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Old Oct 21, 2008, 09:49 AM
dan
Guest
n/a Posts
fuel tank size

i'm planing to use os 120 engine on a new model and want to use a big
fuel tank in order to get a long flight time (about 1000 cc).
I read in the past that there is a limited size for the tank, and you
cant use a big size tank.
in the manual of the engine the recomended size is about 350cc.
is it a problem to use bigger tank?
and if yes is there a way to do it?
dan
Old Oct 21, 2008, 11:02 AM
Robert Roland
Guest
n/a Posts
Re: fuel tank size

On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danimaoz@gmail.com>
wrote:

>is it a problem to use bigger tank?


I have a Telemaster with an OS 1.08 and a 1000cc tank. No problems
whatsoever. The Telemaster can carry a lot of payload and is not very
sensitive to CG location, so the weight is not a problem either.

If I fly a lot at full power, such as when lifting gliders, I get
about half an hour on a tankful.
--
RoRo
Old Oct 21, 2008, 11:38 AM
Martin X. Moleski, SJ
Guest
n/a Posts
Re: fuel tank size

On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danimaoz@gmail.com> wrote in
<94b53f65-6e23-4597-8616-33a5cd354c70@d31g2000hsg.googlegroups.com>:

>i'm planing to use os 120 engine on a new model and want to use a big
>fuel tank in order to get a long flight time (about 1000 cc).
>I read in the past that there is a limited size for the tank, and you
>cant use a big size tank.
>in the manual of the engine the recomended size is about 350cc.
>is it a problem to use bigger tank?
>and if yes is there a way to do it?


In my view, the best thing to do is to just try
the tank size you want and see what happens.

The issue is probably fuel draw.

You will also have a very large shift of CG
as you drain the tank if you locate it off
the CG of the plane. If the tank is forward,
the plane will be nose-heavy at takeoff less
so when the tank is empty.

You can get various pumps or fuel regulators
to help with the draw. I've heard good things
about Perry pumps and Kline regulators but
haven't used either myself.

Another potential problem: inconsistency during
the run. The big tank may produce extra pressure
when full. I usually try to get the centerline
of my tanks at or just below the position of the
spraybar in the carb. With an oversize tank,
you may have to run overly rich at first in order
not to run too lean later in the flight.

My guess is that you can probably solve all these
problems ...

Good luck with your project. Let us know how it
turns out.

Marty
--
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Old Oct 24, 2008, 11:46 AM
Ed Cregger
Guest
n/a Posts
Re: fuel tank size


"Martin X. Moleski, SJ" <moleski@canisius.edu> wrote in message
news:Jdedna3LoNTzmGPVnZ2dnUVZ_gOdnZ2d@supernews.co m...
> On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danimaoz@gmail.com> wrote
> in
> <94b53f65-6e23-4597-8616-33a5cd354c70@d31g2000hsg.googlegroups.com>:
>
>>i'm planing to use os 120 engine on a new model and want to use a big
>>fuel tank in order to get a long flight time (about 1000 cc).
>>I read in the past that there is a limited size for the tank, and you
>>cant use a big size tank.
>>in the manual of the engine the recomended size is about 350cc.
>>is it a problem to use bigger tank?
>>and if yes is there a way to do it?

>
> In my view, the best thing to do is to just try
> the tank size you want and see what happens.
>
> The issue is probably fuel draw.
>
> You will also have a very large shift of CG
> as you drain the tank if you locate it off
> the CG of the plane. If the tank is forward,
> the plane will be nose-heavy at takeoff less
> so when the tank is empty.
>
> You can get various pumps or fuel regulators
> to help with the draw. I've heard good things
> about Perry pumps and Kline regulators but
> haven't used either myself.
>
> Another potential problem: inconsistency during
> the run. The big tank may produce extra pressure
> when full. I usually try to get the centerline
> of my tanks at or just below the position of the
> spraybar in the carb. With an oversize tank,
> you may have to run overly rich at first in order
> not to run too lean later in the flight.
>
> My guess is that you can probably solve all these
> problems ...
>
> Good luck with your project. Let us know how it
> turns out.
>
> Marty


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

As Marty has indicated, the fuel pressure head will vary during your flight
and change your mixture as the engine consumes the fuel. This is not good
because as the fuel is burned off, the fuel to air ratio seen by your engine
becomes leaner and leaner.

