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Date: Sun, 06 Jun 2010 09:37:06 -0500
From: Charlie England <ceengland@bellsouth.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: high/low pressure pumps question
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I thought about that after I had hit 'send'. My pumps will probably be 
on the floor with a shorter run from the main tank than yours, but it 
would probably still be a good idea. If I could find a way to fit them 
in the wing root next to the main tank, that might change the 
requirement a bit. Also, I'm hoping to avoid getting any engine heat 
into the fuel that flows through the pumps. The only heating should be 
from the pumps themselves.

Charlie

On 6/6/2010 9:05 AM, Ed Anderson wrote:
> Charlie,
>
> For what it's worth, your proposed fuel system is essentially the same as I
> am using with the exception - that I have a very small (like 1/2 pint)
> header tank at the junction of your "T".  But, I see no reason to believe
> that you proposed set-up would not work perhaps even better - no header tank
> on the FWF to absorb engine heat.  Mine has worked for 10+ years.
>
> However, I would suggest that you include a facet pump between the tanks and
> your set up - probably after your selector valve - for a couple of reasons.
>
> In the early days of my testing when I was doing power on stall testing, I
> discovered the combination of high power settings and low air flow through
> the cowl - could get my fuel in the header tank hot enough to percolate -
> never got vapor lock, but I could see the fuel pressure varying considerably
> and the engine would complain.  Turning on the facet pump apparently
> provided sufficient pressure to stifle the percolation.
>
> Plus it sort of "ensures" that you have a pump that will "Pull" fuel out of
> the tanks.  I always have it on for take off and landing.
>
> FWIW
>
>
> Ed
>
> Ed Anderson
>
> Rv-6A N494BW Rotary Powered
>
> Matthews, NC
>
> eanderson@carolina.rr.com
>
> http://www.andersonee.com
>
> http://www.dmack.net/mazda/index.html
>
> http://www.flyrotary.com/
>
> http://members.cox.net/rogersda/rotary/configs.htm#N494BW
>
> http://www.rotaryaviation.com/Rotorhead%20Truth.htm
>
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
> Behalf Of Charlie England
> Sent: Sunday, June 06, 2010 9:47 AM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: high/low pressure pumps question
>
> Hope this helps...
>
> On 6/6/2010 2:21 AM, Todd Bartrim wrote:
>    
>> Hi Charlie;
>> Hmmmnn, I gotta say a picture (or drawing) is worth a thousand words.
>> Todd (sent on my new-fangled google phone with a really damn small
>> keyboard)
>>
>>      
>>> On 2010-06-05 8:46 PM, "Charlie England"<ceengland@bellsouth.net
>>> <mailto:ceengland@bellsouth.net>>  wrote:
>>>
>>> Hi Todd,
>>>
>>> My thought is to set up the fuel path thus: fuel source through a T
>>> into injection pumps, through filters, through combining T, through
>>> the regulator(in cockpit), through firewall to engine. The
>>> regulator's bypass port (in the cockpit) would be plumbed just like
>>> yours, except no heat exchanger since the bypass fuel would never see
>>> the heat of the engine compartment. The bypass would still T into the
>>> supply to the injection pumps, like your system. Obviously, a
>>> manifold pressure line would be required through the firewall into
>>> the cockpit to the pressure regulator.
>>>
>>> My original plan (different injection that didn't require a return
>>> line) was similar to your selector setup: main tanks feeding stock
>>> van's selector, with the 3rd port on it being fed by a 2nd vans
>>> selector to select either of the 2 aux tanks. No transfer pump would
>>> have been required,&  no crossover valve. Failure of the primary
>>> valve could have been a 'show stopper', but the newer valves seem to
>>> be rock solid reliable. Going to this system using the gear type
>>> pumps requiring a return line forced re-thinking. Using your idea to
>>> return the bypassed fuel at the pump inlet effectively eliminates the
>>> 'return' issue,&  tempts me to return to the original fuel selector
>>> layout, with the addition of a Facet boost pump. The fact that the
>>> optical sensors will work looking into the side of a fuel line (the
>>> T), instead of needing them in the tank&  that they still give almost
>>> a full minute's warning, is very encouraging. I'll start looking for
>>> a convenient place to mount them.
>>>
>>> I hope that Tracy will chime in on how he plumbed the regulator on
>>> his -8.
>>>
>>> Many thanks for the extra details.
>>>
>>> Charlie
>>>
>>>
>>>
>>> On 6/5/2010 12:32 PM, Todd Bartrim wrote:
>>>
>>>      >
>>>      >  Hi Charlie
>>>      >     Not sure I understand correctly what you mean? Can you
>>>      sketch it out quickly? I'...
>>>
>>>      >  *From*: Charlie England<ceengland@bellsouth.net
>>>      <mailto:ceengland@bellsouth.net>
>>>      <mailto:Charlie%20England%20%3cceengland@bellsout.
>>>      <mailto:Charlie%2520England%2520%253cceengland@bellsout.>..
>>>
>>>      >  *Subject*: [FlyRotary] Re: high/low pressure pumps question
>>>      >  *Date*: Sat, 05 Jun 2010 08:38:09 -0...
>>>
>>>
>>>
>>> --
>>> Homepage: http://www.flyrotary.com/
>>> Archive and UnSub: http://mail.lancaironline.net:81/lists...
>>>
>>>        
>
>
> --
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