X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) From: "lehanover lehanover@aol.com" Received: from sonic305-2.consmr.mail.bf2.yahoo.com ([74.6.133.41] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 823532 for flyrotary@lancaironline.net; Sun, 11 Oct 2020 11:27:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.6.133.41; envelope-from=lehanover@aol.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1602430053; bh=/ggjiG/oGd7CzqV/IX/SMq9pjTzHAqZKjck5cPOaPos=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=ho+OFXOiT5bmGIaTgH+JC1HlcmCeQxvsh8F52yywlkU+eBV7Z3oUAtDnLeADGiTHbxZNYEM3LaCasteHFZIpI6FsruOVuGE5zZdFRSFs6ta1TMGnxXdEILdiuKGSvklRX0bc8RSgYWw373g6uMhUzp0hE4pPvDs9Lbhea07ljBrkp3Kkqjv9HgFUztOOZcwpOcqB+MCLWGDHp5vp42lPyK6QRxu7eVvNSJSCqP9FVHVmg3g9SSeph5oI4C7yr+Tgh0hqFj/GNJ9gpxKCXiRH3/jSuX86yf6dHRG0DjxCv8FZSfh3Mnin4lZX22cXpH29oRD8smVr7Lfnod+XZML0KQ== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1602430053; bh=lzii/T1FOai7HFgVuRkaakOAqRUApC33bCnQkayBrTs=; h=Date:From:To:Subject; b=ncjjXDFYo7sP1b8YdCFtyWNWiIQDY+Knyg9uD0mC8CdGNklH4nkzYjsBYjokP+KnOTuHG/tW8lFzcopB6nCmLL9+RjHjvf2/uc2ituZ8mT7lEmYh73AGSuktuGYajYRWgKimQ/s8Zhtlvx6kUIeparWXYZZtCa0uEnZL5asYAPZ63xv8nmH3IwuHty7veet1/GTy4oEF9DP6XcPd60x71k16pp0FpXmSZNAFPpNASBJhMppMIoNLJ/YOf51mh8ldysfaQ9GPkHZreK9JpBy/bwszEjqVxZoZyUpMDhn/7cJd5hfwNp3om8Tkc5iiotMVHUrvUi4iHtOiSWTRgrzQqg== X-YMail-OSG: jkkDg9wVM1nYx.DYbaXUZcmoYmHVvXgaQIHNcFUeo.2sEn9.j5oRQZcBSsfKib. jMEBlGreGAknfwJYPJEwO60avZD3064AxrIpvBn7FfBCIj_TE7aOT4eL7SrH81i4SbrSKoIVq0BO oNfRf_OsPgA8WoyMjf2sDis_YMb0p.xH1UzNJumNaJTFAc.ilW_pRcvk1sxzk40Rb30G0k3Vw5ZD 7v7ajIXaeorTB2_LGcZ5NRXfk6DWDl_eJsLCHk6M8BrWQejo1U1vrz8jbNZOlKR9RYL2y7n5ePLP MubrgJkGkajGif8pyGPrGeSb8SW8hYBqCJYUWLiJqns58SqHPHCfDetjyhUzXuTf1KlRgaNhJLr4 _OujpQZt5xsCVlk_H8EkZak0NQX5CIBfv4EhSZEUAbW5RsoI7BgIAf1S_C3tgC8Ssn5gaFeGTYV_ GfSUKxq7AL226WIyjfX7VUJa.mKeFsZbmyoxXyZ3Vl.l53_BpNsH.FdXFT1NS9VJu2FGxsOlxe_1 JoHpMsjTfG7BXcPjM9GRPU.ErYYHRj0TjbtU6Zk6ZYgIZK8dj4O_Q8eWXKR3dYaHNUKRW.cuhHaz a9aRbo78pJGkNBrnWW3ydy.gpLkFSTTnH9yPxi55uPJOF8JiqhKERTnEtZrIkwPP43JVGAqTp0DA AamRQys_3jjfZIBKHpyZnoJNgOWoJ0zbMCieKV40pcaKd5QuqRpjNGDwEpQULTOMYtnEwntXPZZF YUOsLKdSSfpvB.byWolj5rZWo15Ciwp8W3wg40QecQL58l3ltWCQutVs3SEJhjApPuOyHPuww5yO PAkWYpI7AxYw89EnU.3lZ0XwPnoN.MPtoCg9Ue9Z1bVWnYbNo7jO7rOH.JL71v2_1tf4nFl1Xc6r uvl5DHuSpcndQk8USc4gO_mvyqTRIZO48yJGe8Blq8uKl8UpbGzPfwv5Ft6r_aq99b1gjR7TRcV_ gAM393l2_VZ9Q5a5_2MUkbw8Q8WC..V34YGxv17ghvEhVftgzcxgAoMxi4iBhbKTuRPU8H7DY1de Q9KrH9ztkmSu4b2rPKkK7fvcdgsv2j2kzDjR9vESuE2wDcBmLqkdaPkza7U0fOR2HxJ8ca1RGigR Nm2rHwRnkOzBKF9MPEFCM5U7OgLUYMJXbnzkVbyq5.17Hfb1t6Krlr5hmsZD.ZeWrETr1Htcd_t9 Q.yHXCIPvux62VJdhhNGRC3ZXUlprKrPDRPUr3FDNExMtAJpOy4W_qBnNJZC45ygqZ3Qovct9n2S jXMMiNsRzXRawRA95CIpHCqxlxokxM4TFZbUm._ZHVzsLaLfkqJX.huO4_5HMA9n0omLSMyhU.jK vHCJpcz0SccdF9FT4s3tQ5y6Ip1fcIQbJclSf9EIujVA1XJ0ztoKJ6ZGLjHMqAguw5gXnz18.fsC bmNbO3j28PtE3Hyov9BzdPCS4yb5h0wMkVb_rb8XZc23pdH4IynAoL0gpFp0A_G9Q_vo0WiU- Received: from sonic.gate.mail.ne1.yahoo.com by sonic305.consmr.mail.bf2.yahoo.com with HTTP; Sun, 11 Oct 2020 15:27:33 +0000 Date: Sun, 11 Oct 2020 15:27:29 +0000 (UTC) Reply-To: lehanover To: flyrotary@lancaironline.net Message-ID: <1352530326.217226.1602430049334@mail.yahoo.