Completely cowled in engine. Cannot get to fuel lines. Have 3 line system at tank. When refueling how do I determine when the tank is full short of filling up the muffler till it runs out???

No, I cannot disconnect the pressure line from the muffler.

No, I cannot disconnect the line to the carb.

A "T" fitting in the pressure line will not work as fuel will come out of both sides.

I'm using an electric pump so I can't count turns of a nand pump.

There's gotta be a way. I'm stumped.

Any help will be appreciated.

Phil

The fuel will simply come out of the muffler.

Make an inspection port so you can see the tank.

Or remove and toss the cowl.

I have one cowled model I use a pair of hemostats to pull and replace the fuel hoses (I use red for supply/raw and blue for the muffler line so I don't accidently cross them).

Just add a check valve between the "T" fitting and the muffler.

Muffler pressure can go IN, but fuel can't go OUT

actually if you use a small T fitting it will work, how do I know, its how I fuel my H-9 P-40.
fit the small "T" bellow the pressure line fitting in the muffler, I use the cross part of the "T" for the over flow so its a strait line and the side off the T to the pressure fitting, then run the line out of the cowl.
I made a custom line holder out of alum. "L" stock,just a fuel line size hole to hold the line when plugged that I screwed into the fuse, I plug the line with a small socket head cap screw after I am done fueling.
while filling plug the muffler with your finger or a stopper and run the over flow to a catch cup to get the exess fuel that will run out, there will be about a 1/4oz of fuel that runs out as over flow.

I have a similar situation with a Cap 232 and my solution was to fill through a third line. I put a T connection in the vent line which is normally plugged. I also made the vent line to the muffler long enough that a small loop emerges at the bottom of the cowl. I use a clothespin with a rubber band around the end to pinch that portion of the line when fueling, and the other end of the vent goes back to the fuel jug. The clothespin prevents fuel from going through the vent into the muffler. Just remember to remove the clothespin.

Note that I originally tried to use a Hemostat, but the hemostat had a tendency to cut the fuel line. The clothespin works better and cheaper.

Brad

Minnflier's way is the neatest and cleanest. or I've used an extra long piece of fuel tubing for the vent line so that it drapes a little below an opening in botton of cowl. Cut the line and insert a piece of brass tubing that you can diconnect while fueling

I would just use a fuel line plug and plug the line you don't need and then put a DuBro Kwik fill on a 90 degree bent piece of sturdy aluminum stock on the firewall just in far enough so the cowling clears it. Drill the aluminum stock with a 3/8" bit and the quick fill will slide through and then add the nut for a secure fit. Then drill a hole in the cowling where the fuel fill is and you can fuel the plane without taking off the cowling. A fuel dot requires removing the fuel line every time you need to remove the cowling. A nice feature about the Kwik Fill is it shuts the fuel off to the carburetor when fueling to avoid flooding. If the fuel come out the muffler it is full. I usually make my cut out on the cowling for the muffler large enough so I can get to the fuel line and remove it when fueling. That way you don't fill up the muffler. When the fuel comes out the line it's full. This is just my method and it works great.

Gibbs

Warning: All of the so called "quick-fill" devices utilize a spring and an "O" ring seal. They fail occasionally. Guaranteed, all of them will fail at some time...sooner or later..it will fail, believe me...I've been there, done that, etc etc.
The failure mode is an incomplete seal...which allows air into the fuel stream...the motor runs erratically at first and then runs lean...and then it runs no more.
Save yourself a lot of grief and expense. Use the KIS principle. "keep it simple".
A fuel dot is as cheap and simple as you can get..and as reliable as you would ever expect anything to be.
Go with MInnFlyers one way valve if you need to save the mufflers worth of fuel...yes, it can add up over time.
As for the infernal fueling devices...keep away from them, and advise your friends to do the same.
If there's someone you really dont like..buy them one or two fuelers for Christmas.
Happy Holidays.

retracted

Squires original criteria was to avoid filling the muffler with fuel, only to have it go to waste...hence MinnFlyers one way fuel check valve, and overflow dot in the muffler pressure line. Filling would still have to be via a fuel dot in the third line. Filling from the top/muffler pressure line would cause fuel to be immediately gushing out of that third line.
One other item being overlooked is....if it is a gasser, (walbro carb) it will not allow fuel to flow to or through the carb under the pressure from filling the tank...however, a glow fuel carb has no such restrictions, and of course while filling the tank, you would be filling the crankcase of the motor as well. Not a good idea!
Thats where a little hemostat would come in handy to pinch of the carb line while refueling....assuming you can get to it.

I do not believe this will work. Once the other fuel line out of the T fitting is plugged after fueling, when the engine runs the muffler will pressurize the tank. But, go to full throttle and pressure will keep building up in the tank. Now go to idle and all that pressure in the tank that cannot escape through the vent tube because of the check valve will flood the engine right away. There is no way you will be able to get the engine to run correctly with a check valve.

