Return-Path: Received: from out007.verizon.net ([206.46.170.107] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 547539 for flyrotary@lancaironline.net; Sat, 27 Nov 2004 13:31:48 -0500 Received-SPF: pass receiver=logan.com; client-ip=206.46.170.107; envelope-from=finn.lassen@verizon.net Received: from verizon.net ([4.12.145.173]) by out007.verizon.net (InterMail vM.5.01.06.06 201-253-122-130-106-20030910) with ESMTP id <20041127183115.OECD1327.out007.verizon.net@verizon.net> for ; Sat, 27 Nov 2004 12:31:15 -0600 Message-ID: <41A8C7F2.4090403@verizon.net> Date: Sat, 27 Nov 2004 13:31:14 -0500 From: Finn Lassen User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax; PROMO) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Bubbles in fuel line from pump - new valve References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------080608060806020905050009" X-Authentication-Info: Submitted using SMTP AUTH at out007.verizon.net from [4.12.145.173] at Sat, 27 Nov 2004 12:31:15 -0600 This is a multi-part message in MIME format. --------------080608060806020905050009 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Yes, I'm using only auto fuel. Removing the sensor definitely improved the situation in past tests. I guess I should try removing it now that I have eliminated "U"s (possible air pockets) in the lines and use a simple shut off valve. Actually the outlet from the tank is probably too small. 1/8" NPT to 3/8" barb brass fitting drilled out to the point where I hoped the threads were still strong enough to not break, if I remember correctly. I'm not sure if I have enough material in the tank to go up to 1/4" NPT fitting. Will have to look at that when I get around to taking out the tank. Finn Dale Rogers wrote: >>Can the explanation be that the sudden change in velocity/pressure >>caused by such a restriction cause the fuel to boil (evaporate)? >> >>Finn >> >> > > Especially if you're using auto fuel. Any way you >can shunt around, or replace, the flow meter for a test? >Ordinarily, for a 5/16" line between pump and engine, I'd >expect to see a 3/8" or 7/16" pump supply. > >Dale R. >COZY MkIV #1254 > > > --------------080608060806020905050009 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Yes, I'm using only auto fuel. Removing the sensor definitely improved the situation in past tests. I guess I should try removing it now that I have eliminated "U"s (possible air pockets) in the lines and use a simple shut off valve.

Actually the outlet from the tank is probably too small. 1/8" NPT to 3/8" barb brass fitting drilled out to the point where I hoped the threads were still strong enough to not break, if I remember correctly. I'm not sure if I have enough material in the tank to go up to 1/4" NPT fitting. Will have to look at that when I get around to taking out the tank.

Finn

Dale Rogers wrote:

Can the explanation be that the sudden change in velocity/pressure 
caused by such a restriction cause the fuel to boil (evaporate)?

Finn


   Especially if you're using auto fuel.  Any way you 
can shunt around, or replace, the flow meter for a test?
Ordinarily, for a 5/16" line between pump and engine, I'd 
expect to see a 3/8" or 7/16" pump supply.

Dale R.
COZY MkIV #1254

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