jbrundt

My Feedback: (2)

I want to install some fuel dots (I'm thru with E-Z fuel valves) and need to see some plumbing diagrams on how to hook them up. I'm curious how you by-pass the fuel line to the carb when fueling/defueling.

Thanks,

Jeff

piper_chuck

My Feedback: (12)

When you use a fuel dot, the tank should have 3 lines, one for fueling/defueling, one for pressure, and one to the carb.

Richard L.

My Feedback: (24)

Yes, use a three-line system on any engine other than a YS. With a YS, use two lines with two tee's and two fuel dots.

JoeAirPort

My Feedback: (41)

I use the two line system with my Cline regulator (very similar to the YS).

jbrundt

My Feedback: (2)

Thanks guys.

I guess when you fuel it's not a big worry for fuel to travel up the carb feed line, right? Any overflow should go out the vent line.

Jeff

JoeAirPort

My Feedback: (41)

You are correct. If you want you can put something under the muffler to catch it. Or disconnect the vent from the muffler and put an overflow bottle to catch it. Either way it will go through the vent and will not flood your engine.

RC-Captain

My experience with dots and third lines is zilch, but about two weeks ago I got so fed up with removing the line going to the needle valve , I tried using the line going to the carb and it worked like a charm. A little more time but much easier to work with . GL

RCF esq.

Turk1

Why not an easy fueler instead of dots?

Richard L.

My Feedback: (24)

Because fuel dots are fool proof and leak free. They are just plugs for the fuel lines, so there is no way they can fail. Plus, they are simple.

osprey1

My Feedback: (1)

I too am fed up with easy fuelers but my planes are set up with two lines to the tank.
My tanks access to add the third line isn't good.
With a new build I wil add the third line.
My question is: Can I just tee a fuel dot into the carb. line?
I know fuel will travel in both directions, towards the carb. and towards the tank.
Will the fuel tend to fill the tank rather than go thru the carb.?
Once in the carb. will it continue into the cylinder and then create fuel lock in the engine?
Thanks.
Looking for an easy rework.

Uh-Oh!

osprey 1, look at this... http://www.slimlineproducts.com/onli...cel_fueler.htm The o-rings prevent the fuel from going to the carb. Simple and effective but, a little deep distance wise.

Dave

da Rock

It won't if you turn your prop so that the intake hole in the crank is closed. But the amount of fuel that's going to be pressured through the spray bar into that crank hole depends on how hard you pump the fuel into the airplane. Sometimes if you pump easy there won't be any fuel out the spray bar. Also, the mounting direction of the engine may tend to slowly turn the crank back open, or it might hold it closed for you. And obviously if your carb opening is pointing toward the ground any fuel flowing out the spray bar is going to drip out of the carb.

moodier

My Feedback: (1)

Hi;I just use a T in the carb line and then reach in with one of those medical?clamps and clamp the line usually can reach it somewhere thru the cowl when I have no third line!I am usually doing this on a 4 stroke where even with the vent line on the fuel runs out of most installations. Now I suppose on a 2 stroke upright and leaving the vent line on you could really fill the muffler!

da Rock

Putting the third line into a tank is dead easy. All the hard work is in putting a vent into the tank so that it opens at the very top of the tank, and you gotta do that no matter what kind of tank you're putting together. So adding the third line is just sticking a short tube into the third hole. Of course, you usually have to open that hole but that's dead easy too.

I used to run uniflow in everything I flew, even fuel RC. But it pretty much requires you to use either the pickup line or the pressure line as your fuel input line and you have to open up your vent line while fueling as well. And you then have to plug the vent line and reattach your fueling line (unless you've plumbed that line with a T and fuel dot). I'm not flying competition any more and have discovered that I really don't need uniflow on anything I fly eventhough I FLY them suckers HARD. So I make tanks that're very simple to use at the field and lot's easier to stick together than uniflows are.

Three tubes: One vent that curves to the highest point in the tank. One line that just sticks through the stopper. One line that sticks through the stopper and gets the clunk line.

Plug the line from the carb to the clunk line tube.
Run a fill line to the short tube that just sticks through the stopper. This line is plugged except when it's used to fuel the tank. I use a 1/4" 6-32 bolt with a large head that's easy to grasp. My lines barely stick through the fuselage side or cowling bottom or on the Sukhoi, just hang there in that big old open cavern.
The muffler pressure line runs to the tube that runs to the very top of the inside of the tank. When I crank my fuel pump, the tank fills until it's full and then starts to spit overflow out the muffler. I give the crank half a turn backwards to stop any siphoning that might be going to the carb, pull the fueler and stopper the line into the airplane.

I also count how many cranks it takes to fill the tank. It's a habit I picked up flying competition CL aerobatics. It does a number of wonderful things. It proabably is going to be a problem for you guys flying the big birds. It tells me when an empty tank is about full and on later flights how much fuel I had left from the previous flight. It also helps minimize the amount of fuel spit into the muffler.

When I first started flying this simple setup, I really wanted to see just how bad it was going to be compared to my Uniflows. I flew the test airplane with it's old, perfect feeding uniflow and immediately swapped in the new tank. Set the needle and flew. Outside loops, long inverted flight, squares inside and outside, snaps right side up and upside down, and flew until it went dry in the air. I couldn't see or hear enough difference that it mattered.

Only having to uncork one line, and that being the one the fuel probe is going into, is nice and easy. And no extra plumbing is even easier. I've never bothered to buy a fuel dot and chuckle ever time I'm in the LHS looking at all that plumbing stuff they want all that money for.

da Rock

BTW, I have one upright engine installation where the overflow has a chance to pool inside the muffler when the tank is full.

Long ago an auto mechanic warned me that the new car I was buying had a bad habit of rusting out the bottom of it's muffler. He said I ought to drill a couple of small holes at the very lowest points on that muffler. I did. There was no extra sound and the muffler lasted as long as the car (90 some thousand miles).

I drilled a small hole in the Max's muffler so I'd see the overflow into the muffler as soon as possible. It worked too.

osprey1

My Feedback: (1)

Thanks for all the advice. I will adhere.
I have no problem putting in the third line on a new build.
Its just getting access to my fuel tanks at this time.
Alos, I like to pump out my tanks at the end of the day so I think I will
have to put a clunk on the third fill line.

piper_chuck

My Feedback: (12)

Here's a diagram showing my 3 line tank setup, and a picture of the most recent one I assembled. The left pic of the stopper shows how it will be aligned in the tank. The one on the right shows how it is aligned when I put it in the tank. Once it's in I just rotate the tub so it's in the bottom front corner. To completely empty the tank I just prop up the tail a bit and I can get it emptier than with any clunk setup.

desmobob

The third line is the way to go.

I've been doing something different other than using a second clunk. I angle the third brass fuel tube toward a back corner of the tank and run a piece of silicone fuel tubing from it so it's a little bit short of a back corner. I cut the tubing at an angle so the opening is on the bottom of the tubing, parallel with the tank bottom. The fuel pick-up clunk can easily swing back and forth behind it, and you can still empty your tank almost completely dry at the end of the day by tilting the model just a bit toward the side you have the third line angled toward.

No need to buy extra clunks, and no worries about the two clunk lines getting snarled up somehow during aggressive aerobatics or exciting landings like mine....

Good flying,
desmobob

Good flying,
desmobob

RC-Captain

Although old news , I am using on a GASSER engine a tee with a fuel dot/plug. Who ever mentioned the sergical clamp was dead on. But I have a better ordinary tool to use . A pair of needle nose pliers with a rubbeband around the hand to make it retract to the closed position.



CAP