Received-SPF: pass
 receiver=logan.com; client-ip=66.133.182.164; envelope-from=canarder@frontiernet.net
Message-ID: <42AF34B1.4090200@frontiernet.net>
Date: Tue, 14 Jun 2005 14:49:05 -0500
From: Jim Sower <canarder@frontiernet.net>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040514
MIME-Version: 1.0
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: fuel pump mounting ( fuel system architecture)
References: <list-1001838@logan.com>
In-Reply-To: <list-1001838@logan.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

OK  This is what I've been trying to find out - whether it will reprime 
with downstream head pressure (like connected to rail, regulator).  
You've convinced me it won't.  Successful reprime with bleed circuit 
sort of confirms my plan to put a "permanent" bleed circuit from a 
deliberate high spot in the high pressure circuit upstream from the rail 
back to the supply tank.
Should help with both reprime and vapor lock issues ... Jim S.

Mark R Steitle wrote:

>John, 
>At risk of repeating myself, I would like to add to John's comments.  
>
>I ran a similar test, but included the rest of the fuel system (Andair
>valve, fuel filters, fuel rail, fuel pressure regulator, etc.) and found
>out that my system would not reprime unless I cracked open a line
>downstream of the pump.  With the addition of the bypass bleed circuit,
>I have confirmed that one dry pump will draw fuel up from the floor
>(approx. 18") through the Andair valve and be up to pressure in about 10
>seconds.  "Time to prime" is significantly reduced by running both
>pumps.  I have repeated the test using auto fuel in hot Texas temps and
>get similar results. 
>
>Mark S.
>Lancair ES w/20B
>
>
>-----Original Message-----
>From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
>Behalf Of John Slade
>Sent: Tuesday, June 14, 2005 1:27 PM
>To: Rotary motors in aircraft
>Subject: [FlyRotary] Re: fuel pump mounting ( fuel system architecture)
>
>  
>
>>>I did an experiment with the pump on a 4 foot bench, and a gas can
>>>on the
>>>floor. The pump primed itself with no difficulty. Having said that,
>>>a
>>>scenario like this in a plane would be just asking for vapor lock.
>>>
>>>      
>>>
>>-----------------------------------------------
>>
>>Hi John, I like your test but do not understand your conclusion.
>>    
>>
>The conclusion wasn't based on the results of the experiment :)
>It's my understanding that you need to replicate the temperatures and
>pressures for the experiment to be entirely valid.
>
>  
>
>>If the pump will prime with a 4 foot negative head that sounds good to
>>    
>>
>me.
>But this only proves it works on the bench under atmospheric pressure
>and
>ambient temperature.
>
>John
>
>
>
>  
>
>>> Homepage:  http://www.flyrotary.com/
>>> Archive:   http://lancaironline.net/lists/flyrotary/List.html
>>>      
>>>
>
>  
>
>>> Homepage:  http://www.flyrotary.com/
>>> Archive:   http://lancaironline.net/lists/flyrotary/List.html
>>>      
>>>
>
>
>  
>