There are three solutions to this problem.

The first is to buy an engine with a pressurized fuel system installed by
the factory, such as a YS or an OS FS-120 Surpass III/Pump.

The second solution is to buy a third party pump/regulator such as the Perry
system. The Perry system is a pump that relies upon crankcase impulse
pressure gained from the engine's lower crankcase area (two-stroke). This
can also be made to work with a four-stroke if you look for the information
here on RCU.

The third option is to go with a Cline Regulator. The Cline Regulator
requires that the tank be pressurized over atmospheric level. This is easily
accomplished by running a pressure line from the muffler to the fuel tank
vent line. This choice is my favorite of the three. It is the simplest. It
is effective. It is relatively inexpensive to accomplish ($60 USD, plus
shipping) and it works with no known disadvantages when compared to the
other two methods.

With all three of the choices listed above, it is feasible to mount the fuel
tank near the balance point of the model (CG), so as not to suffer a severe
trim change as the fuel burns off. Good luck.

Ed Cregger


Old Oct 24, 2008, 02:07 PM
Anyolmouse
Guest
n/a Posts
Re: fuel tank size


"Ed Cregger" <ecregger@bellsouff.net> wrote in message
news:1VmMk.50792$XT1.24778@bignews5.bellsouth.net. ..
|
| "Martin X. Moleski, SJ" <moleski@canisius.edu> wrote in message
| news:Jdedna3LoNTzmGPVnZ2dnUVZ_gOdnZ2d@supernews.co m...
| > On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danimaoz@gmail.com>
wrote
| > in
| > <94b53f65-6e23-4597-8616-33a5cd354c70@d31g2000hsg.googlegroups.com>:
| >
| >>i'm planing to use os 120 engine on a new model and want to use a
big
| >>fuel tank in order to get a long flight time (about 1000 cc).
| >>I read in the past that there is a limited size for the tank, and
you
| >>cant use a big size tank.
| >>in the manual of the engine the recomended size is about 350cc.
| >>is it a problem to use bigger tank?
| >>and if yes is there a way to do it?
| >
| > In my view, the best thing to do is to just try
| > the tank size you want and see what happens.
| >
| > The issue is probably fuel draw.
| >
| > You will also have a very large shift of CG
| > as you drain the tank if you locate it off
| > the CG of the plane. If the tank is forward,
| > the plane will be nose-heavy at takeoff less
| > so when the tank is empty.
| >
| > You can get various pumps or fuel regulators
| > to help with the draw. I've heard good things
| > about Perry pumps and Kline regulators but
| > haven't used either myself.
| >
| > Another potential problem: inconsistency during
| > the run. The big tank may produce extra pressure
| > when full. I usually try to get the centerline
| > of my tanks at or just below the position of the
| > spraybar in the carb. With an oversize tank,
| > you may have to run overly rich at first in order
| > not to run too lean later in the flight.
| >
| > My guess is that you can probably solve all these
| > problems ...
| >
| > Good luck with your project. Let us know how it
| > turns out.
| >
| > Marty
|
| ---------------
|
| As Marty has indicated, the fuel pressure head will vary during your
flight
| and change your mixture as the engine consumes the fuel. This is not
good
| because as the fuel is burned off, the fuel to air ratio seen by your
engine
| becomes leaner and leaner.
|
| There are three solutions to this problem.
|
| The first is to buy an engine with a pressurized fuel system installed
by
| the factory, such as a YS or an OS FS-120 Surpass III/Pump.
|
| The second solution is to buy a third party pump/regulator such as the
Perry
| system. The Perry system is a pump that relies upon crankcase impulse
| pressure gained from the engine's lower crankcase area (two-stroke).
This
| can also be made to work with a four-stroke if you look for the
information
| here on RCU.
|
| The third option is to go with a Cline Regulator. The Cline Regulator
| requires that the tank be pressurized over atmospheric level. This is
easily
| accomplished by running a pressure line from the muffler to the fuel
tank
| vent line. This choice is my favorite of the three. It is the
simplest. It
| is effective. It is relatively inexpensive to accomplish ($60 USD,
plus
| shipping) and it works with no known disadvantages when compared to
the
| other two methods.
|
| With all three of the choices listed above, it is feasible to mount
the fuel
| tank near the balance point of the model (CG), so as not to suffer a
severe
| trim change as the fuel burns off. Good luck.
|
| Ed Cregger


