X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wx-out-0506.google.com ([66.249.82.225] verified) by logan.com (CommuniGate Pro SMTP 5.1c.5) with ESMTP id 1451467 for flyrotary@lancaironline.net; Mon, 09 Oct 2006 13:06:48 -0400 Received-SPF: pass receiver=logan.com; client-ip=66.249.82.225; envelope-from=wdleonard@gmail.com Received: by wx-out-0506.google.com with SMTP id i29so1641908wxd for ; Mon, 09 Oct 2006 10:06:28 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=gx7Ens+O381hIxYEqPXYs3S0UkRB3cKWm0cI+V+xceOb7IZ3XhQ+hOgKS+fyNnEL3ItyBLsoEpEuvcI+kwQlXRDS41bUk7KNFK2L5Tk/w5iBgE+fjCdFRFXcz8HAINYXL/sSOJWTXNOanEH+mhJMjPQ8cHWfCCRClpSxtKoYDgw= Received: by 10.90.28.12 with SMTP id b12mr2869291agb; Mon, 09 Oct 2006 10:06:27 -0700 (PDT) Received: by 10.90.94.10 with HTTP; Mon, 9 Oct 2006 10:06:27 -0700 (PDT) Message-ID: <1c23473f0610091006i3335fbber594a29b579289fb8@mail.gmail.com> Date: Mon, 9 Oct 2006 10:06:27 -0700 From: "David Leonard" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Exhaust Update In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_214026_14469333.1160413587888" References: ------=_Part_214026_14469333.1160413587888 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Well done Joe!!! That kind of story almost makes me want to drop the turbo for a NA installation. Dave Leonard On 10/9/06, Joe Hull wrote: > > Friends and others, > > As you may recall, on the way to Osh on July 23 my exhaust system decided > to depart the engine leaving a lot of melted wires and charred cowling. I > got it tacked back together and raced home to Seattle from western Nebras= ka. > Once home I began the process of doing a permanent repair of the wires an= d > developing a new exhaust system. The wires were the easy part. The exhaus= t > system has been a long arduous process in which I pursued several options= . > > > > In the end I mocked up a design using 1 =BD" and 2" Sched 40 ABS plumbing > pipe; not quite the exact dimensions for 2" and 2.5" ID x .049 stainless= =96 > but close enough. I sent the model off to Aircraft Exhaust in Princeton, > Minnesota and a mere 4-5 weeks later I got my finished exhaust system. I = had > them put a couple of "ball joints" in right after the first bend about > half-way to the merge. Also, the model was designed, and I emphasized wit= h > them over the phone, that each leg was to be pretty close to (exactly?) 2= 1" > from the flange to the merge (per Lynn Hanover's advice). > > > > I received the exhaust 2 weeks ago. Getting it on the plane was a breeze. > Unfortunately designing and fabricating a support system for it, so it is > firmly braced to the engine, and fabricating a stainless heat shield took= 24 > or more hours! Since the airport is 50 miles away that's a lot of work an= d > has taken 2 full Saturdays! > > > > Anyway, my efforts were rewarded late Saturday when I finally got it all > together and began testing. I ran the engine on the ground at low RPM > (1200-2000) while the oil warmed up. After the oil was above 120 deg. I d= id > a static test and was rewarded with another 200 RPM. > > > > Oh, let me backup a minute. While the engine was down =96 waiting for the > new exhaust I decided to re-do my intake manifold. I have the short Atkin= s > manifold and had a plenum attached directly to the TWM throttle body =96 = with > nice sharp edges butting up to the throttle body (hey I didn't know!). So= I > created some 11" long intake tubes that flare to a "sort-of" bell mouth > inside my air-cleaner plenum. I tested that briefly with the old muffler = and > on the ground got another 100-150 RPM static and another 200-300 RPM in t= he > air =96 up to 5400RPM and another 3-5kts airspeed (162kts). So that was a= win. > > > > > OK, back to the new exhaust =96 I was not getting 4400-4500 RPM static an= d > after running for 20 minutes or so and checking to make sure everything w= as > still secure =96 I decided to take to the skies before it got totally dar= k. > There was a very noticeable improvement in takeoff and climb =96 VERY > NOTICEABLE. So I headed out west of the airport over Puget Sound and ope= ned > it up to see what would happen. It shot past 162kts and settled in around > 179kts and about 5950 RPM!! Which is also pretty close to the design spee= d > of the prop! So, overall it looks like I have some significant performanc= e > gains!! > > > > Around the end of the flight (or actually the cause of the end), I though= t > I felt a little change in vibration and it looked like the EGT's went dow= n =96 > so I hightailed it back to the airport at reduced power (of course > descending even at reduced power meant I was still moving at 200MPH) and = had > an uneventful landing and taxi back to the hangar. I didn't have time to > pull the cowls =96 but everything I could see from the outside looked OK.= So, > I have to see whether the problem was in my head or in the engine!! > > > > Attached are some pics of the model and the new exhaust. The "NewExhaust2= " > picture also shows the new intake in the upper right corner. > > > > Performance Re-cap: > > Static RPM Flying RPM Max Speed > > Original 4100 5150(max) 157kts TAS > > New Intake 4250 5400 162kts TAS > > New Exhaust 4500 5950 179kts TAS > > > > Obviously the Tangential muffler sucks (actually blows) when it comes to > performance! WAY too much back pressure. > > > > Regards, > > Joe Hull > > Cozy Mk-IV N31CZ (65 hrs - Rotary 13B NA) > > Redmond (Seattle), Washington > > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > > > > --=20 David Leonard Turbo Rotary RV-6 N4VY My websites at: http://members.aol.com/_ht_a/rotaryroster/index.html http://members.aol.com/_ht_a/vp4skydoc/index.html http://leonardiniraq.blogspot.com ------=_Part_214026_14469333.1160413587888 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
Well done Joe!!!  That kind of story almost makes me want to drop= the turbo for a NA installation. 
 