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: Mufflers MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_217225_1478075209.1602430049329" X-Mailer: WebService/1.1.16795 aolloki unknown Content-Length: 44065 ------=_Part_217225_1478075209.1602430049329 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Way back in olden times....Radial engines had a strain gauge rigged across = the gap between the engine mount and the engine. Thus the amount of twist t= he engine applied to the mount through the Lord Mounts could be deduced. Th= us total torque times RPM over 5252 =3D HP. The flight engineer could then = tell the pilot about where we would crash, and phone for help in advance...= ........In C-119s.....A simple thing.Lynn E. Hanover=C2=A0In a message date= d 10/7/2020 11:21:05 AM Atlantic Standard Time, flyrotary@lancaironline.net= writes:=C2=A0 Check with (join) area EAA chapters. Our chapter has owned one for years; w= e also have a set of a/c scales. Charlie On 10/7/2020 7:49 AM, Finn Lassen finn.lassen@verizon.net wrote: Prop balancing was my first thought too. Engine will not vibrate unless you've got faulty ignition, intake problems = or similar. I'm my RV-4 I won't have to torque down Berry mounts. I don't have any. Tra= cy talked me out of using them. That, of course, makes prop balancing essential. I'm currently fitting the = spinner to the RV-4 -- perhaps a few more days. There's a place where one c= an rent a dynamic prop balancer for a week for $150. Perhaps we could share= the cost?=20 Finn On 10/6/2020 9:29 PM, Matt Boiteau mattboiteau@gmail.com wrote: It's 42miles as the crow flies. I got the normal 25nm increased to 45nm.=C2= =A0 Now that I'm flying, I'll update the group on my progress. 8 hours in. I th= ink the exhaust is shaking the plane, I was hoping the engine be a smoother= plane ride. What do people torque down the Berry mounts to, really tight t= o compress? - Matt Boiteau On Wed, Sep 30, 2020 at 2:02 PM Finn Lassen finn.lassen@verizon.net wrote: Hey, I'm just a stone-throw away (9FL5). Surely your test area is includes = that? You're welcome to stop by. Finn On 9/30/2020 8:59 AM, Matt Boiteau mattboiteau@gmail.com wrote: Williston (X60 airport) I'll be there from Oct 3rd to 29th, to fly off my 25hours. So far I have 6 = hours and had to increase my oil inlet duct size, and redo the exhaust so I= could hear. We'll see what new bugs will pop up. I'll be posting a lot to = keep people in the loop and help me along the way. If people want to visit in person to check out the setup and give me advice= , I'm all ears. =C2=A0 - Matt Boiteau On Wed, Sep 30, 2020 at 5:38 AM lehanover lehanover@aol.com wrote: Where in Florida? I live in Florida in the winter.=C2=A0 =C2=A0Lynn E. Hano= ver=C2=A0In a message dated 9/30/2020 12:48:34 AM Atlantic Standard Time, f= lyrotary@lancaironline.net writes:=C2=A0 I've been stuck in Canada far too long. Finally flying to Florida on Sat to= see my plane and start flying off the hours (trouble free I hope) my email is my name (without spaces) at normal gmail dot com. - Matt Boiteau On Tue, Sep 29, 2020 at 3:02 PM Bobby J. Hughes bhughes@qnsi.net wrote: Matt, =C2=A0 Did you make it back to Canada in time for the first snow? I would like to = discuss your MS install off list when you have time. =C2=A0 Bobby =C2=A0 =C2=A0 =C2=A0 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]=20 Sent: Wednesday, July 08, 2020 7:10 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Mufflers =C2=A0 Sadly, by