X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-yw0-f184.google.com ([209.85.211.184] verified) by logan.com (CommuniGate Pro SMTP 5.3.6) with ESMTP id 4250066 for flyrotary@lancaironline.net; Thu, 06 May 2010 12:44:23 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.211.184; envelope-from=archerwt@gmail.com Received: by ywh14 with SMTP id 14so105373ywh.25 for ; Thu, 06 May 2010 09:43:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=ARFDxTW2pfkB99zPVahNuLMGY0kaeoWdCQhs9XfqwH4=; b=rmW9p0UgO4IW0uIa7/MJiaaI6n0rKU4G2j30hqcj0ayhVEnXXGPUlnHtT027KK8nFE ofB8nZFcrLibvCrglSR0lVsBoITSdPjY3O4cTRNSFeY7PEJHsEmeKxA3FrOU54IVj62X KKeZfNHbJW9dgi4ifeFMSBwtnKIe4+vji8NpM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=wSkp+3YUbi44D2EQnLs2dDTTcF1hsExMRN980X+AVod3TS2jj70nLkihfwyWOugTyd 4ddHJkUFlRdCcJ3S/FzARKm0bvnWGvTO5QzCRayGBrgZkvECN8t53Sw9+d2wm0pD/gWc KDejtN3YYFet3RDBFSV7UQhuX+0stwq9a4V0o= MIME-Version: 1.0 Received: by 10.100.146.18 with SMTP id t18mr8912828and.19.1273164225708; Thu, 06 May 2010 09:43:45 -0700 (PDT) Received: by 10.100.123.12 with HTTP; Thu, 6 May 2010 09:43:45 -0700 (PDT) In-Reply-To: References: Date: Thu, 6 May 2010 09:43:45 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Gravity Feed From: William Archer To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016e64601a86a03b90485efa5fd --0016e64601a86a03b90485efa5fd Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Bill, Sorry, it's a high wing (Bearhawk) that won't be upside down - ever. I figured the airframe would give me 1.5 psi for a downdraft carb; maybe 2 psi for an updraft? I always thought I would be totally electronic but I love the setup on my 170: all gravity from both tanks all the time. The only fuel-related activity I have is making sure there is enough and then regularly sumping tanks and keeping the gascolater screen clean. I am building a semi-pport and will try to run it with a gravity-fed Holley 2300. At worst, I might have to add a pump or go with a Marvel Schebler MA-4/5 caliber aircraft carb. Todd Todd, > High wing or low wing? The key is if you have a high wing there is at lea= st > a minimum pressure available. Anything aerobatic or low wing will need > pumps. > Bill Jepson > > > > > > Anyone who knows feel free to explain to me why a Marvel-Schebler updraft > can feed 300 hp with gravity but pumps are needed for Webers or Holleys. = I > understand the updraft gets another 18=94 of pressure but am assuming it = is > simply by design that the response is improved with a few lbs of pressure= . > Since we aren=92t too worried about throttle response as long as it doesn= =92t > stumble, would a gravity-fed Holley be a waste of time? > > > > Todd > > > > > --0016e64601a86a03b90485efa5fd Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Bill,
Sorry, it's a high wing (Bearhawk) that won&= #39;t be upside down - ever. =A0I figured the airframe would give me 1.5 ps= i for=A0a downdraft carb; maybe 2 psi=A0for an updraft?=A0 I always thought= I would be totally electronic but I love the setup on my 170: all gravity = from both tanks all the time.=A0 The only fuel-related activity I have is m= aking sure there is enough and then regularly sumping tanks and keeping the= gascolater screen clean.
=A0
I am building a semi-pport and will try to run i= t with a gravity-fed Holley 2300.=A0 At worst, I might have to add a pump o= r go with a Marvel Schebler MA-4/5 caliber aircraft carb.
=A0
Todd
=A0

Todd,
High wing or low = wing? The key is if you have a high wing there is at least a minimum pressu= re available. Anything aerobatic or low wing will need pumps.
Bill Jepso= n=A0=20

=A0

<= /div>

Anyone who knows feel = free to explain to me why a Marvel-Schebler updraft can feed 300 hp with gr= avity but pumps are needed for Webers or Holleys.=A0 I understand the updra= ft gets another 18=94 of pressure but am assuming it is simply by design th= at the response is improved with a few lbs of pressure.=A0 Since we aren=92= t too worried about throttle response as long as it doesn=92t stumble, woul= d a gravity-fed Holley be a waste of time?

=A0

Todd

=

=A0

<= /div>

=A0

<= /div>

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