X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 4004609 for flyrotary@lancaironline.net; Sun, 06 Dec 2009 03:03:11 -0500 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (sv1-1.per.aanet.com.au [203.24.100.68]) by poplet2.per.eftel.com (Postfix) with ESMTP id 7C8511737CE for ; Sun, 6 Dec 2009 16:02:28 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id ACE93BEC0CC for ; Sun, 6 Dec 2009 15:54:36 +0800 (WST) Message-ID: <13E19638D88D4F11973C0675916BB055@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Intake manifold runners Date: Sun, 6 Dec 2009 17:54:38 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001F_01CA769D.2D9BF8E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 091205-1, 12/05/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_001F_01CA769D.2D9BF8E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Rino, I'll take a guess at this and say that the smaller tubes should be = different lengths for maximum tuned benefit - however as the secondaries = are for lower RPM , tuning them would be pretty much a waste of time. = Would the same length and different diameter ( speed) have a = detrimental effect on optimum performance on the primaries? I just don't = know. Ed Anderson helped me with some maths to get to a theoretical length but = I just don't have it in front of me at the moment, but this would only = get you into the ball park as each motor is slightly different to other = installations. My calculations gave 21.36" for 2" PP. It would be = shorter lengths for smaller pipes as the velocity increases and could be = between 18" and 21" in my unqualified opinion. Testing is the only answer also my calculations may be on erroneous = assumptions. Hope that helps. George ( down under) What would be the prefered runner length to get the maximum power at = about 6200 rpm on the Renesis (6 intake ports). Is this a trick = question. Well, it is not a trick question , I want to build yet = another intake manifold. This is becoming a full time hobby for me. I will go for Ed's suggestion for 1 1/4" id for the two primaries and = 1 1/2" id for the two secondaries. Now tor the length? The present secondary runners are too large. Rino Lacombe -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_001F_01CA769D.2D9BF8E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Rino,

I'll take a guess at this and say that = the smaller=20 tubes should be different lengths for maximum tuned benefit - = however as=20 the secondaries are for lower RPM , tuning them would be pretty much a = waste of=20 time. Would the same length and different diameter ( speed) = have a=20 detrimental effect on optimum performance on the primaries? I just don't = know.

Ed Anderson helped me with some maths = to get to a=20 theoretical length but I just don't have it in front of me at the = moment, but=20 this would only get you into the ball park as each motor is slightly = different=20 to other installations. My calculations gave 21.36" for 2" PP. It would = be=20 shorter lengths for smaller pipes as the velocity increases and could be = between=20 18" and 21" in my unqualified opinion.

Testing is the only answer also my = calculations may be on erroneous assumptions.

Hope that helps.

George ( down under)

What = would be the=20 prefered runner length to get the maximum power at about 6200 rpm on the = Renesis=20 (6 intake ports). Is this a trick question. Well, it is not = a trick=20 question , I want to build yet another intake manifold. This is = becoming a=20 full time hobby for me.

I = will go for Ed's=20 suggestion for 1 1/4" id for the two primaries and 1 1/2" id for the = two=20 secondaries. Now tor the length?

The = present=20 secondary runners are too large.

Rino=20 Lacombe

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