| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 172.1 | PUMPS?.....ARRRRRRGH! | MAUDIB::CASEYA | THE DESERT RAT RC-AV8R | Fri Oct 02 1987 12:16 | 25 |
| Charlie,
Aha! You've thrown a "new" factor into the game; the pump. For
starters, I don't like pumps...as a matter of fact, I hate pumps!
I've yet to see one that actually "did" what it was claimed to with-
out "some" negative trade-off. Did the rough mid-range and fuel
consumption exist "before" you installed the pump? Think carefully
about this `cause one of the PRIMARY trade-offs of a pump in "higher
fuel consumption!" Also, many times a carb made specifically for
use with a pump MUST be used as the stock carb isn't "tight" enough
to handle the the higher volume/pressure fuel delivery. What happens
is that, at lower throttle settings (mid-range), the pump simply
delivers more fuel than the carb can effectively meter, so it runs
rich...you have a needle for high speed and idle but the mid-range
goes begging.
My advice, frankly, would be to simply sh**-can the pump! It's
just one more thing to go wrong (or to have to fiddle with) and
is absolutely unnecessary for just about all applications, save
for "ultra"- high performance (like racing) and, even then, most
often, only a tuned pipe is used. I (and just about every R/C'er
I know) have tried pumps, but NO ONE I know ever liked them or
continued to use them.
Please keep me updated as to yer' progress..., adios, Al
|
| 172.2 | "Inverted engine + fuel pump = ?????" | 37587::TULANKO | | Thu May 03 1990 10:27 | 34 |
|
From the looks of date of the last entry, its been
a few years since any questions were brought up on fuel pumps.
So with that , lets see what we can stir up in response( meaning
has Al and others changed their views on pumps due to newer
technology advances, if applicable ).
Here goes. I was wondering if the use of a fuel pump
would solve the problem with running an engine inverted . To
be more specific, would it aid in constant fuel flow since there
is no "ideal" location for an inverted engines fuel tank that
doesn't have its drawbacks (such as flooding at low idle while
comming in on a aproach or taxi). Also there's a problem with having
to pinch the fuel line to prevent carb flooding(actually when it's
inverted, fuel just kinda runs out the carb opening on to the
ground) . Is a fuel pumps valve "normally closed" when the engine
is not running ? If so , this would solve the 'hemostat to pinch
the fuel line' problem since the closed diaphram would inhibit fuel
flow to the carb.
So , what do ya say ? Are fuel pumps any better than
they were a few years ago ? If so, would it be better to buy
the internal pump for my OS SF.61 ABC to add on or buy an
external pump like a Perry ? I'm locked in on engine position
so side or upright mounting is not an option . If pumps still
are not very reliable , how about a fuel system like the Bryons
"Sure Flow" fuel tank system ? This looks like it could be a
possible solution . We're all ears !
Thanks,
Carl
|
| 172.3 | _______N_O_______!! | UPWARD::CASEYA | THE DESERT RAT (I-RC-AV8) | Thu May 03 1990 14:35 | 30 |
| Carl,
In a word (and, in my personal opinion), NO! Fuel pumps are just as
fidgety, fiddley, ornery as ever. A point in case is Charlie Chambers
crash of Contrary Mary (P-51) at Top Gun. He spent more than 2 1/2
days trying to get the pump set and it absolutely defied him (and many
other knowledgeable modelers) to get it set, the end result of which
was a crash that extensively damaged the wing and could easil have
totalled the magnificent model.
Pumps, again IMHO, are simply one more thing to go wrong and cause a
serious problem! There _IS_ an ideal tank location for inverted
engines: it should be as close to the engine as possible/practical and
the tank centerline should be 1/2" max lower than the needle-valve.
This helps to prevent siphoning or dumping fuel into the engine while
handling the model. Also, I recommend the Robart Super-fueler be used
as it shuts off flow to the engine while fueling. Additionally,
muffler pressure is a good bet; I'm pulling fuel more than 10" from my
clunk to the carb in the MiG-3 and it works great.
Nothing you might try will totally eliminate the eccentricities of
handling/starting an inverted engine but a simple starting routine,
practiced _every_ time will make it a painless matter to start and run
your inverted setup.
