, but expanding into a BIG pipe can ma=
ke a significant drop. </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">That can be one of the advantages of the tangential muffler=
/manifold, or the design that Neil presented. The amount of the temp =
drop of course depends on the pressure in that bigger can. These designs ha=
ve their own possible failure modes associated with welded joints and therm=
al stresses, but at least there is nothing there that is going to plug up t=
he flow downstream. The skill of the welder and the post-weld heat tr=
eatment are important factors.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">These units are generally bolted directly to the engine via=
the short header pipes, so vibration loads are a factor. Ideally you'd lik=
e to have stress (and thermal expansion) de-coupling between the engine and=
the muffler/manifold, but since the engine can move relative to it's mount=
you either have to accommodate significant movement, or support it to the =
engine by some other means then the header pipes.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">And then there is the matter of the exit pipe(s) and second=
ary mufflers. Those have to be supported as well =96 an unsupported length =
of pipe extending from the muffler is an ideal candidate for some vibration=
al resonance which will fail the system somewhere. And the further away fro=
m the engine centerline, the greater the loads. </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">My exhaust system is shown in the first attached photo. Thi=
s is in a pusher configuration. It is an inconel tangential manifold/=
muffler supported to the engine by short inconel header pipes which are wel=
ded to a heavy RB steel flange. It has a convex 'head' at the front, and a =
conical outlet to the exit pipe. It has internal vanes welded at an a=
ngle on the inside surface opposite the exit from the headers (you can see =
the welds on the outside) to help break up the pulses and direct the exhaus=
t toward the exit. They also prevent possible "swirl-flow choking" which co=
uld increase back pressure. There are 'straightening' vanes in the co=
nical exit section.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">The exit pipe is clamped (custom heavy SS clamp) to the inl=
et pipe of the secondary muffler (I'll call it a resonator). The reso=
nator is also of my design and is made of 321 SS. It is basically a s=
traight through 2 =BE" pipe that is drilled full of =BC" holes (about 100),=
contained within outer 5" dia. pipe. The inner pipe has an orifice p=
late at the center which has a 1 5/8" opening. This orifice produces =
some restriction to the flow through the resonator to force some of it outw=
ard through the holes, and back through the holes to exit. The purpos=
e of the resonator is to knock down the pressure peaks a bit more. Me=
asurements on the dyno showed that resonator knocked another 8 db off the s=
ound level and had no noticeable effect on the HP.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">The plug in the resonator closes a port originally intended=
for the O2 sensor. But it didn't work well in that location because the te=
mperature was too low (interesting, huh). I had to move it to the inlet pip=
e.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">Last but not least, there is a SS support at the end which =
clamps solidly to the redrive. The clamp is designed to be rigid laterally,=
but to also be an effective heat choke. This supports the resonator,=
and reduces the likelihood of any resonance vibration in the system.</span=
></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">I originally thought that the resonator internals may not l=
ast more than 50 hours, but at 95 hours they are still solid. Which brings =
up another point. It is easily inspected. I can see those internals f=
rom the exit end, and I can stick a screwdriver or ratchet handle or whatev=
er; in there and bang around to be sure things are sound. I inspect a=
ll the welds in the exhaust system every time I remove the cowl, or at leas=
t every 10 hours or so. Make your system inspectable, and keep an eye=
on it.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">I wouldn't call it "quiet", but I've had people say they li=
ke the way it sounds. Time will tell its reliability.</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">Best,</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana">Al Gietzen</span></font></p>
<p><font face=3D"Verdana" size=3D"2"><span style=3D"FONT-SIZE: 11pt; FONT-F=
AMILY: Verdana"> </span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> &=
nbsp; If you go throu=
gh the archives, you'll find lots of examples of</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">failed =
muffler designs. Many by your's truly. I think I've tri=
ed every</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">concoct=
ion known to man and the Swiss. They all worked... for a while.=
</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> &=
nbsp; My best overall=
design (see attached) is a 2" tube, full of holes</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">inside =
a 5" tube. All made of 16ga SS, all welded together. Needl=
ess to</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">say, th=
e flange is more like 3/16" - 1/4" SS. The inside end of th=
e 2" tube</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">is weld=
ed to the end cap of the 5" tube. That blocks off the one end of=
the</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">2"=
tube and secures it from movement. The exhaust end of the 2" tu=
be is</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">welded =
through a 2" hole in the other 5" end cap. Rather than dril=
ling the</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">2"=
tube full of round holes, we cut slots with a saw. Then take a big f=
lat</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">blade s=
crewdriver, stick it in the slot and bend it over. This creates an</s=
pan></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">oblong =
hole. (Much easier than drilling into SS. This is what will go =
on</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">the Vol=
mer.</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> &=
nbsp; The sound is qu=
ite acceptable, it fits inside the cowl and Jim M.'s</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">version=
