X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-yi0-f52.google.com ([209.85.218.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTPS id 5109046 for flyrotary@lancaironline.net; Wed, 31 Aug 2011 00:14:34 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.218.52; envelope-from=david.staten@gmail.com Received: by yie13 with SMTP id 13so599835yie.25 for ; Tue, 30 Aug 2011 21:13:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type; bh=ucp2r5ftkg7QY4r6MMzNK4PVN5BQXwjBSptl57yWEqo=; b=Phct8rW+a/d3l2qXTKZRdAru7g7JRlwydvCQeJPk2ON7YEBMzrDeTn6MhnXO1pok/I 1Vb8wQqSbxbgJ41KI08A8+303r/iD6F1+zNZWrL0D5TfGCU4FaGhDx336sMfGjPhrJ0k hYm+Dms7FYW012yc3PcnKcwo0YkFt0muDHzQg= Received: by 10.42.154.135 with SMTP id q7mr907154icw.87.1314764037934; Tue, 30 Aug 2011 21:13:57 -0700 (PDT) Return-Path: Received: from [127.0.0.1] ([216.80.140.47]) by mx.google.com with ESMTPS id i9sm2756857ibo.12.2011.08.30.21.13.56 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 30 Aug 2011 21:13:57 -0700 (PDT) Message-ID: <4E5DB509.8070101@gmail.com> Date: Tue, 30 Aug 2011 23:14:01 -0500 From: Dave User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:6.0) Gecko/20110812 Thunderbird/6.0 MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: CG Products Intake Manifold References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------070909090508090604040100" This is a multi-part message in MIME format. --------------070909090508090604040100 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit HOWEVER..... if there is not a method to bleed down the rail the risk of vapor lock exists, as the rail heats, the fuel boils, and the vapor gets trapped in the line. If you DO put the regulator upstream of the rail, its imperative to be able to be able to flow fuel past the injectors and to a return line to avoid any possibility of vapor lock. The easiest way is simply to put the regulator downstream of the rail and injectors, but again.. this arrangement is more about preventing vapor lock, not ensuring adequate pressure. Chris and I were forced into the upstream approach by the Mistral fuel rail configuration, and I didn't want to mess with drilling out the pinhole and then running a regulator downstream - Mistral was hard enough to get the intake from, and we didn't expect getting a replacement part if we had an OOOPS would have been easy. As others have now found out, Mistral isn't selling parts. So... anyways.. just wanted to clarify previous post. 1) can regulate pressure anywhere in the fuel circuit between pumps and injectors. 2) Must provide for mechanism to flow fuel past injectors to prevent vapor lock. Dave On 8/30/2011 11:06 PM, Dave wrote: > No... at the flows and pressures we are using (and barring any major > obstructions between the regulator and the injectors), the regulator > can be anywhere in the circuit and adequately regulate the pressure. > > On Chris Barber's install, I purchased the Mistral intake for use on > his engine. The fuel rail was a dead end tube with a pinhole on the > end. Presumably the pinhole was to prevent vapor lock in the fuel > rail. The regulator HAD to be upstream of the injectors when using the > intake. We had stable fuel pressures and no problems getting fuel to > the engine. > > We had return lines from the pinhole end of the rail, as well as from > the pressure regulator, that fed back to the sump tank. Since there > were not check valves running from the wings to the sump, there was no > chance of pressurizing the sump. > > Dave > > On 8/30/2011 10:30 PM, CozyGirrrl@aol.com wrote: >> Ed, I must have mispoke to give this impression, I thought the >> pressure reg HAD TO be last in line to maintain pressure in the fuel >> rail? >> Chrissi & Randi >> www.CozyGirrrl.com >> CG Products, Custom Aircraft Hardware >> Chairwomen, Sun-N-Fun Engine Workshop >> In a message dated 8/30/2011 10:13:53 P.M. Central Daylight Time, >> eanderson@carolina.rr.com writes: >> >> If the pressure regulator is place before the injectors then >> there is less fresh fuel flowing through the rails. >> > --------------070909090508090604040100 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit HOWEVER..... if there is not a method to bleed down the rail the risk of vapor lock exists, as the rail heats, the fuel boils, and the vapor gets trapped in the line.

If you DO put the regulator upstream of the rail, its imperative to be able to be able to flow fuel past the injectors and to a return line to avoid any possibility of vapor lock. The easiest way is simply to put the regulator downstream of the rail and injectors, but again.. this arrangement is more about preventing vapor lock, not ensuring adequate pressure.

Chris and I were forced into the upstream approach by the Mistral fuel rail configuration, and I didn't want to mess with drilling out the pinhole and then running a regulator downstream - Mistral was hard enough to get the intake from, and we didn't expect getting a replacement part if we had an OOOPS would have been easy. As others have now found out, Mistral isn't selling parts.

So... anyways.. just wanted to clarify previous post.  1) can regulate pressure anywhere in the fuel circuit between pumps and injectors. 2) Must provide for mechanism to flow fuel past injectors to prevent vapor lock.

Dave

On 8/30/2011 11:06 PM, Dave wrote:
No... at the flows and pressures we are using (and barring any major obstructions between the regulator and the injectors), the regulator can be anywhere in the circuit and adequately regulate the pressure.

On Chris Barber's install, I purchased the Mistral intake for use on his engine. The fuel rail was a dead end tube with a pinhole on the end. Presumably the pinhole was to prevent vapor lock in the fuel rail. The regulator HAD to be upstream of the injectors when using the intake. We had stable fuel pressures and no problems getting fuel to the engine.

We had return lines from the pinhole end of the rail, as well as from the pressure regulator, that fed back to the sump tank. Since there were not check valves running from the wings to the sump, there was no chance of pressurizing the sump.

Dave

On 8/30/2011 10:30 PM, CozyGirrrl@aol.com wrote:
Ed, I must have mispoke to give this impression, I thought the pressure reg HAD TO be last in line to maintain pressure in the fuel rail?
 
 
Chrissi & Randi
www.CozyGirrrl.com
CG Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop
 
In a message dated 8/30/2011 10:13:53 P.M. Central Daylight Time, eanderson@carolina.rr.com writes:
  If the pressure regulator is place before the injectors then there is less fresh fuel flowing through the rails. 


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