the time the welder and I finished, I only got about 2 hours on t= he plane before I had to pack up my winter trip. I was planning to go back = in March to FL (I live in Canada) to start flying off the 25 hours, but you= know how that all went. So I'm just sitting here waiting for the borders t= o open up and fly my plane! Early conclusion is it worked pretty darn good. I'd say I'm equivalent=C2= =A0to an IO-360, maybe a tad quieter. Also on ground testing only, I quickl= y mocked up a long tube under the plane with holes drilled in it (with the = end capped off), and it pretty much got rid of all the engine noise, only p= rop noise. Haven't flown with that yet. One thing I still want to do is tes= t the backpressure. Making sure the CAN has enough holes inside. The best price I found on 321 was from ProFabrication. I went with 2.75" 20= ga (0.035") on the downpipe & outlet. https://www.profabrication.com/index.php/products/straight-tubing/321-stain= less-steel.html I did use SPD Exhaust for the double slip joints at the primaries and downp= ipe. 2" 16ga (0.06") http://www.spdexhaust.com/pdfs/22-23_Tubing.pdf=C2=A0=C2=A0 For the CAN, McMasterCarr 24"x24" 18ga (0.05") rolled into I think a 5 or 5= .5" can. You can go heavier ga, I just guessed.=C2=A0 https://www.mcmaster.com/1754T51/=C2=A0=C2=A0 - Matt Boiteau =C2=A0 =C2=A0 On Wed, Jul 8, 2020 at 2:35 PM Bobby J. Hughes bhughes@qnsi.net wrote: I=E2=80=99m at the exhaust header stage in my S21 FWF build. I=E2=80=99m co= nsidering a traditional header, =C2=A03-1 merge collector with 1.75=E2=80= =9D primaries to a 2.5=E2=80=9D tube. I=E2=80=99m trying to be very weight = conscious and looking for possible alternatives. The CA manifold can likely= be built for nearly the same weight as the header design in the picture. I= =E2=80=99m a little concerned with the tangential design. Mark S built and = tested one on his 20B. It ran hot and caused the outer water jacket seals t= o fail. Mark was not running a wideband so he couldn=E2=80=99t see a clear = relationship between F/A and EGT=E2=80=99s.=C2=A0 He may have be running at= or near peak EGT=E2=80=99s. EGT=E2=80=99s for the renesis can be kept to b= etween 1500F -1600F with a little extra or a little less fuel. I will like = install the coolant radiator on the belly so adding an external muffler wou= ld keep it off centerline.=20 =C2=A0 I have located some reasonable priced Inconel 625 0.040 sheets. If rolled i= nto a 5-6=E2=80=9D tube, would this thickness be sufficient for a muffler s= hell or the CA / tangential manifold tube? =C2=A0 Matt, =C2=A0 How is your CA header holding up? =C2=A0 Thanks, =C2=A0 Bobby =C2=A0 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]=20 Sent: Saturday, January 25, 2020 7:53 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Mufflers =C2=A0 Okay so after 2 full days of having our welder out, finally brought the CAD= design to life. Except both days were all nighters, so I was too tired and= busy to take 'in progerss' pictures. Was tricky to build, which made the h= ourly welding cost sky high, more then the engine itself. Hopefully that me= ans I can save money in the future on hearing aids. Thanks Charlie for the tip on the=C2=A0spectrum analyzer. I didn't get any = before numbers, but it's all low Hz now. That harsh high pitch is gone. Db'= s are still