Return-Path: Received: from sccrmhc12.comcast.net ([204.127.202.56] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 593532 for flyrotary@lancaironline.net; Thu, 06 Jan 2005 13:07:31 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.202.56; envelope-from=n3773@comcast.net Received: from rv8 (c-24-21-140-241.client.comcast.net[24.21.140.241]) by comcast.net (sccrmhc12) with SMTP id <2005010618065701200qh5pge>; Thu, 6 Jan 2005 18:06:57 +0000 Message-ID: <001801c4f41a$c3af0210$f18c1518@rv8> Reply-To: "kevin lane" From: "kevin lane" To: "Rotary motors in aircraft" References: Subject: exhaust port shape Date: Thu, 6 Jan 2005 10:08:42 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0015_01C4F3D7.B34E0710" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0015_01C4F3D7.B34E0710 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I decided to have my exhaust flanges recut to better match the ports. = Originally I simply had a 2" dia hole. How important is it to match the = shape of the ports, which is a collection of radiuses, straight sides, = fillets and even a sort of non-tangential "fillet". It appears that a 1 = 7/8" OD tube could be hammered to match this shape if I had it cut in = the flange. A 2" OD tube left round also looks like it would cover the = port, but would leave edges where the straight edges of the port would = dump into a round pipe. These areas are very small. My welder says = that he routinely hammers exhaust pipes into "square" shapes, that the = ports usually aren't round anyways. He can stretch the pipe to a bigger = dia., although I don't think that is a great idea, despite my using = 1/16" wall 321 s/s. I realize that I don't want the exhaust gas to = collide with a smaller exhaust pipe shape, but what about a larger size? = Is it OK to spill into a slightly larger size? Am I worrying too much = about a small detail, or is this worth the time and effort? Kevin Lane Portland, OR e-mail-> n3773@comcast.net web-> http://home.comcast.net/~n3773 (browse w/ internet explorer) ------=_NextPart_000_0015_01C4F3D7.B34E0710 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I decided to have my exhaust = flanges=20 recut to better match the ports. Originally I simply had a 2" dia=20 hole. How important is it to match the shape of the ports, which = is a=20 collection of radiuses, straight sides, fillets and even a sort of=20 non-tangential "fillet". It appears that a 1 7/8" OD tube could be = hammered to match this shape if I had it cut in the flange. A 2" = OD tube=20 left round also looks like it would cover the port, but would leave = edges=20 where the straight edges of the port would dump into a round pipe. = These=20 areas are very small. My welder says that he routinely hammers = exhaust=20 pipes into "square" shapes, that the ports usually aren't round = anyways. =20 He can stretch the pipe to a bigger dia., although I don't think that is = a great=20 idea, despite my using 1/16" wall 321 s/s. I realize that I don't = want the=20 exhaust gas to collide with a smaller exhaust pipe shape, but what about = a=20 larger size? Is it OK to spill into a slightly larger size? = Am I=20 worrying too much about a small detail, or is this worth the time and=20 effort?

Kevin Lane Portland, = OR
e-mail-> n3773@comcast.net
web-> http://home.comcast.net/~n3773
(browse=20 w/ internet explorer)

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