X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from alnrmhc11.comcast.net ([204.127.225.91] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2197529 for flyrotary@lancaironline.net; Wed, 25 Jul 2007 01:15:26 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.225.91; envelope-from=n3773@comcast.net Received: from rv8 (c-76-27-238-77.hsd1.or.comcast.net[76.27.238.77]) by comcast.net (alnrmhc11) with SMTP id <20070725051428b1100gg0q3e>; Wed, 25 Jul 2007 05:14:48 +0000 Message-ID: <003101c7ce7a$b7c261d0$4dee1b4c@rv8> Reply-To: "kevin lane" From: "kevin lane" To: "flyrotary" Subject: bench flowtest Date: Tue, 24 Jul 2007 22:13:38 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002C_01C7CE3F.E2B7DB30" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_002C_01C7CE3F.E2B7DB30 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable while digesting all the responses to my questions about EFI I came = across this article, = http://www.neverworld.net/socalnetscum/files/tech/CarbShoot.pdf , on a = bench flow test for Harley carbs. what surprised me was how finicky and = unpredictable any modifications were. it also struck me how dirt simple = the Harley intake was, a "Y" all of a few inches long, yet it dropped = flow performance 20-30%! this makes me wonder how the intakes we = fabricate would measure up, with all the bends, joints, AL to rubber to = AL and such. no wonder my Lycoming can run 150 degrees different = between cylinders, and that polishing ports makes a difference. so, I can easily see the point of using software to tune the final = design vs. trying different mechanical combinations. that doesn't = address air flow routes thru the intake manifold tho, just fixes the = individual air/fuel mixtures arriving at each rotor. next wonderment - why are exhaust manifolds typically designed to get = larger dia. as more tubes attach downstream (as with the waste plumbing = in buildings), when, in reality, the flow is thru only one tube at a = time? kevin (turrentine renesis coming soon!) ------=_NextPart_000_002C_01C7CE3F.E2B7DB30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

while digesting all the responses to = my=20 questions about EFI I came across this article, = http://www.neverworld.net/socalnetscum/files/tech/CarbShoot.pdf = ,=20 on a bench flow test for Harley carbs. what surprised me was how = finicky=20 and unpredictable any modifications were. it also struck me = how dirt=20 simple the Harley intake was, a "Y" all of a few inches long, yet it = dropped=20 flow performance 20-30%! this makes me wonder how the intakes we = fabricate=20 would measure up, with all the bends, joints, AL to rubber to AL and = such. =20 no wonder my Lycoming can run 150 degrees different between cylinders, = and that=20 polishing ports makes a difference.

so, I can easily see the point of = using software=20 to tune the final design vs. trying different mechanical = combinations. =20 that doesn't address air flow routes thru the intake manifold tho, just = fixes=20 the individual air/fuel mixtures arriving at each rotor.

next wonderment - why are exhaust = manifolds=20 typically designed to get larger dia. as more tubes attach = downstream (as=20 with the waste plumbing in buildings), when, in reality, the flow is = thru only=20 one tube at a time? kevin (turrentine renesis coming=20 soon!)

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