Return-Path: <13brv3@bellsouth.net> Received: from imf17aec.mail.bellsouth.net ([205.152.59.65] verified) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP id 100190 for flyrotary@lancaironline.net; Tue, 01 Jun 2004 22:26:00 -0400 Received: from rad ([65.6.194.9]) by imf17aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040602022529.FXIP13581.imf17aec.mail.bellsouth.net@rad> for ; Tue, 1 Jun 2004 22:25:29 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Rev-2.1 part 2 Date: Tue, 1 Jun 2004 21:23:33 -0500 Message-ID: <016301c44848$9a2e5770$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0164_01C4481E.B1584F70" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0164_01C4481E.B1584F70 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Do you think 48-50mm's would boost power? Mo mix? The allout Racing = Beat wrap around intake uses 48MM Webers or Dellorto carbs. Dave Atkins is really estute with that rig, so what does he say? TJ=20 =20 One simple theory says that the largest throat possible will decrease = air flow resistance, and let the MAP get closer to the actual ambient = pressure. This ignores the more complicated theory that says that higher velocity = air through a smaller opening will help stuff more air in the chamber. Everything is a compromise, so your best results will be somewhere in between tiny, and huge. Ed will calculate this for you, since he has no flying plane :-) =20 Seriously, my 40 mm (which I didn't chose) has the same ID as the 1.75" = OD tubing that I used for runners. I doubt they're causing me any problems now, but I do worry that it will be somewhat restrictive when I get to = the -C drive, and 7000+ rpm. If I end up matching Tracy's static rpm with = this setup, it will be interesting to see how I do with the higher rpm configuration. =20 =20 If you want to know what Dave has to say, give him a call. I've had my = last conversation with him. =20 =20 Cheers, Rusty (low tolerance for BS) ------=_NextPart_000_0164_01C4481E.B1584F70 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Do you = think=20 48-50mm's would boost power?  Mo mix?  The allout Racing  = Beat=20 wrap around intake uses 48MM Webers or Dellorto carbs.  Dave = Atkins is=20 really estute with that rig, so what does he say?
TJ 
 
One = simple theory says=20 that the largest throat possible will decrease air=20 flow resistance, and let the MAP get closer to the actual ambient=20 pressure.  This ignores the more complicated theory that says that = higher=20 velocity air through a smaller opening will help stuff more air in=20 the chamber.   Everything is a compromise, so your = best=20 results will be somewhere in between tiny, and huge.  Ed will = calculate=20 this for you, since he has no flying plane=20 :-)
 
Seriously, my 40 mm=20 (which I didn't chose) has the same ID as the 1.75" OD tubing that = I used=20 for runners.  I doubt they're causing me any problems now, but I do = worry=20 that it will be somewhat restrictive when I get to the -C drive, and = 7000+=20 rpm.   If I end up matching Tracy's static rpm with this=20 setup, it will be interesting to see how I do with the higher=20 rpm configuration.  
 
If you want to = know what=20 Dave has to say, give him a call.  I've had my last = conversation with=20 him. 
 
Cheers,
Rusty (low = tolerance for=20 BS)
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