full 46 (2 x23) US gallon tanks.
----- Original Message -----
From: "Jeff Micheal" <westcoastkitplanes@gmail.com>
To: <rebel-builders@dcsol.com>
Sent: Thursday, December 24, 2009 2:44 AM
Subject: Re: [rebel-builders] Fuel slector valves
Hey Keith,
Not to rain on your parade, but the 1st Rebel I built w/0320 could do over
8
hrs of flight (optional extended tanks). Just to go a little further, the
Rebel I flew back from Kingston, ON (Rotec R2800 equipped) also had over 8
hr of flight time with the standard 44 gal tanks (but you can squeeze more
in, if you try).
The only problem I had was trying to stay in the air for 8 hrs...........
after eating lunch on the fly.
Cheers,
Jeff
On Wed, Dec 23, 2009 at 11:07 PM, <kpierson@dcsol.com> wrote:
Ken:
You said that you have over 8 hr. of fuel, Do you have an extra
fuel tank? If so where do you have it? Or is it the header tank
that gives you the extra range? If so how big is it and where is
it? Or is your engine just that economical? I know, I know it's a
lot of questions!
Thank you
Keith P. 318R
On 12/23/2009 7:35 PM, klehman@albedo.net wrote to rebel-builders:
-> I too am a believer in a header tank. Solves the problem of air
bubbles
-> when low on fuel, in turbulence, or sideslipping. I put a float switch
-> in the header tank to tell me if it is not full. I do find that I have
-> started to keep more fuel in the right tank for balance. An aileron
trim
-> would probably be a better solution for me.
->
-> However when optimizing range or performance, one usually likes all
-> remaining fuel in one tank with an accurate quantity gauge so you have
-> confidence in how much is really there. Sometimes that avoids an extra
-> fuel stop for me. Kind of pointless having large tanks and carrying
-> extra fuel weight if you don't have confidence in how much is
useable.
-> I don't like guessing and my Rebel performs noticeably better when I
do
-> not carry excessive fuel. I have over 8 hours of fuel with full tanks.
-> In machines with multiple fuel tanks, it is not uncommon to watch a
fuel
-> pressure gauge for fluctuations and then switch tanks before the
engine
-> coughs. An amusing incidence of this (not in a Rebel) was accompanied
by
-> a major aircraft pitch up which quite surprised me. What happened was
-> that when the engine coughed a group of parachuters all immediately
-> moved to the rear door to get out... Imagine trusting silk more than
an
-> aircraft just because of a momentary hiccup ;)
->
-> I also recall an interesting night ferry trip on a newly purchased
-> aircraft. The destination had a curfew and the new owner was quite
-> nervous. It took me awhile to realize that he had previously rented
-> aircraft and had never actually flown with tanks less than half full.
->
-> I suspect that some specific Rebels may push air through the lines and
-> vent it through the carb float bowel. But many do not. One fellow used
-> transparent lines to prove that on his machine the air was being
trapped
-> at the top of the vertical line. The air would not travel the last few
-> inches of horizontal tube back into the wing tank. Air in the line
does
-> restrict fuel flow. He constructed a vapor separator at the top of the
-> vertical tubing to vent that air bubble. Fortunately when an engine
-> coughs, the first thing most pilots do is to switch on a tank that
they
-> are sure has fuel in it which I think avoids the problem being
discussed
-> below. With a header tank, I never give any of this a second thought.
->
-> Ken
->
->
-> Kevin & Nancy Mayville wrote:
-> > I am going to jump in here because I don't understand why any one
needs to
-> > drain one tank completely, I can understand burning one tank down to
say 3/4
-> > or so for balance, I would never run a tank down until the engine
coughs !
-> > I run both my tanks at the same time and I don't have any balance
problems
-> > with or without a passenger.
-> >
-> > My fuel system is a little different I have a ball valve at each aft
wing
-> > root ( which I can reach ) and then each tank flows in to a small
tank
like
-> > a header tank ( aprox 2''x3'' x 16'' long mounted vertically ) aft
of
the
-> > pilots seat. then the main shut off valve is just forward of the
pilots
door
-> > .
-> >
-> > This header tank eliminates any chance of air being trapped in the
fuel
-> > line. I believe this was the fix for the first generation of Glass
Stars
-> > because the fuel sloshed in the tanks and allowed air to block the
fuel
-> > lines like Walter stated, which caused some unscheduled landing .
-> >
-> > Kevin C-FRFP
-> >
-> >
-> > ----- Original Message -----
-> > From: "Walter Klatt" <Walter.Klatt@shaw.ca>
-> > To: <rebel-builders@dcsol.com>
-> > Sent: Tuesday, December 22, 2009 6:34 PM
-> > Subject: RE: [rebel-builders] Fuel slector valves
-> >
-> >
-> >> I am quite sure it will happen to any tank valve top mounted
gravity
feed
-> >> set up in a Rebel or Elite. I have my tanks cross vented, plus a
snorkel
-> >> vent on each cap.