Excuse me for breaking in here but there are more options. Varsane
(Perry) makes a vibration operated pump that they recommend for 4
strokes. Here is a Saito link that covers the options for their engines
which would apply for other non pumped engines as well.
http://saito-engines.info/pumps.html

I have used the VP-30 (red body) for mounting the tank over 6 inches
behind the engine on an OS BGX3500 with good results and used them with
Fox engines routinely because of fuel draw problems due to their large
venturi opening.

--
Anyolmouse


Old Oct 24, 2008, 06:31 PM
dan
Guest
n/a Posts
Re: fuel tank size

On Oct 24, 6:46=A0pm, "Ed Cregger" <ecreg...@bellsouff.net> wrote:
> "Martin X. Moleski, SJ" <mole...@canisius.edu> wrote in messagenews:Jdedn=

a3LoNTzmGPVnZ2dnUVZ_gOdnZ2d@supernews.com...
>
>
>
>
>
> > On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danim...@gmail.com> wrot=

e
> > in
> > <94b53f65-6e23-4597-8616-33a5cd354...@d31g2000hsg.googlegroups.com>:

>
> >>i'm planing to use os 120 engine on a new model and want to use a big
> >>fuel tank in order to get a long flight time (about 1000 cc).
> >>I read in the past that there is a limited size for the tank, and you
> >>cant use a big size tank.
> >>in the manual of the engine the recomended size is about 350cc.
> >>is it a problem to use bigger tank?
> >>and if yes is there a way to do it?

>
> > In my view, the best thing to do is to just try
> > the tank size you want and see what happens.

>
> > The issue is probably fuel draw.

>
> > You will also have a very large shift of CG
> > as you drain the tank if you locate it off
> > the CG of the plane. =A0If the tank is forward,
> > the plane will be nose-heavy at takeoff less
> > so when the tank is empty.

>
> > You can get various pumps or fuel regulators
> > to help with the draw. =A0I've heard good things
> > about Perry pumps and Kline regulators but
> > haven't used either myself.

>
> > Another potential problem: inconsistency during
> > the run. =A0The big tank may produce extra pressure
> > when full. =A0I usually try to get the centerline
> > of my tanks at or just below the position of the
> > spraybar in the carb. =A0With an oversize tank,
> > you may have to run overly rich at first in order
> > not to run too lean later in the flight.

>
> > My guess is that you can probably solve all these
> > problems ...

>
> > Good luck with your project. =A0Let us know how it
> > turns out.

>
> > Marty

>
> ---------------
>
> As Marty has indicated, the fuel pressure head will vary during your flig=

ht
> and change your mixture as the engine consumes the fuel. This is not good
> because as the fuel is burned off, the fuel to air ratio seen by your eng=

ine
> becomes leaner and leaner.
>
> There are three solutions to this problem.
>
> The first is to buy an engine with a pressurized fuel system installed by
> the factory, such as a YS or an OS FS-120 Surpass III/Pump.
>
> The second solution is to buy a third party pump/regulator such as the Pe=

rry
> system. The Perry system is a pump that relies upon crankcase impulse
> pressure gained from the engine's lower crankcase area (two-stroke). This
> can also be made to work with a four-stroke if you look for the informati=

on
> here on RCU.
>
> The third option is to go with a Cline Regulator. The Cline Regulator
> requires that the tank be pressurized over atmospheric level. This is eas=

ily
> accomplished by running a pressure line from the muffler to the fuel tank
> vent line. This choice is my favorite of the three. It is the simplest. I=

t
> is effective. It is relatively inexpensive to accomplish ($60 USD, plus
> shipping) and it works with no known disadvantages when compared to the
> other two methods.
>
> With all three of the choices listed above, it is feasible to mount the f=

uel
> tank near the balance point of the model (CG), so as not to suffer a seve=

re
> trim change as the fuel burns off. Good luck.
>
> Ed Cregger- Hide quoted text -
>
> - Show quoted text -


