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 5.3.6) with ESMTP id 4250576 for flyrotary@lancaironline.net; Thu, 06 May 2010 19:39:23 -0400 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 (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id 03869173822 for ; Fri, 7 May 2010 07:38:31 +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 BFD4EBEC05D for ; Fri, 7 May 2010 07:36:11 +0800 (WST) Message-ID: <75071A6D9214457F9B385CDB5EB9646B@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Gravity Feed Date: Fri, 7 May 2010 09:36:14 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01CAEDC8.BCB808A0" 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 100506-1, 05/06/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0007_01CAEDC8.BCB808A0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Todd,=20 I would like to hear how they work out for you. George (down under) It's a smaller pport that retains balanced side ports, too. Todd =20 On Thu, May 6, 2010 at 1:50 PM, George Lendich = wrote: Todd, What do you mean by a semi PP. George (down under) 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 least a minimum pressure available. Anything aerobatic or low wing = will need pumps. Bill Jepson =20 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 ------=_NextPart_000_0007_01CAEDC8.BCB808A0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Todd,
I would like to hear how they work out = for=20 you.
George (down under)
It's a smaller pport that retains balanced side ports, too.
 
Todd
 


 
On Thu, May 6, 2010 at 1:50 PM, George = Lendich <lendich@aanet.com.au> = wrote:
 
 Todd,
What do you mean by a semi = PP.
George (down under)
 
Bill,
Sorry, it's a high wing (Bearhawk) that = won't be=20 upside down - ever.  I figured the airframe would give me 1.5 = psi=20 for a downdraft carb; maybe 2 psi for an updraft?  = I always=20 thought I would be totally electronic but I love the setup on my = 170: all=20 gravity from both tanks all the time.  The only fuel-related = activity=20 I have is making sure there is enough and then regularly sumping = tanks and=20 keeping the gascolater screen clean.
 
I am building a semi-pport and will try = to run it=20 with a gravity-fed Holley 2300.  At worst, I might have to = add a pump=20 or go with a Marvel Schebler MA-4/5 caliber aircraft carb.
 
Todd
 

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

 

 

Anyone who=20 knows feel free to explain to me why a Marvel-Schebler updraft = can feed=20 300 hp with gravity but pumps are needed for Webers or = Holleys.  I=20 understand the updraft gets another 18=94 of pressure but am = assuming it=20 is simply by design that the response is improved with a few lbs = of=20 pressure.  Since we aren=92t too worried about throttle = response as=20 long as it doesn=92t stumble, would a gravity-fed Holley be a = waste of=20 time?

 

Todd

 

 



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