-> >>
-> >> It has to do with trapped air in the lines below the valves. The
fuel
is
-> >> trying to flow down, while the air is trying to vent upwards to the
tanks,
-> >> which slows the fuel flow enough to stall the engine.
-> >>
-> >> Think about it. When you shut one tank off run to run the other one
dry,
-> >> all
-> >> the fuel will run out of both lines when the empty one finally
drains.
-> >> When
-> >> the engine runs out of fuel, there will be nothing but air left in
both
-> >> lines right up to the valves. Then if you close the empty tank
valve,
you
-> >> trap the air there. When you open the full one, the flow has to
fight
the
-> >> air coming up.
-> >>
-> >> If you keep the empty one open, the air has a place to get pushed
out
and
-> >> vented, and no problem.
-> >>
-> >> Again, if you use the right sequence, with opening and closing the
valves,
-> >> everything is fine. But with the wrong sequence, your engine will
quit,
-> >> and
-> >> you will not get it started in time before you hit the ground,
guaranteed.
-> >>
-> >> Trust me, I have been there, and I know this issue very, very well.
And
I
-> >> can replicate it on my plane on the ground any time, and I am sure
I
could
-> >> do it to yours if you have the same set up.
-> >>
-> >> Walter
-> >>
-> >> -----Original Message-----
-> >> From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf
Of Ron
-> >> Shannon
-> >> Sent: December 22, 2009 3:04 PM
-> >> To: rebel-builders@dcsol.com
-> >> Subject: Re: [rebel-builders] Fuel slector valves
-> >>
-> >> I believe the tank venting design will have an influence on this
switching
-> >> procedure. Not to reopen a subject that's been covered quite a bit
(see
-> >> archives) I think with dual vents and full cross vent (and perhaps
other
-> >> configurations) it may be possible to run one tank dry before
switching
as
-> >> Drew suggests -- if you're so inclined. Personally, I wouldn't
-> >> intentionally
-> >> cause an in flight shutdown except in an emergency scenario where
fuel
-> >> reserves absolutely had to be managed that tightly. Your mileage
may
-> >> vary --
-> >> literally. :-)
-> >>
-> >> Ron
-> >> 254R
-> >>
-> >>
-> >> On Tue, Dec 22, 2009 at 2:41 PM, Drew Dalgleish
-> >> <drewjan@cabletv.on.ca>wrote:
-> >>
-> >>> Hi Walter I wonder if that problem could be unique to your plane
cuz
I
-> >>> often run the pilots side tank empty to help balance my plane and
get
-> >>> maximum range. I think I usually turn off the empty tank before
turning
-> >>> on
-> >>> the one with fuel in it and I've never expreienced any delay in
the
-> >>> engine
-> >>> restarting.
-> >>> As for floor mounted valves consider where you place it so that if
you
-> >> ever
-> >>> install floats you will be able to easily crawl through to the
other
side
-> >>> for docking, pumping out, refueling etc.
-> >>>
-> >>> At 11:27 AM 22/12/2009 -0800, you wrote:
-> >>>> And with only the top mounted independent valves, be very careful
when
-> >>> running one tank dry while flying. The sequence for closing and
opening
-> >> the
-> >>> valves is very critical to avoid an air lock. I know this from
first
hand
-> >>> experience and am able to replicate the issue on the ground.
-> >>>> We've discussed it before on the list, but here is the sequence.
When
-> >>>> you
-> >>> run one tank dry, with the other full tank closed, you must first
open
-> >>> the
-> >>> full tank before you close the dry one. Otherwise, your engine
will
quit,
-> >>> and you will not be able to keep it running. It will restart, but
then
-> >> keep
-> >>> quitting on you.
-> >>>> The problem is that air gets trapped when you close the empty
one,
and
-> >> the
-> >>> full one can't flow fast enough. It flows just enough to start
your
-> >> engine,
-> >>> but it will keep quitting on you. If you keep the empty one open,
the
-> >>> locked air will vent up through it, and allow the good tank to
feed
down
-> >> to
-> >>> the carb. Once it is feeding OK, and the air is out, then you can
close
-> >> the
-> >>> empty one.
-> >>>> It took me a while to figure this out when it happened. Luckily,
I
was
-> >>>> on
-> >>> the ground when I first did it.
-> >>>> With floor mounted valves you avoid this problem, as the air
can't
get
-> >>> locked in the lines above to the tanks.
-> >>>> Walter
-> >>> Drew
-> >>>
-> >>
-----------------------------------------------------------------
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
-----------------------------------------------------------------
