X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103] verified) by logan.com (CommuniGate Pro SMTP 5.1c.5) with ESMTP id 1451730 for flyrotary@lancaironline.net; Mon, 09 Oct 2006 15:13:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-101-137.carolina.res.rr.com [24.74.101.137]) by ms-smtp-04.southeast.rr.com (8.13.6/8.13.6) with SMTP id k99JDa8m023641 for ; Mon, 9 Oct 2006 15:13:37 -0400 (EDT) Message-ID: <002401c6ebd7$10b85650$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Exhaust Update Date: Mon, 9 Oct 2006 15:13:55 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0021_01C6EBB5.894E8430" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0021_01C6EBB5.894E8430 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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 -----=20 From: Joe Hull=20 To: Rotary motors in aircraft=20 Sent: Monday, October 09, 2006 12:40 PM Subject: [FlyRotary] Exhaust Update 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" 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). =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's = 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 - 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.=20 =20 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!!=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'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!! =20 Attached are some pics of the model and the new exhaust. The = "NewExhaust2" 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 -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_0021_01C6EBB5.894E8430 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Joe, great to hear the = improvements.
 
By the way, I can't recall whether you use much = 100LL, but=20 if you do and have anything over 10-15 hours on the spark plugs, your = EGT drop=20 MIGHT be sparkplug SAG.  If you use only mogas then = unlikely.
 
Ed
 
 
----- Original Message -----
From:=20 Joe Hull=20
Sent: Monday, October 09, 2006 = 12:40=20 PM
Subject: [FlyRotary] Exhaust = Update

Friends and others,=20

As you may recall, on = the way to=20 Osh on July 23=20 my exhaust system decided to depart the engine leaving a lot of melted = wires=20 and charred cowling. I got it tacked back together and raced home to = Seattle from western Nebraska. Once home I began the = process of=20 doing a permanent repair of the wires and developing a new exhaust = system. The=20 wires were the easy part. The exhaust system has been a long arduous = process=20 in which I pursued several options.

 

In the end I mocked up a = design=20 using 1 =BD=94 and 2=94 Sched 40 ABS plumbing pipe; not quite the = exact dimensions=20 for 2=94 and 2.5=94 ID x .049 stainless=96 but close enough. I sent = the model off to=20 Aircraft Exhaust in Princeton, Minnesota and a mere 4-5 weeks = later I got=20 my finished exhaust system. I had them put a couple of =93ball = joints=94 in right=20 after the first bend about half-way to the merge. Also, the model was=20 designed, and I emphasized with them over the phone, that each leg was = to be=20 pretty close to (exactly?) 21=94 from the flange to the merge (per = Lynn=20 Hanover=92s advice).

 

I received the exhaust 2 = weeks=20 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=20 fabricating a stainless heat shield took 24 or more hours! Since the = airport=20 is 50 miles away that=92s a lot of work and has taken 2 full=20 Saturdays!

 

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

 

Oh, let me backup a = minute. While=20 the engine was down =96 waiting for the new exhaust I decided to re-do = my intake=20 manifold. I have the short Atkins manifold and had a plenum attached = directly=20 to the TWM throttle body =96 with nice sharp edges butting up to the = throttle=20 body (hey I didn=92t know!). So I created some 11=94 long intake tubes = that flare=20 to a =93sort-of=94 bell mouth inside my air-cleaner plenum. I tested = that briefly=20 with the old muffler and on the ground got another 100-150 RPM static = and=20 another 200-300 RPM in the air =96 up to 5400RPM and another 3-5kts = airspeed=20 (162kts). So that was a win.

 

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

 

Around the end of the = flight (or=20 actually the cause of the end), I thought I felt a little change in = vibration=20 and it looked like the EGT=92s went down =96 so I hightailed it back = to the=20 airport at reduced power (of course descending even at reduced power = meant I=20 was still moving at 200MPH) and had an uneventful landing and taxi = back to the=20 hangar. I didn=92t have time to pull the cowls =96 but everything I = could see from=20 the outside looked OK. So, I have to see whether the problem was in my = head or=20 in the engine!!

 

Attached are some pics = of the=20 model and the new exhaust. The =93NewExhaust2=94 picture also shows = the new intake=20 in the upper right corner.

 

Performance=20 Re-cap:

           =              = Static RPM     Flying = RPM     =20 Max Speed

Original         &nbs= p;    =20 = 4100           &nb= sp;   =20  5150(max)       157kts=20 TAS

New=20 Intake         =20 = 4250           &nb= sp;    =20 = 5400           &nb= sp;  =20 162kts TAS

New=20 Exhaust      =20 = 4500           &nb= sp;    =20 = 5950           &nb= sp;  =20 179kts TAS

 

Obviously the Tangential = muffler=20 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)=20

Redmond (Seattle),=20 Washington

 

 

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