Hi! Gilles/Graham
This thread has suddenly "rattled my cage"! I remember that with my
Jabiru 3300 installation and the Petrol King Regulator I had to include
a Europa Part FS 01 restrictor in the return to tank line and understood
---From Andy Draper (I think) that this was necessary to maintain priority
to the carb supply.
However now I'm planning the 914 system for the new engine (when
Rotax/Skydrive honour me with it's delivery!) and I notice on the Europa
Instructions/fuel flow circuit there's no mention of the return line
restrictor.
Can I take it that adequate fuel flow to the carbs will ensue even
though the restrictor is now deleted?
I will be using 8mm bore pipe throughout supply and return.
Regards
Bob Harrison. G-PTAG
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Gilles
Thesee
Sent: 18 March 2007 21:34
Subject: Re: Europa-List: 914: fuel over airbox pressure
<Gilles.Thesee@ac-grenoble.fr>
Graham Singleton a crit :
> I'm not familiar with 914 but I do remember that the return flow from
> the regulator must be unrestricted otherwise the back pressure will
> cause rich mixture? Because of the high flow rate required with all
> pumps running the return pipe needs to be at least -6 size.
Graham,
You're right.
I recently conducted some tests to verify this point. I pressurized the
regulator to the max 1,3 bar absolute, while running the pump. All the
flow was by-passed by the regulator, with no problem to maintain the
specified ambient + 0.25 bar.
While I was perched on a ladder, doing the pressurizing with a U-tube,
my buddy sitting on the wing forgot to switch the different pumps, so
some additional tests are necessary.
Best regards,
Gilles
http://contrails.free.fr
|