Tnx for the information
about the cline regulator.....
i'm going to use a 2 cycle engine,
from the article i read in the internet in 2 cycle engines the
pressure comes from the cranck case, that to my understanding means to
drill a hole in the engins case. can i connect the pressure to the
mufller's regular pressure conection? while using the cline reg with 2
cycle engine?
Tnx
Old Oct 24, 2008, 06:48 PM
Martin X. Moleski, SJ
Guest
n/a Posts
Re: fuel tank size

On Fri, 24 Oct 2008 16:31:49 -0700 (PDT), dan <danimaoz@gmail.com> wrote in
<b1ee1ee5-1078-4bb2-9c0b-4ca0d207a78e@u75g2000hsf.googlegroups.com>:


>about the cline regulator.....


>i'm going to use a 2 cycle engine,


>from the article i read in the internet in 2 cycle engines the
>pressure comes from the cranck case, that to my understanding means to
>drill a hole in the engins case. can i connect the pressure to the
>mufller's regular pressure conection? while using the cline reg with 2
>cycle engine?


The Cline system requires no drilling.

All of the contemporary 2-cycle designs get pressure from
the muffler-tap. I haven't heard of any tapless muffler
in years and years.

The Cline system gets pressure from the muffler tap
and keeps the pressure high in the tank by the use
of a check valve (that may be the weak link in the Cline
system). Then the regulator is placed in the fuel line
near the needle valve (within 1" or so, if I remember
correctly). When the regulator "feels" suction from
the fuel line, it lets a dose of fuel through; when
the suction stops, so does the flow of fuel.

Some of the pumps do get pressure from drilling holes
in the crankcase. Those are different from the Cline
system.

It sounds as though you haven't done any RC yet. You
might want to go with a smaller, simpler rig until you
get up to speed on how things work.

Marty
--
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See http://www.big-8.org for info on how to add or remove newsgroups.
Old Oct 24, 2008, 10:55 PM
dan
Guest
n/a Posts
Re: fuel tank size

On Oct 24, 9:07=A0pm, "Anyolmouse" <Anyolmo...@invalid.invalid> wrote:
> "Ed Cregger" <ecreg...@bellsouff.net> wrote in message
>
> news:1VmMk.50792$XT1.24778@bignews5.bellsouth.net. ..
> |
> | "Martin X. Moleski, SJ" <mole...@canisius.edu> wrote in message
> |news:Jdedna3LoNTzmGPVnZ2dnUVZ_gOdnZ2d@supernews.c om...
> | > On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danim...@gmail.com>
> wrote
> | > in
> | > <94b53f65-6e23-4597-8616-33a5cd354...@d31g2000hsg.googlegroups.com>:
> | >
> | >>i'm planing to use os 120 engine on a new model and want to use a
> big
> | >>fuel tank in order to get a long flight time (about 1000 cc).
> | >>I read in the past that there is a limited size for the tank, and
> you
> | >>cant use a big size tank.
> | >>in the manual of the engine the recomended size is about 350cc.
> | >>is it a problem to use bigger tank?
> | >>and if yes is there a way to do it?
> | >
> | > In my view, the best thing to do is to just try
> | > the tank size you want and see what happens.
> | >
> | > The issue is probably fuel draw.
> | >
> | > You will also have a very large shift of CG
> | > as you drain the tank if you locate it off
> | > the CG of the plane. =A0If the tank is forward,
> | > the plane will be nose-heavy at takeoff less
> | > so when the tank is empty.
> | >
> | > You can get various pumps or fuel regulators
> | > to help with the draw. =A0I've heard good things
> | > about Perry pumps and Kline regulators but
> | > haven't used either myself.
> | >
> | > Another potential problem: inconsistency during
> | > the run. =A0The big tank may produce extra pressure
> | > when full. =A0I usually try to get the centerline
> | > of my tanks at or just below the position of the
> | > spraybar in the carb. =A0With an oversize tank,
> | > you may have to run overly rich at first in order
> | > not to run too lean later in the flight.
> | >
> | > My guess is that you can probably solve all these
> | > problems ...
> | >
> | > Good luck with your project. =A0Let us know how it
> | > turns out.
> | >
> | > Marty
> |
> | ---------------
> |
> | As Marty has indicated, the fuel pressure head will vary during your
> flight
> | and change your mixture as the engine consumes the fuel. This is not
> good
> | because as the fuel is burned off, the fuel to air ratio seen by your
> engine
> | becomes leaner and leaner.
> |
> | There are three solutions to this problem.
> |
> | The first is to buy an engine with a pressurized fuel system installed
> by
> | the factory, such as a YS or an OS FS-120 Surpass III/Pump.
> |
> | The second solution is to buy a third party pump/regulator such as the
> Perry
> | system. The Perry system is a pump that relies upon crankcase impulse
> | pressure gained from the engine's lower crankcase area (two-stroke).
> This
> | can also be made to work with a four-stroke if you look for the
> information
> | here on RCU.
> |
> | The third option is to go with a Cline Regulator. The Cline Regulator
> | requires that the tank be pressurized over atmospheric level. This is
> easily
> | accomplished by running a pressure line from the muffler to the fuel
> tank
> | vent line. This choice is my favorite of the three. It is the
> simplest. It
> | is effective. It is relatively inexpensive to accomplish ($60 USD,
> plus
> | shipping) and it works with no known disadvantages when compared to
> the
> | other two methods.
> |
> | With all three of the choices listed above, it is feasible to mount
> the fuel
> | tank near the balance point of the model (CG), so as not to suffer a
> severe
> | trim change as the fuel burns off. Good luck.
> |
> | Ed Cregger
>
> Excuse me for breaking in here but there are more options. Varsane
> (Perry) makes a vibration operated pump that they recommend for 4
> strokes. Here is a Saito link that covers the options for their engines
> which would apply for other non pumped engines as well.http://saito-engin=

