X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from hs-out-0708.google.com ([64.233.178.247] verified) by logan.com (CommuniGate Pro SMTP 5.2.1) with ESMTP id 2812573 for flyrotary@lancaironline.net; Fri, 21 Mar 2008 20:28:40 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.233.178.247; envelope-from=rwstracy@gmail.com Received: by hs-out-0708.google.com with SMTP id x43so1481966hsb.3 for ; Fri, 21 Mar 2008 17:28:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:sender:to:subject:in-reply-to:mime-version:content-type:references:x-google-sender-auth; bh=dJesuZGajL9vq4Sshvs6Jr0xv2yzMt8X3HpnVt448GY=; b=kweBlsz83Kbm+fwzho/k6CuaFsGMguEBY+8dwmYnlxS0pVoMAuuwPDZCJnCefqopUi8FJ8MOd/TRN8HYmwCb5kKye0yrTY4Vw70CgVQxG95KsdBohDgErhNRb1MUoBbxejsAh7l55jP6D8kwSE1Eil1M93qPEtPNKVrRRuYc0B8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:sender:to:subject:in-reply-to:mime-version:content-type:references:x-google-sender-auth; b=LFPUgmVmhrIEZ/NtpGbtNkSFch+AaiSpR0cySzIVmqY5PKh7YigVeZIfizoPFDVjrKG31LtFKGoJh2h8z0feW9nA2dd/8QodpXUBbdEKdjz38BQITX0Uc2W5E2osyyQ4cvuysKyGJ0r/Z6udUqWr3vrUQ3lpMlCLzR9k5AhEvmM= Received: by 10.100.14.2 with SMTP id 2mr10500663ann.16.1206145683067; Fri, 21 Mar 2008 17:28:03 -0700 (PDT) Received: by 10.100.133.10 with HTTP; Fri, 21 Mar 2008 17:28:03 -0700 (PDT) Message-ID: <1b4b137c0803211728o50ee86e1oa20662291240d7fe@mail.gmail.com> Date: Fri, 21 Mar 2008 20:28:03 -0400 From: "Tracy Crook" Sender: rwstracy@gmail.com To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Gravity fed carb? peer review In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_4000_12225206.1206145683057" References: X-Google-Sender-Auth: 3fb8ea2b04f25761 ------=_Part_4000_12225206.1206145683057 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline A big factor in carb manifold design is mixture distribution. Not always easy. That was the object of those horrid T shaped junctions seen on some aero VW conversions. Really bad turbulance and pressure loss but it mixed up the mixture pretty good. The advantage of using separate barrels (or carbs) for each rotor is that mixture distribution is assured. Aside from that, your runners are very short so not a lot of ram tuning effect. The long single runner from the carb doesn't count as it contributes nothing to tuning. But if all you need is 150 - 160 HP it will work OK (assuming you do get good mixture distribution). Tracy On Fri, Mar 21, 2008 at 6:47 PM, Michael Silvius wrote: > In the pursuit of ultimate simplicity I have been contemplating the notion > of a gravity fed carbureted system for my Falconar project. A while back I > made up a 3 carb rig like Tracy's original set up but that would still > require fuel pumps from my nose tank. I really would like to try for a > purely gravity fed system. Here are some pix of a couple of options using > a > 3x3 inch box manifold similar to what George Anderson used on his canard > but > instead of a single top mounted Dodge 318 carb as he did I am proposing a > long intake runner dropping down to the bottom edge of the firewall to a > single Stromberg carb. > > Opinions, comments, suggestions, jokes? > > Any one see any obvious problems with such a set up? > > Of principal concern is the intake runner feeding the manifold plenum box > from one end. > > Michael Silvius > > Scarborough, Maine > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > ------=_Part_4000_12225206.1206145683057 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
A big factor in carb manifold design is mixture distribution.  Not always easy.  That was the object of those horrid T shaped junctions seen on some aero VW conversions.  Really bad turbulance and pressure loss but it mixed up the mixture pretty good.  The advantage of using separate barrels (or carbs) for each rotor is that mixture distribution is assured.  
Aside from that, your runners are very short so not a lot of ram tuning effect.  The long single runner from the carb doesn't count as it contributes nothing to tuning.   But if all you need is 150 - 160 HP it will work OK (assuming you do get good mixture distribution).
 
Tracy

 
On Fri, Mar 21, 2008 at 6:47 PM, Michael Silvius <silvius@gwi.net> wrote:
In the pursuit of ultimate simplicity I have been contemplating the notion
of a gravity fed carbureted system for my Falconar project. A while back I
made up a 3 carb rig like Tracy's original set up but that would still
require fuel pumps from my nose tank. I really would like to try for a
purely gravity fed system. Here are some pix of a couple of options using a
3x3 inch box manifold similar to what George Anderson used on his canard but
instead of a single top mounted Dodge 318 carb as he did I am proposing a
long intake runner dropping down to the bottom edge of the firewall to a
single Stromberg carb.

Opinions, comments, suggestions, jokes?

Any one see any obvious problems with such a set up?

Of principal concern is the intake runner feeding the manifold plenum box
from one end.

Michael Silvius

Scarborough, Maine

--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html


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