To avoid filling the muffler, put a break in the muffler line that can be accessed from outside the cowl and disconnect it, fill the tank, then connect the tube back again when done filling tank.

Tom

KISS...is the best way,three way fuel tank setup with either a check valve or loop in the muffler fitting as was said here with an in line connector that you hang out the bottom of the cowling and disconnect when fueling.i like the fuel dots and use the loop in the muffler line myself.i have an old fuel tank i put the unplugged fuel tank side line into when fueling to save any spilled fuel

I have used Kwik fills for years and if you keep them clean they won't fail. Your just being cheap and not wanting to spend the extra money what $12.99. If this is going to break you maybe you should get into knitting. I can't believe that DuBro sell thousands of these a year and they are failing. They would quit making them in my opinion if that were the case. Use your old time fuel dots and leave technology to us that want improvement. I didn't cut down your fuel dot method until now because you came back saying my suggestion is crap. Well so be it.[:@]

Gibbs

I've seen the check valve used many times w/o the "T" and it works just fine. It helps to maintain constant pressure at all engine speeds. It's actually an old trick used for years.

NCIS - I believe you meant to insult Capt Jim but you replied to Horace. If you would please be so kind in the future to address your insults so that they may know who offended you the most.

allot of my way is better stuff here, pretty confusing if I did not have a set up already in place that works fine for me.
I wonder if anyone has used a check valve and how do you explain how the air escapes to the beginner trying to set his plane up wasn't that the question? how about some photos of your supposed set ups and what parts are you people using instead of insulting each others fueling methods.
I use a EZfueler and have had no problems and also fuel dots they both work fine.
one thing I do know if you don't vent your tank when filling, you will flood your engine if your going to pinch the vent line off to prevent the muffler from filling with fuel.
if you are using a check valve then show the complete system and the actual parts being used, so there is a complete vision of what parts are needed and where to get them.
I knew what was being said, but is a beginner trying to figure out something he has not done before?

This is part of what I started to point out in post #10 prior to retracting the post. Minn IMO should have shown the entire system more clearly. I eventually realized that all he intended to show was the CHANGES from a standard 3-line system. The partial drawing left room for mis-interpretation, which I did at first.

i have set up many planes with the filling valves and had problems with some of them i have used,i have several in my flight box still that i removed.i have seen some people use them and never had one days problems.they are a neat way of filling a model,i was at the mindset that since something cost'ed more it would be an improvement but that is not always the case.whatever works for you is what you will use.i would never intend to make insults and haven't so far taken anything that was said on these posts as an insult,RC Universe is like one big library,when we all put our minds to it we can figure out any problem or suggest and help one another.i was a mechanic all my life and there was always someone that had a better idea or easier method of doing something and i am always open to suggestions.it all boils down to preference and personal choice.if someone makes a suggestion here and a new pilot has questions then they should pm or post to have a diagram of what was said.these moderators here do a fine job of helping and guiding people to others than have and can help.

Well i have tried it and it definitely doesn't work for me the engine always floods out at low end. A check valve can only work when there is a regulator like a cline in the carb line. Maybe this is what you saw, a check valve and regulator to go with it.

I used a T on my only cowled plane and the fuel come out of the extra line at the same time as it comes out of the muffler (knowing this I really don't need the T)
The amount of fuel in your muffler, if you stop fueling right away when it starts coming out, is minimal (less than a teaspoon) and will blow out when you start the engine.
IMO all the extras are a waste of time and just more things to fail in the future.

bruce88123,

I didn't mean for you to think it was directed at you. I thought he would know it was directed at him. I don't cut anyones methods down and didn't appreciate him cutting down my method. I am sorry it seemed to be directed at you.

Gibbs

Hi Bruce This is Phil Botto alias Squire

Thanks for the response. I didn't get much help in Engines or ARFs so I posted here. It seems after reading these that I really have two practical choices to try - 1) do nothing and let the excess run out of the muffler which will probably work as the engine is at about a 225 degree angle putting the muffler right below and on the centerline, or 2) put a LONG pressure line in with a piece of brass tubing that I can get to so I can break the line while fueling. These options seem simple and I am big on KISS! The check valve and "T" fitting seems to be a lot of work and something else to fail. I bought a Dubro fueler but don't think I'll use it quite yet.

This plan that I'm assembling a Phoenix Decathlon and it is really shaping up nice.

Thanks for you help. Tell everyone down at the field hello from me.

Phil

Hi Phil, never would have guessed that was you. Any way, the check valve works OK. I've actually got one on a plane I got from Harold and it works fine. It doesn't have a "T" it the line though. You would end up with 2 DOT's, one filler and one vent. Not too bad really if you want to consider it. Get the parts and let me know some day when you can get by SAM and I'd be glad to show you how it hooks up personally. If you decide you don't like it, it would be easy to remove.
Good to hear from you.

One example I know of is on a plane of mine and I KNOW it has no regulator and idles and flies just fine. I can not explain your dilema.