there, but I'd say with just the muffler design, it's comparabl= e to=C2=A0typical=C2=A0lycoming. I can start to hear the prop noise over th= e engine noise. I measured back pressure around 3.5psi @ 2200rpm prop. I ran out of time to flight test the long pipe under the airplane. I quickl= y held it up with my hands and the exhaust pretty much disappeared with the= prop taking over the noise. Before flying, I want to add backpressure gaug= e to that part and drill holes to find a balance between backpressure and n= oise. =C2=A0 SO the "header" muffler should make quite like any other plane, and the "un= der belly" pipe will make you standout in=C2=A0silence. =C2=A0 Since this email type newsletter is from the=C2=A0dinosaur=C2=A0ages, I'll = add pictures and video=C2=A0to=C2=A0https://www.homebuiltairplanes.com/foru= ms/threads/exhaust-within-subcowl.30848/page-2#post-512762 =C2=A0 - Matt Boiteau On 2020-01-18 5:29:51 PM, Matt Boiteau wrote: Have started on the exhaust. Made all three primaries 2" double slip joints= (that alone took almost a whole day with welder). The big can (CA -=C2=A0C= entrifugal Accumulator) rolled into a 5" can and we'll secure it to the eng= ine with straps. The inside pipe is 2.75" which has an area of 5.94sq". I'm not sure if ther= e's a magic number, but all the holes I drilled equaled to just under doubl= e the area (11sq"). Most are 3/8, but I did add some 1/2 to get the total a= rea up.=C2=A0Could we get away with drilling less holes? Not sure. I'll be = able to drill out one side end of the CA and pull out the inner tube and ch= ange out. Will=C2=A0experiment=C2=A0later=C2=A0with less holes and monitor = back pressure. Will weld a npt bung on the CA and use the wideband bung to = measure the different. The previous exhaust with just an=C2=A0Aero Turbine 2525XL, measured ~113dB= A. With nothing, was closer to 120dBA. Funny around 2000 prop rpm was loude= r then at 2300 full static.=C2=A0 Error! Filename not specified. =C2=A0 - Matt Boiteau On 2020-01-07 12:19:23 AM, Matt Boiteau mattboiteau@gmail.com wrote: Okay I'll make all 3 primary tubes (2" diameter) all double slip fit. Weldi= ng=C2=A0batwing=C2=A0tabs (picture below) on to either side on the slips, w= ill hold the muffler to the header but allow expansion. =C2=A0 Having troubles finding 2.75" bends in 321, so I might have to just switch = to 3" downpipe that is more common. Vband clamp before downpipe for easier = removal and under the plane to allow adding additional exhaust setups (long= pipe with holes drilled in it, fishmouth tailpipe, etc) I found a company that makes flex bellows in 321. I'm just not sure if I sh= ould have it vertical on the downpipe or close to the muffler horizontal be= fore the first 90degree bend downwards. https://www.aceraceparts.com/products/3-000-flex-bellow-assembly-321-stainl= ess?variant=3D11067135556 Error! Filename not specified. =C2=A0 =C2=A0 Batwing tabs Error! Filename not specified. =C2=A0 - Matt Boiteau On 2020-01-03 4:22:18 PM, Neil Unger 12348ung@gmail.com wrote: Mat, =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0 As usual I have no idea.=C2=A0 I made all 3 sli= p joints and to date no grief in that area.=C2=A0 I am coming around to the= stock manifold in some way.=C2=A0 Yes it is heavy, but appears to muffle t= he noise as well.