X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from ms-smtp-05.southeast.rr.com ([24.25.9.104] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 2027536 for flyrotary@lancaironline.net; Sat, 05 May 2007 14:12:42 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.104; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-05.southeast.rr.com (8.13.6/8.13.6) with SMTP id l45IBgrV024011 for ; Sat, 5 May 2007 14:11:43 -0400 (EDT) Message-ID: <000901c78f41$05ed4330$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Was it Something I said? Date: Sat, 5 May 2007 14:13:03 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01C78F1F.7E812720" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0006_01C78F1F.7E812720 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable No, but I thought of something else.=20 The larger the TB, the greater the cross section per degree of shaft = rotation. So if all is equal save diameter, the stumble from over-lean = surge will always be greater from the larger TB. It will open to a = larger cross section than any smaller TB in a smaller movement of the = throttle. Conversely, the smaller TB amounts to opening the throttle = more slowly for a similar amount of throttle movement. And since slower = movement of the throttle is one strategy for avoiding the stumble = problem, the smaller TB is already doing that without any thought from = the pilot. The same thinking for the progressive 4 barrel carb. Two = small holes to start, and as flow increases, two larger holes to get to = top power. Lynn E. Hanover Ah! Certainly makes sense to me. I just knew that whenever I put on = the Monster TB the engine would hesitate upon rapid open of throttle = whereas it did not with the smaller TB. Lynn, You need to compile all = this insight to throttle bodies pros/cons including the material you = presented regarding runner TB interaction. Marv, could post it to the = Fly Rotary website. Ed -------------------------------------------------------------------------= ----- See what's free at AOL.com. ------=_NextPart_000_0006_01C78F1F.7E812720 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 No, but I thought of something else.
 
The larger the TB, the greater the cross section per degree of = shaft=20 rotation. So if all is equal save diameter, the stumble from over-lean = surge=20 will always be greater from the larger TB. It will open to a larger = cross=20 section than any smaller TB in a smaller movement of the = throttle.=20 Conversely, the smaller TB amounts to opening the throttle more slowly = for a=20 similar amount of throttle movement. And since slower movement of the = throttle=20 is one strategy for avoiding the stumble problem, the smaller TB is = already=20 doing that without any thought from the pilot. The same thinking for = the=20 progressive 4 barrel carb. Two small holes to start, and as flow = increases,=20 two larger holes to get to top power.
 
Lynn E. Hanover

 
Ah!  Certainly makes sense to me.  I just knew that = whenever I=20 put on the Monster TB the engine would hesitate upon rapid open of = throttle=20 whereas it did not with the smaller TB.  Lynn,  You need to = compile=20 all this insight to throttle bodies pros/cons including the material = you=20 presented regarding runner TB interaction.  Marv, could post it = to the=20 Fly Rotary website.
 
Ed

See what's free at AOL.com.=20
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