Dave Leonard

 
On 10/9/06, = Joe Hull <joeh@pilgrimtech.c= om> wrote:

Friends and others,

As you may recall, on the way to Osh on July 23 my exhaust syst= em decided to depart the engine leaving a lot of melted wires and charred c= owling. I got it tacked back together and raced home to Seattle from wester= n Nebraska. Once home I began the process of doing a permanent repair of th= e wires and developing a new exhaust system. The wires were the easy part. = The exhaust system has been a long arduous process in which I pursued sever= al options.

 

In the end I mocked up a design using 1 =BD" and 2" Sched 40 AB= S plumbing pipe; not quite the exact dimensions for 2" and 2.5" ID x .049 s= tainless=96 but close enough. I sent the model off to Aircraft Exhaust in P= rinceton, Minnesota and a mere 4-5 weeks later I got my finished exhaust sy= stem. I had them put a couple of "ball joints" in right after the first ben= d about half-way to the merge. Also, the model was designed, and I emphasiz= ed with them over the phone, that each leg was to be pretty close to (exact= ly?) 21" from the flange to the merge (per Lynn Hanover's advice).

 

I received the exhaust 2 weeks ago. Getting it on the plane was= a breeze. Unfortunately designing and fabricating a support system for it,= so it is firmly braced to the engine, and fabricating a stainless heat shi= eld took 24 or more hours! Since the airport is 50 miles away that's a lot = of work and has taken 2 full Saturdays!

 

Anyway, my efforts were rewarded late Saturday when I finally g= ot it all together and began testing. I ran the engine on the ground at low= RPM (1200-2000) while the oil warmed up. After the oil was above 120 deg. = I did a static test and was rewarded with another 200 RPM.=20

 

Oh, let me backup a minute. While the engine was down =96 waiti= ng for the new exhaust I decided to re-do my intake manifold. I have the sh= ort Atkins manifold and had a plenum attached directly to the TWM throttle = body =96 with nice sharp edges butting up to the throttle body (hey I didn'= t know!). So I created some 11" long intake tubes that flare to a "sort-of"= bell mouth inside my air-cleaner plenum. I tested that briefly with the ol= d muffler and on the ground got another 100-150 RPM static and another 200-= 300 RPM in the air =96 up to 5400RPM and another 3-5kts airspeed (162kts). = So that was a win.=20

 

OK, back to the new exhaust =96 I was not getting 4400-4500 RPM= static and after running for 20 minutes or so and checking to make sure ev= erything was still secure =96 I decided to take to the skies before it got = totally dark. There was a very noticeable improvement in takeoff and climb = =96 VERY NOTICEABLE.  So I headed out west of the airport over Puget S= ound and opened it up to see what would happen. It shot past 162kts and set= tled in around 179kts and about 5950 RPM!! Which is also pretty close to th= e design speed of the prop! So, overall it looks like I have some significa= nt performance gains!!=20

 

Around the end of the flight (or actually the cause of the end)= , I thought I felt a little change in vibration and it looked like the EGT'= s went down =96 so I hightailed it back to the airport at reduced power (of= course descending even at reduced power meant I was still moving at 200MPH= ) and had an uneventful landing and taxi back to the hangar. I didn't have = time to pull the cowls =96 but everything I could see from the outside look= ed OK. So, I have to see whether the problem was in my head or in the engin= e!!

 

Attached are some pics of the model and the new exhaust. The "N= ewExhaust2" picture also shows the new intake in the upper right corner.

 

Performance Re-cap:

          &nb= sp;            = Static RPM     Flying RPM     = ; Max Speed

Original         &= nbsp;     4100       = ;          5150(max) &nbs= p;     157kts TAS

New Intake          425= 0            &n= bsp;    5400        =        162kts TAS

New Exhaust       4500  = ;            &n= bsp;  5950          =      179kts TAS

 

Obviously the Tangential muffler sucks (actually blows) when it= comes to performance! WAY too much back pressure.

 

Regards,

 

 


--
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=
--
David Leonard

Turbo Rotary RV-6 N4VY
My websites at:http://m= embers.aol.com/_ht_a/rotaryroster/index.html
http:= //members.aol.com/_ht_a/vp4skydoc/index.html
http://leonardiniraq.blogspot.com=20 ------=_Part_214026_14469333.1160413587888--