X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [216.211.128.10] (HELO mail-in04.adhost.com) by logan.com (CommuniGate Pro SMTP 5.1c.5) with ESMTP id 1451843 for flyrotary@lancaironline.net; Mon, 09 Oct 2006 16:04:24 -0400 Received-SPF: none receiver=logan.com; client-ip=216.211.128.10; envelope-from=joeh@pilgrimtech.com Received: from Pilgrim10 (c-67-183-14-47.hsd1.wa.comcast.net [67.183.14.47]) by mail-in04.adhost.com (Postfix) with ESMTP id 9437AB89D6 for ; Mon, 9 Oct 2006 13:06:58 -0700 (PDT) (envelope-from joeh@pilgrimtech.com) From: "Joe Hull" To: "'Rotary motors in aircraft'" Subject: RE: ***SPAM*** [FlyRotary] Re: Exhaust Update Date: Mon, 9 Oct 2006 13:03:29 -0700 Message-ID: <003701c6ebdd$ff005730$bb02a8c0@redmond.corp.microsoft.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0038_01C6EBA3.52A17F30" X-Mailer: Microsoft Office Outlook 11 Thread-Index: Acbr1xRv/Gdd09T9Sg2w1i4bwF9LvwABqr7g X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0038_01C6EBA3.52A17F30 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ah, I hadn=92t thought about that. But I don=92t normally use AvGas. = The only time I have used it was on my attempted trip to OSH. So I have about 10 = hrs on AvGas total. I=92ll keep that in mind during my problem solving = (assuming there is a problem). =20 Thanx, Joe =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson Sent: Monday, October 09, 2006 12:14 PM To: Rotary motors in aircraft Subject: ***SPAM*** [FlyRotary] Re: Exhaust Update =20 Hi Joe, great to hear the improvements. =20 By the way, I can't recall whether you use much 100LL, but if you do and have anything over 10-15 hours on the spark plugs, your EGT drop MIGHT = be sparkplug SAG. If you use only mogas then unlikely. =20 Ed =20 =20 ----- Original Message -----=20 From: Joe Hull =20 To: Rotary motors in aircraft=20 Sent: Monday, October 09, 2006 12:40 PM Subject: [FlyRotary] Exhaust Update =20 Friends and others,=20 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 Nebraska. Once home I began the process of doing a permanent repair of the 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 several = options. =20 In the end I mocked up a design using 1 =BD=94 and 2=94 Sched 40 ABS = plumbing pipe; not quite the exact dimensions for 2=94 and 2.5=94 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 =93ball joints=94 in right after the first bend = about half-way to the merge. Also, the model was designed, and I emphasized = with them over the phone, that each leg was to be pretty close to (exactly?) = 21=94 from the flange to the merge (per Lynn Hanover=92s advice). =20 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=92s a lot of work = and has taken 2 full Saturdays! =20 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 = did a static test and was rewarded with another 200 RPM.=20 =20 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 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=92t know!). = So I created some 11=94 long intake tubes that flare to a =93sort-of=94 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 = 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 everything = 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 Sound and = opened 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 = speed of the prop! So, overall it looks like I have some significant = performance gains!!=20 =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=92s 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=92t 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!! =20 Attached are some pics of the model and the new exhaust. The = =93NewExhaust2=94 picture also shows the new intake in the upper right corner. =20 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 =20 Obviously the Tangential muffler sucks (actually blows) when it comes to performance! WAY too much back pressure. =20 Regards, Joe Hull Cozy Mk-IV N31CZ (65 hrs - Rotary 13B NA)=20 Redmond (Seattle), Washington =20 =20 _____ =20 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_0038_01C6EBA3.52A17F30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ah, I hadn’t thought about = that. But I don’t normally use AvGas.=A0 The only time I have used it was on = my attempted trip to OSH. So I have about 10 hrs on AvGas total. I’ll keep that in mind = during my problem solving (assuming there is a = problem).

 

Thanx,

Joe

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson
Sent: Monday, October 09, = 2006 12:14 PM
To: Rotary motors in aircraft
Subject: ***SPAM*** = [FlyRotary] Re: Exhaust Update

 

Hi Joe, great to hear the = improvements.

 

By the way, I can't recall whether you use much = 100LL, but if you do and have anything over 10-15 hours on the spark plugs, your = EGT drop MIGHT be sparkplug SAG.  If you use only mogas then = unlikely.

 

Ed

 

 

----- Original Message ----- =

From: Joe = Hull

Sent: Monday, = October 09, 2006 12:40 PM

Subject: = [FlyRotary] Exhaust Update

 

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 Nebraska. Once home I began the process of doing a permanent repair of the 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 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– 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 with them over the phone, that = each leg was to be pretty close to (exactly?) 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 = shield 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 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 did a static test and was rewarded with another 200 RPM. =

 

Oh, let me backup a minute. While the engine was down – waiting for the new exhaust I decided to re-do my intake = manifold. I have the short Atkins manifold and had a plenum attached directly to the = TWM throttle body – 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 the air – up to 5400RPM and = another 3-5kts airspeed (162kts). So that was a win. =

 

OK, back to the new exhaust – I was not getting 4400-4500 RPM static and after running for 20 minutes or so and checking = to make sure everything was still secure – I decided to take to the = skies before it got totally dark. There was a very noticeable improvement in = takeoff and climb – VERY NOTICEABLE.  So I headed out west of the = airport over Puget Sound and opened 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 speed of the prop! So, = overall it looks like I have some significant performance gains!! =

 

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 – 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 – 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:

         =             &= nbsp;  Static RPM     Flying = RPM      Max Speed

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

New Intake        =   4250           &nb= sp;     5400           &nb= sp;   162kts TAS

New Exhaust       4500           &nb= sp;     5950           &nb= sp;   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/

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