es.info/pumps.html
>
> I have used the VP-30 (red body) for mounting the tank over 6 inches
> behind the engine on an OS BGX3500 with good results and used them with
> Fox engines routinely because of fuel draw problems due to their large
> venturi opening.
>
> --
> Anyolmouse


Tnx for the information
after reading in the internet about the Cline Regulator iunderstood
that using it with 2 cycle engines means to get pressure from the
cranck case. is it correct?
can i use the regukar pressure from the muffler??
Old Oct 24, 2008, 11:23 PM
Martin X. Moleski, SJ
Guest
n/a Posts
Re: fuel tank size

On Fri, 24 Oct 2008 20:55:31 -0700 (PDT), dan <danimaoz@gmail.com> wrote in
<d7413621-e57b-4f4f-aa01-4357e0b0a4ab@e17g2000hsg.googlegroups.com>:

>Tnx for the information
>after reading in the internet about the Cline Regulator iunderstood
>that using it with 2 cycle engines means to get pressure from the
>cranck case. is it correct?


>can i use the regukar pressure from the muffler??


According to the Cline website, they recommend
crankcase pressure for 2-cycles and muffler pressure
for 4-cycles:

http://www.billsroom.com/pcfs/produc...fs_install.htm

Marty
--
Big-8 newsgroups: humanities.*, misc.*, news.*, rec.*, sci.*, soc.*, talk.*
See http://www.big-8.org for info on how to add or remove newsgroups.
Old Oct 25, 2008, 08:34 AM
Anyolmouse
Guest
n/a Posts
Re: fuel tank size


"dan" <danimaoz@gmail.com> wrote in message
news:d7413621-e57b-4f4f-aa01-4357e0b0a4ab@e17g2000hsg.googlegroups.com...
On Oct 24, 9:07 pm, "Anyolmouse" <Anyolmo...@invalid.invalid> wrote:
> "Ed Cregger" <ecreg...@bellsouff.net> wrote in message
>
> news:1VmMk.50792$XT1.24778@bignews5.bellsouth.net. ..
> |
> | "Martin X. Moleski, SJ" <mole...@canisius.edu> wrote in message
> |news:Jdedna3LoNTzmGPVnZ2dnUVZ_gOdnZ2d@supernews.c om...
> | > On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danim...@gmail.com>
> wrote
> | > in
> | >