=C2=A0 Know of 2 installations that use the stock manifold= with a simple muffler after and both claim "acceptable" noise. It appears = that the stock manifold has a big influence on noise??=C2=A0 Would prefer a= DB reading, but if not available it is what it is.=C2=A0 All is compromise= , weight, cost, time, but at the end of the day it has to work.=C2=A0=20 Still working on the turbo even though the world is on holidays.=C2=A0 All = to save my hearing.=C2=A0 So far the rotary is definitely "unique" as far a= s a turbo is concerned.=C2=A0 The heat generated exceeds all else=C2=A0 Two= things to date -- special exhaust wheel and water cooled bearing body =3D,= all for heat.=C2=A0 Have modified the stock front plate on the renesis to = take an electric water pump.=C2=A0 That is the simple bit. Neil. On 1/4/2020 5:37 AM, Matt Boiteau mattboiteau@gmail.com wrote: okay I found a good company called SPD Exhaust. They have everything you ne= ed in 321ss. With the engine being an RX8, we have three exhaust ports. Should I weld th= e front and back solid to the muffler, and make the middle one a slip fit f= or expansion? Or vice-vesa? Error! Filename not specified. =C2=A0 - Matt Boiteau On 2019-12-28 11:03:42 AM, Finn Lassen finn.lassen@verizon.net wrote: I did something similar with my RV-3 13B decades ago. It split open at the = welds around one of the pipes from the manifold into the the big outer tube= True, it did use individual manifold base plates, not the connected factor= y manifold and the big tube was only 0.035. Still, I would recommend slip joints on two of the three pipes, like I adde= d on one of the pipes (cut through and a surrounding bigger pipe -- missing= in picture). Error! Filename not specified. Can't remember why I went from the above to individual runners into a perfo= rated pipe under the fuselage. Probably got lured by promise of increased p= ower by tuned lengths and still uncomfortable by the muffler being inside t= he cowling. Finn On 12/28/2019 12:10 AM, Matt Boiteau mattboiteau@gmail.com wrote: This is what I'm going to try in a few weeks.=C2=A0=20 "Exhaust valve opens and a pulse of hot gas puffs out through a short pipe,= then=C2=A0tangentially=C2=A0into a cylindrical canister. Being tangential,= the pulse flattens out and travels=C2=A0helically=C2=A0(rather than bounci= ng and reverberating around) along the inside curved wall of the can, spira= ling toward the exit, where it comes out more uniform in flow and so pretty= quiet." =C2=A0 Outer pipe =3D 321 ss 0.050 thick. Flat plate bent to a 5" tube Inner pipe =3D 321 ss 0.036 thick. 2.5" diameter (I might use 302ss 0.065 since I already have it) =C2=A0 >From my understanding, the area of the holes should be double the area of = the inner pipe.=C2=A0 =C2=A0 - Matt Boiteau =C2=A0 | | Virus-free. www.avast.com | ------=_Part_217225_1478075209.1602430049329 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Way back in olden times....Radial engines had a strai= n gauge rigged across the gap between the engine mount and the engine. Thus= the amount of twist the engine applied to the mount through the Lord Mount= s could be deduced. Thus total torque times RPM over 5252 =3D HP. The fligh= t engineer could then tell the pilot about where we would crash, and phone = for help in advance...........In C-119s.....A simple thing.
Lynn E. Hanover
 
