X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from smtp109.sbc.mail.re2.yahoo.com ([68.142.229.96] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with SMTP id 1876714 for flyrotary@lancaironline.net; Thu, 01 Mar 2007 13:25:33 -0500 Received-SPF: none receiver=logan.com; client-ip=68.142.229.96; envelope-from=downing.j@sbcglobal.net Received: (qmail 68623 invoked from network); 1 Mar 2007 18:24:45 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Received:X-YMail-OSG:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=mK88Y0Thp0yHRClLuZJmKikVp1P8N1TNSQ+kresZG52CJgB2Xy3R7GU9KVBFGSwAgKry9a/fvYWqy4dYpbH6RUnj1skJ9QZrtFro4pg0YDCAWyutuvWdKTztifYXv/tBVIX+Xye9OAvY8jL8xVuIvEmpfOTmMRPnI7wdWEOhiOA= ; Received: from unknown (HELO mom) (downing.j@sbcglobal.net@75.40.224.46 with login) by smtp109.sbc.mail.re2.yahoo.com with SMTP; 1 Mar 2007 18:24:45 -0000 X-YMail-OSG: TUImLuoVM1l8opeghR28YeSM6lmdEb_QRQcTrWCkVzjnzY8qhXu4hRI7XejAZyzxnXICtxhqHSasuBo_raBNtTLjk82IhXN_J5h8xxgndFmWo5c_K3qWqLFpcLp_bdm5Qxs9bSxc5J7_JUr64Y1VZCymCQ-- Message-ID: <001101c75c2e$f2943a40$4001a8c0@gateway.2wire.net> From: "John Downing" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: diffusers Date: Thu, 1 Mar 2007 13:25:10 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000E_01C75C05.09597D00" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_000E_01C75C05.09597D00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, I like that fist theory, it eliminates all the cameras, yarn and = other things that maybe you don't care to analyze. Thanks JohnD ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Thursday, March 01, 2007 9:53 AM Subject: [FlyRotary] Re: diffusers John, I would go with the 22 1/4 sq inches. For these reasons: 1. Your engine may produce more power than the one I run with - = requiring more heat rejection. 2. It is easier to neck down the opening (than widen it) if it turns = out you have more than what is necessary - or do nothing 3. My cowl exit area is probably a bit larger than most which may = produce less back pressure enabling smaller opening to flow more air. Ball up your fist and see if you can stick it through the narrowest = opening - it should just almost go (that is if you have the same size = hands I do {:>)) How's that for a standard of measure? Ed ----- Original Message -----=20 From: John Downing=20 To: Rotary motors in aircraft=20 Sent: Thursday, March 01, 2007 9:39 AM Subject: [FlyRotary] diffusers Ed, If I add the extension, indicated with cardboard w/lines, I = have the original 22 1/4 sq. in's. If I block off the cowl openings to = match the diffuser, I will have 18 7/8 sq. inches. The neck at the = smallest point is approximately 15 sq. inches as close as I can = determine by my barn door math. Which is the better way to go, opening = wise, the larger or the smaller opening. If these numbers are in the = ball park, I'll lay up the glass. Thankyou JohnD -------------------------------------------------------------------------= --- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_000E_01C75C05.09597D00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ed, I like that fist theory, it = eliminates=20 all the cameras, yarn and other things that maybe you don't care to=20 analyze. Thanks JohnD

----- Original Message -----
From:=20 Ed=20 Anderson
To: Rotary motors in = aircraft

Sent: Thursday, March 01, 2007 = 9:53=20 AM

Subject: [FlyRotary] Re: = diffusers

John, I would go with the 22 1/4 sq = inches. For=20 these reasons:

1. Your engine may produce more power = than the one=20 I run with - requiring more heat rejection.

2. It is easier to neck down the opening = (than=20 widen it) if it turns out you have more than what is necessary - = or do=20 nothing

3. My cowl exit area is probably a bit = larger than=20 most which may produce less back pressure enabling smaller opening to = flow=20 more air.

Ball up your fist and see if you can stick it = through=20 the narrowest opening - it should just almost go (that is if you have = the same=20 size hands I do {:>)) How's that for a standard of=20 measure?

Ed

----- Original Message -----
From:=20 John=20 Downing
To: Rotary motors in = aircraft=20

Sent: Thursday, March 01, = 2007 9:39=20 AM

Subject: [FlyRotary] = diffusers

Ed, If I add the extension, = indicated=20 with cardboard w/lines, I have the original 22 1/4 sq. in's. = If I=20 block off the cowl openings to match the diffuser, I will have 18 = 7/8 sq.=20 inches. The neck at the smallest point is approximately 15 sq. = inches=20 as close as I can determine by my barn door math. Which is the = better=20 way to go, opening wise, the larger or the smaller opening. If = these=20 numbers are in the ball park, I'll lay up the glass. = Thankyou =20 JohnD

--
Homepage: http://www.flyrotary.com/
Archive = and=20 UnSub: =20 = http://mail.lancaironline.net/lists/flyrotary/

------=_NextPart_000_000E_01C75C05.09597D00--