The Murphy Builders Site

Hmmm - Maybe he wants the return to the top of the tank so that fuel
can't reverse flow from the tank to the engine in case of a leak or
fire...
Just a guess and could be totally wrong.

Guys have pumped all the fuel from one tank through the return to the
other tank and overboard with poorly designed soob systems but those use
a high pressure fuel pump and return a lot more fuel.

Ken

Jim Cole wrote:

Hi Charlie, I think either wing will work - it's just a case of which side
you want the return tube to run through the firewall and up to the tank.
Daniel Sasseville (eastern Canada Rotax rep) suggested that you run it
into
the top of the tank at the front - probably beside the site tube outlet.

Sounds like you're getting there. I also recommend Daniel's mount for the
912 as we moved the engine 3 inches further out from the firewall which
resulted in a good C of G, good baggage allowance, and I feel - a good
balanced "look".

Here's his link - just in case.
http://www.rotaxservice.com/about/index.htm

Cheers
Jim #333




On 9/17/2007 6:01 PM, "Charlie Eubanks" <charlie@troyairpark.com> wrote:

Jim

I am 90% sure I will be installing a 100 HP Rotax. I have already built
my
fuel tanks for two bays per side. I am at that point where I am
installing
the fuel outlet and sight gage fittings in the root rib. Have not
purchased
the Rotax yet so I am not familiar with the installation requirements.
Could
you recommend the best location for the fitting and in which wing?

Charlie E. 802R

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

Jim

I am 90% sure I will be installing a 100 HP Rotax. I have already built my
fuel tanks for two bays per side. I am at that point where I am installing
the fuel outlet and sight gage fittings in the root rib. Have not purchased
the Rotax yet so I am not familiar with the installation requirements.
Could you recommend the best location for the fitting and in which wing?

Charlie E. 802R

----- Original Message -----
From: "Jim Cole" <jcole@rangroup.com>
To: <rebel-builders@dcsol.com>
Sent: Monday, September 17, 2007 11:17 AM
Subject: Re: [rebel-builders] Rebel Builders Meeting

Thanks everyone, I really enjoyed sharing the trip pictures with everyone
and it sure was nice to see so many Rebels together in one spot. It even
beat the picture we have of the 5 Rebels lined up on the ramp in Sand
Point
Idaho.

I keep forgetting - but as I mentioned at the meeting, there are a couple
of
things that I would do if I was planning on using the 912ULS in a new
Rebel.
1 - The Rotax 912 has a 1/8th return line from the engine fuel system
that returns excess fuel to the tank. There is a small manifold (you
either need
to make one or buy one from Rotax) that has one line in from the fuel
pump,
2 - 1/4 inch outlets, one for each carb, and a 1/8 inch return line to
the fuel tank.
I would put a separate fitting into the root end of one wing tank to
accept
this line. My wing was built without it (I currently have the return line
"T" into my crossover tube - not great) and now I need to add the
fitting.
(going to do it when I have the wings off for painting) If I had a choice
I
would have preferred to do it while the wing was still open in order to
make
sure I don't get any drill bit shaving in the tank. So even if you
haven't made the final decision - put one in - you can always plug it if
you don't need it.
2 - I would also build the wings with 2 fuel bays - per side - I really
have too much fuel capacity for the 912. For instance I think it's better
to
have say 10 gallons of fuel in two bays versus spread out over 3 - better
head pressure and when banking - less chance of air entering the system.
I'm
sure I carried way too much weight, in fuel, on the trip.

Cheers
Jim

I would like to know more about this return line as well.....I have never
seen a 912UL or 912ULS with a fuel return line.

Wayne

----- Original Message -----
From: "Ken" <klehman@albedo.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, September 18, 2007 8:43 AM
Subject: [rebel-builders] rotax fuel return

Hmmm - Maybe he wants the return to the top of the tank so that fuel
can't reverse flow from the tank to the engine in case of a leak or
fire...
Just a guess and could be totally wrong.

Guys have pumped all the fuel from one tank through the return to the
other tank and overboard with poorly designed soob systems but those use
a high pressure fuel pump and return a lot more fuel.

Ken

Jim Cole wrote:

Hi Charlie, I think either wing will work - it's just a case of which side
you want the return tube to run through the firewall and up to the tank.
Daniel Sasseville (eastern Canada Rotax rep) suggested that you run it
into
the top of the tank at the front - probably beside the site tube outlet.

Sounds like you're getting there. I also recommend Daniel's mount for the
912 as we moved the engine 3 inches further out from the firewall which
resulted in a good C of G, good baggage allowance, and I feel - a good
balanced "look".

Here's his link - just in case.
http://www.rotaxservice.com/about/index.htm

Cheers
Jim #333




On 9/17/2007 6:01 PM, "Charlie Eubanks" <charlie@troyairpark.com> wrote:

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

Hi Wayne, welcome back.

I have one here you can look at any time. I'm not an engineer but just
followed instructions for my installation. Page 9-2 on this pdf explains
that the return line is there to avoid vapour lock.

http://www.rotax-aircraft-engines.com/p ... d03486.pdf


Cheers
Jim


On 9/26/2007 6:16 PM, "Wayne G. O'Shea" <oifa@irishfield.on.ca> wrote:

I would like to know more about this return line as well.....I have never
seen a 912UL or 912ULS with a fuel return line.

Wayne

----- Original Message -----
From: "Ken" <klehman@albedo.net>
To: <rebel-builders@dcsol.com>
Sent: Tuesday, September 18, 2007 8:43 AM
Subject: [rebel-builders] rotax fuel return

Hmmm - Maybe he wants the return to the top of the tank so that fuel
can't reverse flow from the tank to the engine in case of a leak or
fire...
Just a guess and could be totally wrong.

Guys have pumped all the fuel from one tank through the return to the
other tank and overboard with poorly designed soob systems but those use
a high pressure fuel pump and return a lot more fuel.

Ken

Jim Cole wrote:



-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------