X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail05.syd.optusnet.com.au ([211.29.132.186] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTPS id 3412492 for flyrotary@lancaironline.net; Tue, 06 Jan 2009 02:55:03 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.186; envelope-from=lendich@optusnet.com.au Received: from george (d58-109-48-212.dsl.nsw.optusnet.com.au [58.109.48.212]) by mail05.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id n067sJDN018854 for ; Tue, 6 Jan 2009 18:54:20 +1100 Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: 20B install issues overcome Date: Tue, 6 Jan 2009 17:54:23 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000D_01C97027.CF1BA260" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 090105-0, 05/01/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_000D_01C97027.CF1BA260 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks again Bill, I tend to agree. George (down under) ----- Original Message -----=20 From: wrjjrs@aol.com=20 To: Rotary motors in aircraft=20 Sent: Tuesday, January 06, 2009 8:07 AM Subject: [FlyRotary] Re: 20B install issues overcome George, That might have been a problem with the old carburettor fed rotarys, = and in fact they ran a thermal reactor on the early ones. With modern = EFI and even lean of peak operation and closed loop O2 sensor operation = that shouldn't be a problem. When the O2 sensor is used the idea is to = be SURE there isn't any O2 left, but more important that there isn't any = FUEL left. The O2 sensor is really an unburned fuel sensor that just = works backwards since it is easier to sense oxygen than any of the other = exhaust gasses. Without fuel to ignite what is going to burn? Bill Jepson -----Original Message----- From: George Lendich To: Rotary motors in aircraft Sent: Mon, 5 Jan 2009 1:09 pm Subject: [FlyRotary] Re: 20B install issues overcome Bill, I had a talk with Mistral a while back and the chief engineer had some = concerns with introducing fresh air into the exhaust ( for cooling) as = it might initiate burning of residual fuel - hence more heat rather than = less heat. That's why their cool tube (over the exhaust tube) is discharged = separate to the exhaust. Although I intend to proceed with out original design just to see the = results. Do you have any comments on this ? George (down under) Earnest, I believe that the SuperTrapp muffler is an example of a band gap = device and it worked well, if properly tuned. I think the large block idea has merit too, but you will have to = allow enough thickness to prevent the tubes that see the exhaust first = to fight the harmonic vibration and heat. Different size diamonds in the = exhaust stream might also help fight harmonics. Bill Jepson -------------------------------------------------------------------------= --- Get a free MP3 every day with the Spinner.com Toolbar. Get it Now.=20 -------------------------------------------------------------------------= ----- Get a free MP3 every day with the Spinner.com Toolbar. Get it Now. ------=_NextPart_000_000D_01C97027.CF1BA260 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks again Bill,
I tend to agree.
George (down under)
----- Original Message -----
From:=20 wrjjrs@aol.com
Sent: Tuesday, January 06, 2009 = 8:07=20 AM
Subject: [FlyRotary] Re: 20B = install=20 issues overcome

George,
That might have been a problem with the old=20 carburettor fed rotarys, and in fact they ran a thermal reactor on the = early=20 ones. With modern EFI and even lean of peak operation and closed = loop O2=20 sensor operation that shouldn't be a problem. When the O2 sensor = is used=20 the idea is to be SURE there isn't any O2 left, but more important = that there=20 isn't any FUEL left. The O2 sensor is really an unburned fuel sensor = that just=20 works backwards since it is easier to sense oxygen than any of the = other=20 exhaust gasses. Without fuel to ignite what is going to burn?
Bill=20 Jepson


-----Original Message-----
From: George Lendich=20 <lendich@optusnet.com.au>
To: Rotary motors in aircraft=20 <flyrotary@lancaironline.net>
Sent: Mon, 5 Jan 2009 1:09=20 pm
Subject: [FlyRotary] Re: 20B install issues overcome

Bill,
I had a talk with Mistral a while = back and the=20 chief engineer had some concerns with introducing fresh air into the = exhaust (=20 for cooling) as it might initiate burning of residual fuel - hence = more heat=20 rather than less heat.
That's why their cool tube (over the = exhaust=20 tube) is discharged separate to the exhaust.
Although I intend to proceed with out = original=20 design just to see the results.
Do you have any comments on this = ?
George (down under)
Earnest,
I=20 believe that the SuperTrapp muffler is an example of a band gap = device and=20 it worked well, if properly tuned.
I think the large block idea = has merit=20 too, but you will have to allow enough thickness to prevent the = tubes that=20 see the exhaust first to fight the harmonic vibration and heat. = Different=20 size diamonds in the exhaust stream might also help fight = harmonics.
Bill=20 Jepson


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