In a message dated 10/7/2020 11:21:05 AM Atlantic Standard Time, flyrotary@= lancaironline.net writes:
 
Check with (join) area EAA chap= ters. Our chapter has owned one for years; we also have a set of a/c scales= .

Charlie

On 10/7/2020 7:49 AM, Finn Lassen finn.lassen@verizon.net wr= ote:
Prop balancing was my first tho= ught too.

Engine will not vibrate unless you've got faulty ignition,= intake problems or similar.

I'm my RV-4 I won't have to torque down= Berry mounts. I don't have any. Tracy talked me out of using them.

= That, of course, makes prop balancing essential. I'm currently fitting the = spinner to the RV-4 -- perhaps a few more days. There's a place where one c= an rent a dynamic prop balancer for a week for $150. Perhaps we could share= the cost?

Finn

On 10/6/2020 9:29 PM, Matt Boiteau mattboiteau@gmail.com wrote:
It's 42miles as the crow flies. I got the normal 25nm incr= eased to 45nm. 
Now that I'm flying, I'll update the group on my pr= ogress. 8 hours in. I think the exhaust is shaking the plane, I was hoping = the engine be a smoother plane ride. What do people torque down the Berry m= ounts to, really tight to compress?

- Matt Boiteau

On Wed, Sep 30, 2020 at = 2:02 PM Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:
Hey, I'm just a stone-throw away (9FL5). Surely your test area is incl= udes that?
You're welcome to stop by.

Finn

On 9/30/2020 8:= 59 AM, Matt Boiteau mattboiteau@gmail.com wrote:
Williston (X60 airport)
I'll be there from Oct 3rd to 2= 9th, to fly off my 25hours. So far I have 6 hours and had to increase my oi= l inlet duct size, and redo the exhaust so I could hear. We'll see what new= bugs will pop up. I'll be posting a lot to keep people in the loop and hel= p me along the way.

If people want to visit in person to check out t= he setup and give me advice, I'm all ears.
 
- Matt Boiteau

On Wed, Sep 30, 2020 at = 5:38 AM lehanover lehanover@aol.com <flyro= tary@lancaironline.net> wrote:
Where in Florida? I live in Florida in the winter.&nb= sp;  Lynn E. Hanover
 
In a message dated 9/30/2020 12:48:34 AM Atlantic Standard Time, flyrotary@lancaironline.net writes:
 
I've been stuck in Canada far too long. Finally flying to = Florida on Sat to see my plane and start flying off the hours (trouble free= I hope)
my email is my name (without spaces) at normal gmail dot com.
- Matt Boiteau

On Tue, Sep 29, 2020 at 3:02 PM Bobby J. Hughes bhu= ghes@qnsi.net <flyrotary@lancaironline.net>= wrote:

Matt,

 

Did you make it back to Canada in time for the first snow? I wou= ld like to discuss your MS install off list when you have time.

 

Bobby

 

 

 

Rotary motors in aircraft [mailto:flyrotar= y@lancaironline.net]
Sent: Wednesday, July 08, 202= 0 7:10 PM
To: Rotary motors in aircraft
Subj= ect: [FlyRotary] Re: Mufflers

 

Sadly, by the time the welder and I finished, I only got about 2 hours o= n the plane before I had to pack up my winter trip. I was planning to go ba= ck in March to FL (I live in Canada) to start flying off the 25 hours, but = you know how that all went. So I'm just sitting here waiting for the border= s to open up and fly my plane!

Early conclusion is it worked pretty = darn good. I'd say I'm equivalent to an IO-360, maybe a tad quieter. A= lso on ground testing only, I quickly mocked up a long tube under the plane= with holes drilled in it (with the end capped off), and it pretty much got= rid of all the engine noise, only prop noise. Haven't flown with that yet.= One thing I still want to do is test the backpressure. Making sure the CAN= has enough holes inside.