<94b53f65-6e23-4597-8616-33a5cd354...@d31g2000hsg.googlegroups.com>:
> | >
> | >>i'm planing to use os 120 engine on a new model and want to use a
> big
> | >>fuel tank in order to get a long flight time (about 1000 cc).
> | >>I read in the past that there is a limited size for the tank, and
> you
> | >>cant use a big size tank.
> | >>in the manual of the engine the recomended size is about 350cc.
> | >>is it a problem to use bigger tank?
> | >>and if yes is there a way to do it?
> | >
> | > In my view, the best thing to do is to just try
> | > the tank size you want and see what happens.
> | >
> | > The issue is probably fuel draw.
> | >
> | > You will also have a very large shift of CG
> | > as you drain the tank if you locate it off
> | > the CG of the plane. If the tank is forward,
> | > the plane will be nose-heavy at takeoff less
> | > so when the tank is empty.
> | >
> | > You can get various pumps or fuel regulators
> | > to help with the draw. I've heard good things
> | > about Perry pumps and Kline regulators but
> | > haven't used either myself.
> | >
> | > Another potential problem: inconsistency during
> | > the run. The big tank may produce extra pressure
> | > when full. I usually try to get the centerline
> | > of my tanks at or just below the position of the
> | > spraybar in the carb. With an oversize tank,
> | > you may have to run overly rich at first in order
> | > not to run too lean later in the flight.
> | >
> | > My guess is that you can probably solve all these
> | > problems ...
> | >
> | > Good luck with your project. Let us know how it
> | > turns out.
> | >
> | > Marty
> |
> | ---------------
> |
> | As Marty has indicated, the fuel pressure head will vary during your
> flight
> | and change your mixture as the engine consumes the fuel. This is not
> good
> | because as the fuel is burned off, the fuel to air ratio seen by

your
> engine
> | becomes leaner and leaner.
> |
> | There are three solutions to this problem.
> |
> | The first is to buy an engine with a pressurized fuel system

installed
> by
> | the factory, such as a YS or an OS FS-120 Surpass III/Pump.
> |
> | The second solution is to buy a third party pump/regulator such as

the
> Perry
> | system. The Perry system is a pump that relies upon crankcase

impulse
> | pressure gained from the engine's lower crankcase area (two-stroke).
> This
> | can also be made to work with a four-stroke if you look for the
> information
> | here on RCU.
> |
> | The third option is to go with a Cline Regulator. The Cline

Regulator
> | requires that the tank be pressurized over atmospheric level. This

is
> easily
> | accomplished by running a pressure line from the muffler to the fuel
> tank
> | vent line. This choice is my favorite of the three. It is the
> simplest. It
> | is effective. It is relatively inexpensive to accomplish ($60 USD,
> plus
> | shipping) and it works with no known disadvantages when compared to
> the
> | other two methods.
> |
> | With all three of the choices listed above, it is feasible to mount
> the fuel
> | tank near the balance point of the model (CG), so as not to suffer a
> severe
> | trim change as the fuel burns off. Good luck.
> |
> | Ed Cregger
>
> Excuse me for breaking in here but there are more options. Varsane
> (Perry) makes a vibration operated pump that they recommend for 4
> strokes. Here is a Saito link that covers the options for their

engines
> which would apply for other non pumped engines as

well.http://saito-engines.info/pumps.html
>
> I have used the VP-30 (red body) for mounting the tank over 6 inches
> behind the engine on an OS BGX3500 with good results and used them

with
> Fox engines routinely because of fuel draw problems due to their large
> venturi opening.
>
> --
> Anyolmouse


Tnx for the information
after reading in the internet about the Cline Regulator iunderstood
that using it with 2 cycle engines means to get pressure from the
cranck case. is it correct?
can i use the regukar pressure from the muffler??

You pressure your tank with crankcase pressure when using it on a 2
cycle engine and you must use exhaust pressure when you use it on a 4
cycle engine. The Cline is a REGULATOR. It is not a pump. It uses a
check valve to hold pressure in the tank and then it regulates a
constant pressure to the engines needle valve.

Did you follow the link to Cline?
http://www.billsroom.com/pcfs/produc...uelsysdesc.htm The
instructions are here:
http://www.billsroom.com/pcfs/produc...fs_install.htm If you click
on the box marked schematic for one tank-one engine that is on the right
side of the screen it will show you exactly how to hook it up. The tees
shown for venting and filling MUST be stopped up after filling the tank
for the system to work properly.