__
| | / |\
\|/ |______|__(o/--/ | \
| | 00 <| ~~~ ____ 04 ---- | --------------------
|_|_| (O>o |\)____/___|\_____|_/ Adios amigos, Al
| \__(O_\_ | |___/ o (The Desert Rat)
|
| 172.4 | ONE MORE THING..... | UPWARD::CASEYA | THE DESERT RAT (I-RC-AV8) | Thu May 03 1990 14:41 | 15 |
| Carl,
I meant to add that a fuel pump tends only to aggravate the flooding or
even liquid-locking problems resultant of getting too much fuel into
the inverted cylinder head. Consider that, through fueling or
whatever, the head's already a bit wet...now you start propping the
engine, the pump starts pumping and the problem has just been made even
worse. BTW, The Super-fueler I mentioned is by either Robart or DuBro
and maybe both.
__
| | / |\
\|/ |______|__(o/--/ | \
| | 00 <| ~~~ ____ 04 ---- | --------------------
|_|_| (O>o |\)____/___|\_____|_/ Adios amigos, Al
| \__(O_\_ | |___/ o (The Desert Rat)
|
| 172.5 | Check the tank..... | WHEY::SOUTIERE | | Thu May 03 1990 15:06 | 18 |
| Al, Carl,
The fueler is a Dubro Kwik-Fill Fuel valve. I have
one in my MUNK. The OS.90 in my MUNK is inverted and since I
finally got all the bugs out, I haven't had a problem starting
it. First thing I do is to choke it, give two clock-wise twists
of the prop, release the choke then hit it with the starter. It
fires right up.
The main problem was the gas tank. I inadvertently
mounted the tank right-side-up in an up-side-down fuse. Didn't
pick that up for awhile. I couldn't figure out why I was pissing
fuel out of the muffler when I tried to start it or once running
it wouldn't get by idle.
I'm not sure if the tank is a bit lower than the needle
valve, but I agree with Al, the positioning of the tank makes a
difference. OH...I'm also NOT using a muffler on the MUNK, just
a straight pipe and it runs great!
Ken
|
| 172.6 | | RAVEN1::TYLER | Try to earn what Lovers own | Fri May 04 1990 13:05 | 21 |
| I had problems with my engine flooding out all the time on my
Concept 30 coppter. A glow_plug that does not have the bar across the
end solved that. I got it from a friend and have no idea of its name.
But I know where he got it from and I'm going there to get more of
them!
---------------
/ __|__
=========[_____\>
/ __|___|__/
\ /
\*/
/|\
/ | \
| nn
| /oo\
-------- | / C
| @ @ |\\ \= /
| | \\ / \
-------- \\/@ \
/@ \ BEN
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| 172.7 | Guess whos tank was.......? | VERSA::TULANKO | | Fri May 04 1990 13:12 | 29 |
|
Thanks for the input, guys !!! I will definitely stay
away from the fuel pumps. Al, You brought up a good point that I
haddn't considered, about the pump working while priming the engine.
this would definitely compound the flooding problem. My biggest
concern was the engine flooding during low (normal) idle's. Unless
I kept the throttle set up for a higher idle, it would flood and
stall. Well, last night I checked the tank position and, low and
behold, guess who's tank was about 1/4" above the carb at centerline?
So it looks like I have a little adjustment to make. As far as in
flight characteristics go, the engine runs great, so it's "hands
off" the adjustments!
The quick fuel valve, by the way, has to be one of the
slicker ideas ever invented! I use them almost religously on all
my planes. As it goes now, I keep a spare valve plug around and
leave it plugged in the quick fuel port. This has been preventing
the flooding(fuel to ground) problem when the plane just sits there.
So thanks for the tips, Al and Ken !!! We will forget
ever hearing about pumps and rever to the age old priciple called
***** K.I.S.S.**** .
Thanks again,
Carl
|
| 172.8 | help | DNEAST::MALCOLM_BRUC | | Mon Sep 19 1994 16:41 | 9 |
| This topic has been dead for quite a while but I'll ask the question
anyway. After reading through this file it appears that a pump sys.
stinks.... although the plane I just purchased has the 6 oz. fuel tank
2" (on center) below the center of the engine. The engine must be
side-mounted for scale appearances. Can anyone add anything that would
help??