The best price I found on 321 was from Pro= Fabrication. I went with 2.75" 20ga (0.035") on the downpipe & outlet.<= br>http://www.spdexhaust.com/pdfs/22-23_Tubing.pdf  
For the CAN, McMasterCarr 24"x24" 18ga (0.05") rolled into I think a 5= or 5.5" can. You can go heavier ga, I just guessed. 
https://www.mcmaster.com/1754T51/  

=

- Matt Boiteau

 

 

On Wed, Jul 8, 2020 at 2:35 PM Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironlinenet> wrote:

I’m at the exhaust header stage in my S21 FWF build. I&rsq= uo;m considering a traditional header,  3-1 merge collector with 1.75&= rdquo; primaries to a 2.5” tube. I’m trying to be very weight c= onscious and looking for possible alternatives. The CA manifold can likely = be built for nearly the same weight as the header design in the picture. I&= rsquo;m a little concerned with the tangential design. Mark S built and tes= ted one on his 20B. It ran hot and caused the outer water jacket seals to f= ail. Mark was not running a wideband so he couldn’t see a clear relat= ionship between F/A and EGT’s.  He may have be running at or nea= r peak EGT’s. EGT’s for the renesis can be kept to between 1500= F -1600F with a little extra or a little less fuel. I will like install the= coolant radiator on the belly so adding an external muffler would keep it = off centerline.

 

I have located some reasonable priced Inconel 625 0.040 sheets. = If rolled into a 5-6” tube, would this thickness be sufficient for a = muffler shell or the CA / tangential manifold tube?

 

Matt,

 

How is your CA header holding up?

 

Thanks,

 

Bobby

 

Rotary motors in aircraft [mailto:flyrotar= y@lancaironline.net]
Sent: Saturday, January 25, 2= 020 7:53 PM
To: Rotary motors in aircraft
Su= bject: [FlyRotary] Re: Mufflers

 

Okay so after 2 full days of having our welder out, finally brought = the CAD design to life. Except both days were all nighters, so I was too ti= red and busy to take 'in progerss' pictures. Was tricky to build, which mad= e the hourly welding cost sky high, more then the engine itself. Hopefully = that means I can save money in the future on hearing aids.

Thanks Ch= arlie for the tip on the spectrum analyzer. I didn't get any before nu= mbers, but it's all low Hz now. That harsh high pitch is gone. Db's are sti= ll there, but I'd say with just the muffler design, it's comparable to = ;typical lycoming. I can start to hear the prop noise over the engine = noise. I measured back pressure around 3.5psi @ 2200rpm prop.

I ran = out of time to flight test the long pipe under the airplane. I quickly held= it up with my hands and the exhaust pretty much disappeared with the prop = taking over the noise. Before flying, I want to add backpressure gauge to t= hat part and drill holes to find a balance between backpressure and noise.<= /span>

 

SO the "header" muffler should make quite like any other plane, and = the "under belly" pipe will make you standout in silence.

 

Since this email type newsletter is from the dinosaur ages= , I'll add pictures and video to ht= tps://www.homebuiltairplanes.com/forums/threads/exhaust-within-subcowl.3084= 8/page-2#post-512762

 

- Matt Boiteau

On 2020-01-18 5:29:51 PM, Matt Boitea= u <mattboiteau@gmail.com> wrote:

Have started on the exhaust. Made all three primaries 2" double slip= joints (that alone took almost a whole day with welder). The big can (CA -=  Centrifugal Accumulator) rolled into a 5" can and we'll secure it to = the engine with straps.

The inside pipe is 2.75" which has an area o= f 5.94sq". I'm not sure if there's a magic number, but all the holes I dril= led equaled to just under double the area (11sq"). Most are 3/8, but I did = add some 1/2 to get the total area up. Could we get away with drilling= less holes? Not sure. I'll be able to drill out one side end of the CA and= pull out the inner tube and change out. Will experiment later&nb= sp;with less holes and monitor back pressure. Will weld a npt bung on the C= A and use the wideband bung to measure the different.

The previous e= xhaust with just an Aero Turbine 2525XL, measured ~113dBA. With nothin= g, was closer to 120dBA. Funny around 2000 prop rpm was louder then at 2300= full static. 

