Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b2) with ESMTP id 3178804 for flyrotary@lancaironline.net; Mon, 19 Apr 2004 11:09:07 -0400 Received: from EDWARD (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i3JF94s2020866 for ; Mon, 19 Apr 2004 11:09:05 -0400 (EDT) Message-ID: <020a01c4261f$fbdddf40$2402a8c0@EDWARD> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: intake ideas? Date: Mon, 19 Apr 2004 11:07:08 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0207_01C425FE.7497E8D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0207_01C425FE.7497E8D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Actually, Rusty. I have always been fuel injected. My first manifold = was using 50 mm twin throat TMW Webber throttle body (with 4 injectors), = a racing beat webber DOE manifold which I flew on a 86 six port block. = I only had one flight on that engine with the new (longer smaller = diameter) manifold before my HALTECH fuel injection system failed, so = did not get a good comparison. However, on that one flight with the old = engine and new manifold I did note that my rate of climb increased by = 300 fpm over the old manifold. Certainly not a conclusive nor exhaust = test and comparison, but enough to convince me to keep the new manifold = when I installed the turbo block. In just about every theory of induction tuning I have looked at (and its = been quite a few), if they agreed on anything - it was longer, smaller = diameter tubes favored torque at lower rpms and short, larger diameter = tubes favored power at the higher rpms. Again, we are talking about = attempt to get an optimum match. That does not mean an engine will not = run nor produce power with less than an optimum setup - it just simply = won't be "optimum". And as I mentioned in an earlier e mail, there are = other considerations that may make a less than optimum setup desirable = or at least the lesser of the evils faced {:>) Ed Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Saturday, April 17, 2004 6:23 PM Subject: [FlyRotary] Re: intake ideas? The question of tuned runners is 'how much is the benefit?', and 'what = do you want to give up for it'. =20 Thanks to you both for the comments. I think Al hit the nail on the = head with the above statement. There are so many compromises that have = to be made, particularly when you don't have much room to work with. It = would be great to see a direct comparison of a short intake vs a nicely = tuned one. AFAIK, no one has done that. I know Ed had a short intake = in the past, but I'm thinking that he changed some other major items = (engine or fuel injection system?) at the same time he changed intakes, = which would invalidate the test. =20 I also agree about the injector placement, and I'm starting to think = the best arrangement is either to have the primaries in the block, and = secondaries in the TB, or all four injectors in the TB on a short = intake. Since I have both a 2 and a 4 injector version of the TWM TB, I = guess I can go either way on the next iteration. =20 BTW, Al, did you make that intake? It's beautiful! Cheers, Rusty (wishing I was home where I could start working on the new = intake) ------=_NextPart_000_0207_01C425FE.7497E8D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Actually, Rusty.  I have always = been fuel=20 injected.  My first manifold was using 50 mm twin throat TMW Webber = throttle body (with 4 injectors), a racing beat webber DOE manifold = which I flew=20 on a 86 six port block.  I only had one flight on that engine with = the new=20 (longer smaller diameter) manifold before my HALTECH fuel injection = system=20 failed, so did not get a good comparison.  However, on that one = flight with=20 the old engine and new manifold I did note that my rate of climb = increased by=20 300 fpm over the old manifold.  Certainly not a conclusive nor = exhaust test=20 and comparison, but enough to convince me to keep the new manifold when = I=20 installed the turbo block.
 
In just about every theory of induction = tuning I=20 have looked at (and its been quite a few), if they agreed on anything = - it=20 was longer, smaller diameter tubes favored torque at lower rpms and = short,=20 larger diameter tubes favored power at the higher rpms.  Again, we = are=20 talking about attempt to get an optimum match.  That does not mean = an=20 engine will not run nor produce power with less than an optimum setup - = it just=20 simply won't be "optimum".  And as I mentioned in an earlier e = mail, there=20 are other considerations that may make a less than optimum setup = desirable or at=20 least the lesser of the evils faced {:>)
 
 
Ed
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From:=20 Russell=20 Duffy
Sent: Saturday, April 17, 2004 = 6:23=20 PM
Subject: [FlyRotary] Re: intake = ideas?

The = question of=20 tuned runners is =91how much is the benefit?=92, and =91what do you = want to give up=20 for it=92.   
 
Thanks to you=20 both for the comments.  I think Al hit the nail on = the=20 head with the above statement.  There are so many = compromises that=20 have to be made, particularly when you don't have much room to work=20 with.  It would be great to see a direct comparison of a short = intake vs=20 a nicely tuned one.  AFAIK, no one has done that.  I = know Ed=20 had a short intake in the past, but I'm thinking that he changed some = other=20 major items (engine or fuel injection system?) at the same time he = changed=20 intakes, which would invalidate the test. =20
 
I also agree=20 about the injector placement, and I'm starting to think the best=20 arrangement is either to have the primaries in the block, and = secondaries=20 in the TB, or all four injectors in the TB on a short = intake.  Since=20 I have both a 2 and a 4 injector version of the TWM TB, I guess I = can go=20 either way on the next=20 iteration.  
 
BTW, Al, did=20 you make that intake?  It's = beautiful!
 
Cheers,
Rusty (wishing=20 I was home where I could start working on the new=20 intake)
 
 
 
 
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