lasted the life of the aircraft... 600+ hours.</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Neil</s=
pan></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">PS: Are=
you considering </span></font>Rough River?</p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">-----Or=
iginal Message-----</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">From: R=
otary motors in aircraft [mailto:<a href=3D"mailto:flyrotary@lancaironline.=
net" target=3D"_blank">flyrotary@lancaironline.net</a>] On</span></font></p=
>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Behalf =
Of Al Wick</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Sent: <=
/span></font>Saturday, June 07, 2008 4:57 PM</p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">To: Rot=
ary motors in aircraft</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Subject=
: [FlyRotary] Re: Mistral Crash Analysis</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">C'm=
on guys. You do this every time there's a crash. Instantly go into </sp=
an></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">rationa=
lization mode. It's unhealthy. Greatly increases risk builders won'=
t </span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">take ac=
tion. Increases risk you won't research it thoroughly.</span></font></p=
>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">A healt=
hy response would be:" Here's another example of how our engines <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">produce=
unusually destructive exhaust temperature and pulses. We have a rich</span=
></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">history=
of broken exhaust components. We need to be very thorough when </span></fo=
nt></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">designi=
ng and building exhaust."</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">I desig=
ned my own muffler. It had two inlets, two outlets. So if (when) my </span>=
</font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">muffler=
failed, it could never block both pipes. I also put loose safety </span></=
font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">wire ar=
ound my pipes, because on a pusher loosing pipe wipes out prop. So </span><=
/font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">basical=
ly, I assume stuff will fail, then design it to control the way it </=
span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">fails. =
I've heard of rotary guys doing same type of thing. This is a good </sp=
an></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">time to=
share those key items.</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">On your=
car, they deliberately design products to fail a certain way. They </span>=
</font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">will ma=
ke a component weak, so it fails first. They do that with wheels and </span=
></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">hubs. S=
o when the muffler fails, little pieces come apart, not big sections?</span=
></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">You guy=
s do a great job of sharing successes, design and construction </span></fon=
t></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">details=
. This is another opportunity.</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">-al wic=
k</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"><No =
doubt you are on the money, Rusty. When folks are already predisposed=
</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">to bad =
mouth the rotary - this will only be more ammunition. "See! even=
</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">with um=
pteen million dollars you can't get one to fly" {:>).&nbs=
p; But, I </span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">serious=
doubt it will effect many who have researched the rotary and come to</span=
></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">underst=
and its benefits - as for the rest, who cares {:>)</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">></s=
pan></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> =
I'm certain it was a relief to Mistral that the culprit was not one of =
</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">their e=
ngine components.</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> =
Whew! a close one for sure.</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> =
Hi Ed,</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> =
Unfortunately, I bet the majority of people will only hear "Mistral </=
span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">rotary&=
quot;, "lost power", and "crash" :-(</span></font=
></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> =
Rusty (RV-3 taking forever.)</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">_______=
_____________________________________________________</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Orlando=
</span></font> Vacations - Click Here!</p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"><a href=
=3D"http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3nK7u59LkagfZ5IcEgGqY=
cvPRC" target=3D"_blank">http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i=
3nK7u59LkagfZ5IcEgGqYcvPRC</a></span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">wA85GgQ=
ITbFK9vE7wPGKFP/</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"> <=
/span></font></p><font color=3D"#888888">
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">--</spa=
n></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Homepag=
e: <a href=3D"http://www.flyrotary.com/" target=3D"_blank">http://www=
.flyrotary.com/</a></span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt">Archive=
and UnSub:</span></font></p>
<p><font face=3D"Nimrod" size=3D"2"><span style=3D"FONT-SIZE: 11pt"><a href=
=3D"http://mail.lancaironline.net:81/lists/flyrotary/List.html" target=3D"_=
blank">http://mail.lancaironline.net:81/lists/flyrotary/List.html</a></span=
></font></p>
</font></div></div><br>--<br>Homepage: <a href=3D"http://www.flyrotar=
y.com/" target=3D"_blank">http://www.flyrotary.com/</a><br>Archive and UnSu=
b: <a href=3D"http://mail.lancaironline.net:81/lists/flyrotary/List.=
html" target=3D"_blank">http://mail.lancaironline.net:81/lists/flyrotary/Li=
st.html</a><br>
<br></blockquote></div><br><br clear=3D"all"><br>
------=_Part_17199_10570541.1212982470830--