Bruce
|
| 172.9 | Pumps WORK | LEDS::WATT | | Tue Sep 20 1994 09:19 | 7 |
| ALL pattern engines are pumped. My tank is 15 inches back from the
engine on the CG. I couldn't fly without a pump. Engines designed to
be pumped work great. Don't try to pump a 40FP. If possible purchase
an engine designed with a pump like the OS46SFP, OS61, any YS.
CHarlie
|
| 172.10 | | DNEAST::MALCOLM_BRUC | | Tue Sep 20 1994 12:14 | 4 |
| does a Royal Pump match with a .45 Royal engine??
Bruce
|
| 172.11 | Go YS or OS | LEDS::WATT | | Tue Sep 20 1994 12:16 | 6 |
| I've never seen a Royal Pump except the ones that pump fuel into the
fuel tank. I doubt that the Royal 45 would respond well to a pump
though. It is not designed for it. Go with the YS45 or the OS46SFP.
Charlie
|
| 172.12 | Muffler Pump???? | FABSIX::C_MARCIANO | | Wed Aug 16 1995 18:55 | 19 |
| Another question about fuel pressure to the carb. I recently bought a
boat that was not complete. The boat has a EV60 engine. After I
thought it was ready to go I attempted to get it running and all it
will do is start then stall. I noticed that the fuel line going to the
carb. has no fuel in it after every try. I then went to the shop and
explaned the problem to them and they told me all I had to do was run a
line from my fuel tank (which is lower than the carb) to the muffler
pipe. He also gave me a small fitting to thread into the pipe. (peace
pipe is the brand of the exaust pipe). I fully understand his
instructions as far as drilling, tapping and inserting the nipple but
am unsure of where on the pipe I should put it or if it even matters.
I was also wondering it this will over pressurize the fuel tank and if
I should put something in line with this type of setup. I'm glad I did
not realize they made fuel pumps or I would probably really be in
trouble.
Any info would be greatly appreciated!!!
Thanks Carmine
|
| 172.13 | Need a little more info | SNAX::SMITH | I FEEL THE NEED | Thu Aug 17 1995 08:54 | 26 |
| I'm not familiar with the EV60 engine. Who makes it????? OS, Super
Tiger, etc.
Do you really have a "pipe" or muffler. A muffler attaches directly to
the exhaust port of the engine. Muffler's should already be tapped with
the pressure fitting. A "pipe" consists of two seperate pieces. The
"header" which will be a straight pipe that attaches to the exhause
port of the engine, then the "pipe" which attaches to the header with a
flexible coupling. Usually something that looks like VERY oversized
fuel tubing. The pipe will probably be about a foot or foot and a half
long. The side of the pipe that connects to the header will gradually
increase in size towards the center of the pipe. Then it will maintain
a constant diameter for the remainder of the pipe length. The exhaust
end of the pipe will be a little "pipe" maybe 2 inches long and about a
half inch in diameter.
Does the motor have a built in pump which would mean an ENTIRELY
different set of problems. Check the back of the crank case on the
motor. If it's just a plate that screws onto the back, you have no
pump. If there's some sort of mechanical devise there with fuel line
connections, then you have a built in pump.
So, can you clarify what you have with regards to pipe's and pumps/no
pumps.
Steve
|
| 172.14 | Missing Muffler?? | FABSIX::C_MARCIANO | | Mon Aug 28 1995 10:20 | 23 |
| The pipe mounts directly onto the motor via a small bracket that wraps
around the head. I have not noticed anything on the front of the
engine that has any fitting on it. As far as the engine goes it I'm
not sure what make it is but it looks identical to most of the 60's
I've seen in the showcase at the hobby shops except the carb. is
different. The pipe also has a stamp on it in big letters which says
peace pipe. The pipe is 2 pieces with 2 screws holding them together.
Does this mean I dont' even have a muffler?? I'll try to type a picture
which looks like the pipe.
Motor
*************
* *
* ****************************
* ******
* @ PEACE PIPE @ *
* Screw Screw * Output ?????????
* ******
****************************************
Thanks Carmine
|