X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao105.cox.net ([68.230.241.41] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3410168 for flyrotary@lancaironline.net; Sun, 04 Jan 2009 11:16:32 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.41; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao105.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090104161550.HDQJ8485.fed1rmmtao105.cox.net@fed1rmimpo02.cox.net> for ; Sun, 4 Jan 2009 11:15:50 -0500 Received: from BigAl ([72.192.137.74]) by fed1rmimpo02.cox.net with bizsmtp id zUFp1a00L1cVYgg04UFpz2; Sun, 04 Jan 2009 11:15:49 -0500 X-Authority-Analysis: v=1.0 c=1 a=NSHW2kUv_6QA:10 a=Zgn9d7bnwx8A:10 a=kviXuzpPAAAA:8 a=W3JjxVAS_7ZMMM_bldYA:9 a=wcpREg0h4Eu9EWKNaiMA:7 a=iEuIBoPH5tI8ht3A2wccYflonGwA:4 a=4vB-4DCPJfMA:10 a=gx5bkW9XiUAA:10 a=_kBf8icFwsaBHI-JjCYA:9 a=8S6-t2xn-yIgcTHuiTcA:7 a=veXfjAiqpkSBTRbd128eVMDx1O8A:4 a=37WNUvjkh6kA:10 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: 20B install issues overcome Date: Sun, 4 Jan 2009 08:17:09 -0800 Message-ID: <294300CF176944C4AD0A53F4553969F0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C96E44.D6E6EF20" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C96E44.D6E6EF20 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Subject: [FlyRotary] Re: 20B install issues overcome =20 My exhaust exits about 6-7 inches from prop and goes through near the = root of the blades (pusher). It occurs to me that having my exhaust exit = through the prop may help reduce or mask the exhaust noise. On a takeoff roll = there is a prop blade breaking that exhaust stream about 130 times per second. Let's see, that's about 1 blade passing for every two exhaust pulses on = the 20B - could make a difference. =20 The secondary muffler/resonator I have also helps. On the dyno we = measured that resulted in about 6 db reduction. =20 Al G Agree. Unfortunately, that's not a comment I hear. On the contrary, = they usually tell me that they can hear me before they can see me. ;-( =20 Mark S. ANR headsets mandatory On Sun, Jan 4, 2009 at 12:22 AM, Al Gietzen wrote: I'm presently gathering materials to fabricate a tangential muffler made from inconel, similar to your design. I take it from your report that = your muffler is holding up well? =20 Mark S. =20 So far it is doing fine. And the inconel tangential and the 321SS = secondary muffler (my own design) quiet it down nicely. A few days ago I picked = up my brother to go for a ride, while my sister-in-law waited and watched = other planes come and go. When we got back her remark was that my plane was quieter than all the rest. I consider that to be 'expert testimony':-). Al G On Sat, Jan 3, 2009 at 5:47 PM, Al Gietzen wrote: Al,=20 That's a great shot. Have you had any "significant issues" with your install? If so, how did you overcome them? Mark S. =20 I had 2 issues that required some time and determination. The first was = the RWS EC2. I had an early version for the 3-rotor, and perhaps the first installed in a composite airplane. I had some kind of electrical noise related corruption of settings which persisted through a lot of effort = for over a years time. It has been resolved, and the engine running fine. = That has been discussed here more than once in the past. The other was less-than-expected performance of an oil cooler built into = the wing root, without much of a scoop for the inlet below the wing. The = theory was that the differential pressure below/above the wing would help = provide the necessary air flow. Not the case here as the location is too far = back on the wing; and behind the strake (the inboard section on the canard airplane). The pressure differential turned out to be only about 1" H20 = - very little help. I added a ram scoop, and installed a small oil/water = heat exchanger in the cowl. Currently oil temps are fine, and the coolant = temp is running a bit lower than I like at cruise. I may eventually install = some sort of air flow adjustment, or even consider installing a thermostat in = the engine. You may recall discussion of these changes here in the past as well. I'm just past 140 hours flying time, and feel quite fortunate with how = well things have worked out. Performance and economy are great. Al G http://members.cox.net/alg3/airplane.htm =20 =20 =20 =20 ------=_NextPart_000_0010_01C96E44.D6E6EF20 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Subject: [FlyRotary] Re: 20B install issues overcome

 

My exhaust exits about 6-7 inches = from prop and goes through near the root of the blades (pusher). It occurs to = me that having my exhaust exit through the prop may help reduce or mask the exhaust noise.  On a takeoff roll there is a prop blade breaking = that exhaust stream about 130 times per second. Let’s see, that’s = about 1 blade passing for every two exhaust pulses on the 20B – could = make a difference.

 

The secondary muffler/resonator I = have also helps.  On the dyno we measured that resulted in about 6 db = reduction.

 

Al G

Agree.  Unfortunately, that's not a comment I hear.  On the contrary, they = usually tell me that they can hear me before they can see me.  ;-(  =

Mark S.
ANR headsets mandatory

On Sun, Jan 4, 2009 at 12:22 = AM, Al Gietzen <ALVentures@cox.net> wrote:

I'm = presently gathering materials to fabricate a tangential muffler made from inconel, similar to your design.  I take it from your report that your = muffler is holding up well?        

Mark S.

 

So far it is doing fine.  And the inconel tangential = and the 321SS secondary muffler (my own design) quiet it down nicely.  A = few days ago I picked up my brother to go for a ride, while my sister-in-law = waited and watched other planes come and go.  When we got back her remark was = that my plane was quieter than all the rest.  I consider that to be 'expert testimony'J.

Al G

On Sat, Jan 3, 2009 at 5:47 PM, = Al Gietzen <ALVentures@cox.net> wrote:

Al, =

That's a great shot.  Have you had any "significant = issues" with your install?  If so, how did you overcome them?
Mark S. 

I had 2 issues that required some time and determination. = The first was the RWS EC2.  I had an early version for the 3-rotor, and = perhaps the first installed in a composite airplane.  I had some kind of = electrical noise related corruption of settings which persisted through a lot of = effort for over a years time. It has been resolved, and the engine running = fine.  That has been discussed here more than once in the = past.

The other was less-than-expected performance of an oil = cooler built into the wing root, without much of a scoop for the inlet below the = wing.  The theory was that the differential pressure below/above the wing = would help provide the necessary air flow.  Not the case here as the location = is too far back on the wing; and behind the strake (the inboard section on the = canard airplane).  The pressure differential turned out to be only about = 1" H20 – very little help.  I added a ram scoop, and installed a = small oil/water heat exchanger in the cowl.  Currently oil temps are = fine, and the coolant temp is running a bit lower than I like at cruise.  I = may eventually install some sort of air flow adjustment, or even consider = installing a thermostat in the engine.  You may recall discussion of these = changes here in the past as well.

I'm just past 140 hours flying time, and feel quite = fortunate with how well things have worked out.  Performance and economy are = great.

Al G   http://members.cox.net/alg3/airplane.htm

 

 

 

 

------=_NextPart_000_0010_01C96E44.D6E6EF20--