A minus for the Cline system is that the system is pressurized at least
2lb/sq in which requires very secure fuel line connections. Some of the
guys I knew that were using the system wrapped their tanks with nylon
stranded packing tape to control tank expansion.

All of the above is why I decided to use the Perry pump system. It will
draw fuel up to 9 inches away from the pump using crankcase pressure
only. While I haven't tried it, others have used exhaust pressure in
conjunction with the pump for greater pump to tank distances.

--
Anyolmouse

Old Oct 25, 2008, 09:08 AM
Martin X. Moleski, SJ
Guest
n/a Posts
Re: fuel tank size

On Sat, 25 Oct 2008 08:34:54 -0500, "Anyolmouse" <Anyolmouse@invalid.invalid> wrote in <mgFMk.11747$ys6.6834@newsfe02.iad>:

>Did you follow the link to Cline?


>http://www.billsroom.com/pcfs/produc...uelsysdesc.htm


>The
>instructions are here:
>http://www.billsroom.com/pcfs/produc...fs_install.htm


>If you click
>on the box marked schematic for one tank-one engine that is on the right
>side of the screen it will show you exactly how to hook it up. The tees
>shown for venting and filling MUST be stopped up after filling the tank
>for the system to work properly.


>A minus for the Cline system is that the system is pressurized at least
>2lb/sq in which requires very secure fuel line connections. Some of the
>guys I knew that were using the system wrapped their tanks with nylon
>stranded packing tape to control tank expansion.


I think the pattern guys often do that when setting up YS systems, too.

The trouble with expansion is that a tank can split along the
seams after it's gone through enough cycles.

>All of the above is why I decided to use the Perry pump system. It will
>draw fuel up to 9 inches away from the pump using crankcase pressure
>only. While I haven't tried it, others have used exhaust pressure in
>conjunction with the pump for greater pump to tank distances.


Marty
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Old Oct 26, 2008, 11:56 PM
dan
Guest
n/a Posts
Re: fuel tank size

On Oct 25, 3:34=A0pm, "Anyolmouse" <Anyolmo...@invalid.invalid> wrote:
> "dan" <danim...@gmail.com> wrote in message
>
> news:d7413621-e57b-4f4f-aa01-4357e0b0a4ab@e17g2000hsg.googlegroups.com...
> On Oct 24, 9:07 pm, "Anyolmouse" <Anyolmo...@invalid.invalid> wrote:> "Ed=

Cregger" <ecreg...@bellsouff.net> wrote in message
>
> >news:1VmMk.50792$XT1.24778@bignews5.bellsouth.net ...
> > |
> > | "Martin X. Moleski, SJ" <mole...@canisius.edu> wrote in message
> > |news:Jdedna3LoNTzmGPVnZ2dnUVZ_gOdnZ2d@supernews.c om...
> > | > On Tue, 21 Oct 2008 07:49:17 -0700 (PDT), dan <danim...@gmail.com>
> > wrote
> > | > in
> > | >

>
> <94b53f65-6e23-4597-8616-33a5cd354...@d31g2000hsg.googlegroups.com>:
>
>
>
> > | >
> > | >>i'm planing to use os 120 engine on a new model and want to use a
> > big
> > | >>fuel tank in order to get a long flight time (about 1000 cc).
> > | >>I read in the past that there is a limited size for the tank, and
> > you
> > | >>cant use a big size tank.
> > | >>in the manual of the engine the recomended size is about 350cc.
> > | >>is it a problem to use bigger tank?
> > | >>and if yes is there a way to do it?
> > | >
> > | > In my view, the best thing to do is to just try
> > | > the tank size you want and see what happens.
> > | >
> > | > The issue is probably fuel draw.
> > | >
> > | > You will also have a very large shift of CG
> > | > as you drain the tank if you locate it off
> > | > the CG of the plane. If the tank is forward,
> > | > the plane will be nose-heavy at takeoff less
> > | > so when the tank is empty.
> > | >
> > | > You can get various pumps or fuel regulators
> > | > to help with the draw. I've heard good things
> > | > about Perry pumps and Kline regulators but
> > | > haven't used either myself.
> > | >
> > | > Another potential problem: inconsistency during
> > | > the run. The big tank may produce extra pressure
> > | > when full. I usually try to get the centerline
> > | > of my tanks at or just below the position of the
> > | > spraybar in the carb. With an oversize tank,
> > | > you may have to run overly rich at first in order
> > | > not to run too lean later in the flight.
> > | >
> > | > My guess is that you can probably solve all these
> > | > problems ...
> > | >
> > | > Good luck with your project. Let us know how it
> > | > turns out.
> > | >
> > | > Marty
> > |
> > | ---------------
> > |
> > | As Marty has indicated, the fuel pressure head will vary during your
> > flight
> > | and change your mixture as the engine consumes the fuel. This is not
> > good
> > | because as the fuel is burned off, the fuel to air ratio seen by