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- Matt Boiteau

On 2020-01-07 12:19:23 AM, Matt Boite= au mattboiteau@gmail.com <flyrotary@la= ncaironline.net> wrote:

Okay I'll make all 3 primary tubes (2" diameter) all double slip fit= . Welding batwing tabs (picture below) on to either side on the s= lips, will hold the muffler to the header but allow expansion.

 

Having troubles finding 2.75" bends in 321, so I might have to just = switch to 3" downpipe that is more common. Vband clamp before downpipe for = easier removal and under the plane to allow adding additional exhaust setup= s (long pipe with holes drilled in it, fishmouth tailpipe, etc)


I found a company that makes flex bellows in 321. I'm just not s= ure if I should have it vertical on the downpipe or close to the muffler ho= rizontal before the first 90degree bend downwards.
https://www.= aceraceparts.com/products/3-000-flex-bellow-assembly-321-stainless?variant= =3D11067135556

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Batwing tabs

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- Matt Boiteau

On 2020-01-03 4:22:18 PM, Neil Unger = 12348ung@gmail.com <flyrotary@lancaironlin= e.net> wrote:

Mat,

           &n= bsp;      As usual I have no idea.  I made al= l 3 slip joints and to date no grief in that area.  I am coming around= to the stock manifold in some way.  Yes it is heavy, but appears to m= uffle the noise as well.  Know of 2 installations that use the stock m= anifold with a simple muffler after and both claim "acceptable" noise. It a= ppears that the stock manifold has a big influence on noise??  Would p= refer a DB reading, but if not available it is what it is.  All is com= promise, weight, cost, time, but at the end of the day it has to work. = ;

Still working on the turbo even though the world is on holidays.&nbs= p; All to save my hearing.  So far the rotary is definitely "unique" a= s far as a turbo is concerned.  The heat generated exceeds all else&nb= sp; Two things to date -- special exhaust wheel and water cooled bearing bo= dy =3D, all for heat.  Have modified the stock front plate on the rene= sis to take an electric water pump.  That is the simple bit.

Neil.

On 1/4/2020 5:37 AM, Matt Boiteau mattboiteau@gmail.com<= /a> wrote:

okay I found a good company called SPD Exhaust. They have everything= you need in 321ss.

With the engine being an RX8, we have three exha= ust ports. Should I weld the front and back solid to the muffler, and make = the middle one a slip fit for expansion? Or vice-vesa?

Error= ! Filename not specified.

 

- Matt Boiteau

On 2019-12-28 11:03:42 AM, Finn Lasse= n finn.lassen@verizon.net <flyrotary= @lancaironline.net> wrote:

I did something similar with my RV-3 13B decades ago. It split open = at the welds around one of the pipes from the manifold into the the big out= er tube True, it did use individual manifold base plates, not the connected= factory manifold and the big tube was only 0.035.

Still, I would re= commend slip joints on two of the three pipes, like I added on one of the p= ipes (cut through and a surrounding bigger pipe -- missing in picture).
=
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Can't remember w= hy I went from the above to individual runners into a perforated pipe under= the fuselage. Probably got lured by promise of increased power by tuned le= ngths and still uncomfortable by the muffler being inside the cowling.
<= br>Finn

On 12/28/2019 12:10 AM, Matt Boiteau mattboiteau= @gmail.com wrote:

This is what I'm going to try in a few weeks. 

"Exhaust valve opens and a pulse of hot ga= s puffs out through a short pipe, then ta= ngentially into a cylindrical canister.= Being tangential, the pulse flattens out and travels = helica= lly (rather than bouncing and reverberating around) along the = inside curved wall of the can, spiraling toward the exit, where it comes ou= t more uniform in flow and so pretty quiet."

 

Outer pipe =3D 321 ss 0.050 thick. Flat plate bent to a 5" tube

Inner pipe =3D 321 ss 0.036 thick. 2.5" diameter

(I might use 302ss 0.065 since I already have it)

 

>From my understanding, the area of the holes should be double th= e area of the inner pipe. 

 

- Matt Boiteau

 



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