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George (down under),
My bleed circuit is about midway up on the firewall, and definitely not
at the highest point in the system. I'm not convinced that it needs to
be at the highest point. The reason is that if you have an airlock,
preventing the pump from priming, the engine won't be running at that
time. As soon as the pump is able to re-prime, it will start flowing
30+ gpm of fuel. If you're returning fuel back to the tank, the air
will be forced out of the fuel rail and back to the tank, and you're
back in business. This is a bit different approach from what Leon posted, so there may be
some merit to having the bleed at the highest point. It certainly
wouldn't hurt any, but I have had positive results with my system and
placing it near the pressure regulator made the plumbing simpler.
Mark S.
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Tuesday, June 14, 2005 5:37 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Engine Not Starting
Mark,
You must be psychic, you reading my mind on the vapour and air bubbles.
I was thinking of making a fuel rail in an inverted ( but flatter) V
shape
and having the by-pass at the apex. But in a bump in the line prior to
the
rail is just as good and perhaps easier to install.
George ( down under)
I'm putting a bypass like that in the highest point of my fuel line
(between pump and rail) as I think it will also prevent, or at the
very
least, alleviate, a vapor lock situation. A .030 or .040 jet will pass
a
LOT of air/vapor but not enough fuel to impact anything.
Or that's my bet anyway ... Jim S.
Mark R Steitle wrote:
> George,
>
> That may have been me following Paul Conner's first engine-out
> landing. I picked up the idea from the Eggenfellner Subaru group.
They
> had had a couple of instances where pilots ran one tank dry and then
> couldn't get the EFI pump to re-prime, and ended up in off-field
> landings. It is now a mandatory change for anyone running the
> Eggenfellner package. I used a small carburetor jet from my stash of
> 2-cycle motorcycle jets. It was about .020-025" and installed so as
to
> bypass the pressure regulator, bleeding air back through the fuel
> return line. I have tested my setup and it allows enough pressure
> relief to permit the pump to re-prime if I run a tank dry. Before
> installing the bypass bleeder circuit, it would not re-prime unless
I
> cracked open a line downstream of the pump.
>
> Mark S.
>
>
------------------------------------------------------------------------
>
> *From:* Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
> *On Behalf Of *Kelly Troyer
> *Sent:* Monday, June 13, 2005 8:23 PM
> *To:* Rotary motors in aircraft
> *Subject:* [FlyRotary] Re: Engine Not Starting
>
> Georges & George,
>
> I used a .020 thousands (.508 mm) !
>
> --
> Kelly Troyer
> Dyke Delta/13B/RD1C/EC2
>
>
> -------------- Original message from "George Lendich"
> <lendich@optusnet.com.au>: --------------
>
>
> Georges,
>
> Very small is my guess, someone on here gave that suggestion
> some time ago and I can't remember the size they suggested.
> It's just to relieve the pressure after shut down. The loss
> during running is so small as not to matter.
>
> I thought it was a great idea !
>
> George ( down under)
>
> What maximum size orifice would you use in the bypass hose?
>
> Georges B.
>
> /-------Original Message-------/
>
> */From:/* Rotary motors in aircraft
> <mailto:flyrotary@lancaironline.net>
>
> */Date:/* 06/13/05 15:50:42
>
> */To:/* Rotary motors in aircraft
> <mailto:flyrotary@lancaironline.net>
>
> */Subject:/* [FlyRotary] Re: Engine Not Starting
>
>> 3. Always stop the engine by turning off the fuel pump, so that
>
>> there is no fuel pressure in the line. Otherwise, unburned
> fuel may
>
>> leak from the still pressurized injectors into the rotors and
> increase
>
>> the chances of hard starting or flooding the next time you
> try to start
>
>> the engine.
>
> Bob,
>
> The suggested low volume by-pass hose ( by passing the fuel
> pressure
>
> regulator) will also solve that problem.
>
> George ( down under)
>
> .
>
>
>
>
>
>> Homepage: http://www.flyrotary.com/
>> Archive: http://lancaironline.net/lists/flyrotary/List.html
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