> your
> > engine
> > | becomes leaner and leaner.
> > |
> > | There are three solutions to this problem.
> > |
> > | The first is to buy an engine with a pressurized fuel system

> installed
> > by
> > | the factory, such as a YS or an OS FS-120 Surpass III/Pump.
> > |
> > | The second solution is to buy a third party pump/regulator such as

> the
> > Perry
> > | system. The Perry system is a pump that relies upon crankcase

> impulse
> > | pressure gained from the engine's lower crankcase area (two-stroke).
> > This
> > | can also be made to work with a four-stroke if you look for the
> > information
> > | here on RCU.
> > |
> > | The third option is to go with a Cline Regulator. The Cline

> Regulator
> > | requires that the tank be pressurized over atmospheric level. This

> is
> > easily
> > | accomplished by running a pressure line from the muffler to the fuel
> > tank
> > | vent line. This choice is my favorite of the three. It is the
> > simplest. It
> > | is effective. It is relatively inexpensive to accomplish ($60 USD,
> > plus
> > | shipping) and it works with no known disadvantages when compared to
> > the
> > | other two methods.
> > |
> > | With all three of the choices listed above, it is feasible to mount
> > the fuel
> > | tank near the balance point of the model (CG), so as not to suffer a
> > severe
> > | trim change as the fuel burns off. Good luck.
> > |
> > | Ed Cregger

>
> > Excuse me for breaking in here but there are more options. Varsane
> > (Perry) makes a vibration operated pump that they recommend for 4
> > strokes. Here is a Saito link that covers the options for their

> engines
> > which would apply for other non pumped engines as

>
> well.http://saito-engines.info/pumps.html
>
>
>
> > I have used the VP-30 (red body) for mounting the tank over 6 inches
> > behind the engine on an OS BGX3500 with good results and used them

> with
> > Fox engines routinely because of fuel draw problems due to their large
> > venturi opening.

>
> > --
> > Anyolmouse

>
> Tnx for the information
> after reading in the internet about the Cline Regulator iunderstood
> that using it with 2 cycle engines means to get pressure from the
> cranck case. is it correct?
> can i use the regukar pressure from the muffler??
>
> You pressure your tank with crankcase pressure when using it on a 2
> cycle engine and you must use exhaust pressure when you use it on a 4
> cycle engine. The Cline is a REGULATOR. It is not a pump. It uses a
> check valve to hold pressure in the tank and then it regulates a
> constant pressure to the engines needle valve.
>
> Did you follow the link to Cline?http://www.billsroom.com/pcfs/products/C=

FS/fuelsysdesc.htmThe
> instructions are here:http://www.billsroom.com/pcfs/products/CFS/pcfs_ins=

tall.htmIf you click
> on the box marked schematic for one tank-one engine that is on the right
> side of the screen it will show you exactly how to hook it up. The tees
> shown for venting and filling MUST be stopped up after filling the tank
> for the system to work properly.
>
> A minus for the Cline system is that the system is pressurized at least
> 2lb/sq in which requires very secure fuel line connections. Some of the
> guys I knew that were using the system wrapped their tanks with nylon
> stranded packing tape to control tank expansion.
>
> All of the above is why I decided to use the Perry pump system. It will
> draw fuel up to 9 inches away from the pump using crankcase pressure
> only. While I haven't tried it, others have used exhaust pressure in
> conjunction with the pump for greater pump to tank distances.
>
> --
> Anyolmouse- Hide quoted text -
>
> - Show quoted text -


Tnx for all the answers
and to marty, I'm an expirienced rc builder and flyer, but still
things that i don't know i prefer to ask, and ask again, instead of
doing things wrang
dani
 


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