The Murphy Builders Site

I've been in strong rain for ~ 30 min several times. No water in my tanks
ever. I have seen water in tanks in another Super Rebel in Alaska though--I
assume that was from condensation, but don't know that for sure.

Ted

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Walter
Klatt
Sent: Tuesday, January 31, 2012 5:01 PM
To: rebel-builders@dcsol.com
Subject: RE: (SPAM?) Re: [rebel-builders] Fuel ports into cabin

I've yet to ever find any water in any of my tanks, lines or gascolator. And
I have flown in a few pretty strong rain storms. I have the ram vents in my
fuel caps. So if water does get in there, can't be a lot, and don't know
where it disappears to if I do get any.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Paul
Lennemann
Sent: Tuesday, January 31, 2012 3:43 PM
To: rebel-builders@dcsol.com
Subject: re: (SPAM?) Re: [rebel-builders] Fuel ports into cabin

Does water enter the fuel tanks when flying in the rain?

Paul Lennemann

----------------------------------------

From: "Ken" <klehman@albedo.net>
Sent: Tuesday, January 31, 2012 2:53 PM
To: rebel-builders@dcsol.com
Subject: (SPAM?) Re: [rebel-builders] Fuel ports into cabin

No impact on the automotive EFI systems that I'm familiar with but ram
pressure may help prevent cavitation depending on any plumbing to the pump.
Others have observed that the ram air adds about 5 inches of head (makes the
tank seem 5" higher).

If this is automotive EFI injection, some 40 psi electric pumps don't like
slugs of air though and there is normally no reservoir like a carb float
bowel which means the engine will also immediately start missing if the pump
takes in a slug of air. I like some kind of header tank with EFI even if it
is only a pint or quart size.

My snorkel vent (inverted J at the wing root) is bent almost straight down
to slow the flow of air in through the crossvent and out MAM's tank caps. I
have no holes in the filler necks but my caps have small internal vents that
seem to let a fair bit of air flow out if the snorkel faces forward. A
richer mixture above the fuel is safer and I hate to waste fuel vapour or
vent that much pollution.

Ken

On 31/01/2012 2:35 PM, Wayne G. O'Shea wrote:

That's one for Ken ! But you need it vented no matter what or you'd
suck

you

tank flat!

----- Original Message -----
From: "Roland Kriening"
To:
Sent: Tuesday, January 31, 2012 2:24 PM
Subject: RE: [rebel-builders] Fuel ports into cabin

My guess is then that the ram air added + pressure would have no
impact

on

the fuel injection system, but just vent the tank ( and keep the fuel

in

the
tank ). Thinking out loud ??

Roland


-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of
Wayne G. O'Shea
Sent: Tuesday, January 31, 2012 11:15 AM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Fuel ports into cabin

The issue with "store bought" snorkel caps... they are usually
already bent and since>you< placed, drilled and riveted the filler
neck in place it probably won't match the correct locking direction
for the cap. They're fine

if you have the caps prior to building so you can orient the filler

neck,

or

willing to try to straighten .. then rebend the ram air tube. The
other issue with them.... don't let the lad at the airport fuel your

airplane!

They always think they look neater with the tube facing BACKWARDS !

Yes.. it faces forward and creates a small + pressure which helps
keep fuel flow even in both wings and more importantly forces it down
the line to the carburetor. Snorkel scoops are mandatory on a few
SCub STC's for more horsepower = making sure the fuel is being
delivered.

I don't like them on the caps.. although it is an easier and more

likely

place that they'll get checked for being open / clear of bugs. I
prefer

to

tee the cross over line and pop a tube up thru the wing root fairing

and

bend forward into the air stream. Small piece of brass screen
inserted

to

keep the mud dabbers out.

Wayne

----- Original Message -----
From: "Roland Kriening"
To:
Sent: Tuesday, January 31, 2012 7:23 AM
Subject: RE: [rebel-builders] Fuel ports into cabin

Great, I am going to print and save these instructions. A newbie
question...
does one buy the ram air tube or make one. I have seen them on top
of

gas

caps but assume they have been welded on. So just so I understand,
the ram air tube does need to come up into the airstream. Can I
assume then

that

the
pressure created by the airstream keeps the fuel from escaping
during

a

turn. My education continues.

Drew, if you have a pic or two it would really help.

Roland
R56

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf
Of Drew Dalgleish
Sent: Monday, January 30, 2012 10:00 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Fuel ports into cabin

Hi Roland I should expand my answer. I recall you have an early
serial number and not sure which manual you're working from. It was

discovered

the hard way that under some circumstances fuel may siphon from one

tank

to the other and overboard through the vent hole in the filler neck.

So

to break any chance for a siphon a cross vent is installed between
the

2

tanks. There's a service bulletin covering this. What I have done on
Wayne's advice is install a ram air tube in that vent line and block

the

vents on the filler neck. I installed a tee in the vent line between

the

wing and the fuselage With one side sticking straight up. The ram
air tube goes up through the wing root fairing and curves forward
into the airstream. I only installed one vent but many others
including Wayne (

I

think ) have put one on each side. There's also a lot of builders
that have installed ram air tubes in their gas caps. I'm sure that
either solution will work equally well to slightly pressurize the tanks.

On 30/01/2012 5:58 PM, Roland Kriening wrote:

I

am

you

have

hole

for

this

before

connect

it

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