School Me On Fuel Line Setup

[AzMandella]

So I have been looking a lot and see that most people are using a tank , hopper tank and remote needle . Also see they are running a line from the pipe to the tank . I'm not quite sure what the remote needle is being used for . And the line from the header to the tank . I'm guessing is to pressurize the fuel tank . Not sure why but you have to be heating the fuel up reducing HP . Keeping the air fuel mixture cool always builds HP . If someone doesn't mind I would like to see a fuel system routing diagram .

 

[Hydro Junkie]

The pictures you have seen are pretty much what is the norm. Let me give you a run down since I'm at work and don't have access to pictures at the moment. I'll be starting at the tuned pipe pressure fitting:

1. Pressure Line-This is used to push pressurized exhaust into the main fuel tank(s) vent tube. This is used to maintain a constant fuel flow to the engine. If this line is omitted, it can cause an uneven fuel flow and an engine that won't run well. It also will affect the needle setting that regulates fuel into the carb
2. Main Tank- No explanation really needed here. It's where a majority of the fuel is contained. Just an FYI, the location can affect the balance of the boat based on how much fuel(AKA weight) is in the tank
3. Transfer Line- This is probably not the name everyone uses but it is descriptive for me. It is connected to the pick up tube in the main tank and will route fuel to one of three places; the hopper tank vent tube(if used), the remote needle valve(if used) or the carb fuel barb
4. Hopper Tank- This tank is used to add a small amount(usually between 1 and 2 ounces) of fuel to the total amount carried. The reason it's included is to prevent the engine from stalling due to lack of fuel when the main tank gets down. When the main gets down(under half full is when we can see this start), the fuel may start to slosh around the tank and can leave the pick up tube out of the fuel for a short period of time. This will create air bubbles in the fuel line. When the air bubbles get to the carb, the engine dies due to lack of fuel. The hopper tank is used to filter out these air bubbles so that the fuel flow to the carb is not interrupted
5. Supply Line- This is the fuel line from the hopper(or main if no hopper is used)tank to the carb. It can be routed to a remote needle valve before the carb as well
6. Remote Needle Valve- This is used to allow the fuel flow setting to be changed by the operator while the boat is running by one of the radio channels. It can be used with carbs both with and without needle valves, depending on the operator's preference. I personally don't use one but many swear by them
7. Carb Fuel Barb-This is the last fuel line fitting in the fuel system.

I'll see about taking some pictures of the fuel system of one of my boats either tonight or tomorrow unless someone else can post something before then

 

[FloridaScaleBoater]

nice description, good job.

 

[Mike Cathey]

Put the needle valve as close as you can to the carb inlet so any changes happen almost immediately. Buy more tubing than you think you need because some will get messed up bending it.

 

[AzMandella]

Thank you . I was pretty sure the header line was to pressurize the tank for even fuel pressure . Was not sure about the hopper tank but makes complete sense .

 

[Hydro Junkie]

Glad I was able to clear up some of the "grey" areas. I would agree with Mike on the tubing. It's easy to crush the tubes so you need to allow for wide radius bends. What I use to prevent the tube from crushing is this:
5-piece Spring Type Tube Bender Set (micromark.com)
I know there are other tube bending tools out there, the spring set just works for me.
Something else you need to consider is how you route your soft fuel lines. It's best to avoid sharp bends as it will kink the line, shutting off fuel flow in the same way as with brass tubes. It's also preferred to keep the lines as short as possible.

 

[Walt Barney]

Glad I was able to clear up some of the "grey" areas. I would agree with Mike on the tubing. It's easy to crush the tubes so you need to allow for wide radius bends. What I use to prevent the tube from crushing is this:
5-piece Spring Type Tube Bender Set (micromark.com)
I know there are other tube bending tools out there, the spring set just works for me.
Something else you need to consider is how you route your soft fuel lines. It's best to avoid sharp bends as it will kink the line, shutting off fuel flow in the same way as with brass tubes. It's also preferred to keep the lines as short as possible.

One other thing is that most metal fuel tanks will have a hopper tank inside the main tank so a external hopper usually is not needed unless you need the extra fuel.
Walt Barney

 

[Hydro Junkie]

One other thing is that most metal fuel tanks will have a hopper tank inside the main tank so a external hopper usually is not needed unless you need the extra fuel.
Walt Barney

This is true, but I didn't bring it up since there are only a few sources for metal tanks. Correct me if I'm wrong but most of them are direct order and only make tanks to fit specific boats.
With all that said, do you make a tank to fit the Dumas Eagle sport 40?

 

[Julio Almazan]

Hi:
Hydro Junkie,
I really liked your extensive and precise description of each of the elements involved in the transport of fuel ...
Would you recommend any special fuel cooler gadget? ... and we must always remember the issue of using fuel filters

One other thing is that most metal fuel tanks will have a hopper tank inside the main tank so a external hopper usually is not needed unless you need the extra fuel.
Walt Barney

Could you put some pictures of those tanks?
Thanks a lot.-

 

[Hydro Junkie]

Hi:
Hydro Junkie,
I really liked your extensive and precise description of each of the elements involved in the transport of fuel ...
Would you recommend any special fuel cooler gadget? ... and we must always remember the issue of using fuel filters

I don't know of anyone that makes a fuel cooler so no, I can't recommend one. Come to think about it, I've never seen anyone run any sort of cooler on their boats either. With the relatively short run times of R/C boats, heating of the fuel hasn't been an issue since, except for the really large gas boats, we're only looking at 5 to 10 minutes. You also have to remember that a vast majority of our boats are water cooled and all have to have air for combustion so heat's not an issue when it comes to fuel.
As far as fuel filters, using one somewhere in the system is a give. This is especially true when running fuel with castor oil. Since castor oil is a plant based product, it can have fibers in it from the plant it's made from and those fibers can plug the needle valve

 

[Julio Almazan]

Hi:
Isaid something like this:

https://www.aliexpress.com/item/327...earchweb0_0,searchweb201602_,searchweb201603_

 

[Walt Barney]

This is true, but I didn't bring it up since there are only a few sources for metal tanks. Correct me if I'm wrong but most of them are direct order and only make tanks to fit specific boats.
With all that said, do you make a tank to fit the Dumas Eagle sport 40?

I do not have the sizes for your tank this is what I will need
Length
Front width
Rear width
Front height
Rear Height
anything special you need?? just a rough drawing would help.
thanks
Walt Barney

 

[Walt Barney]

Hi:
Hydro Junkie,
I really liked your extensive and precise description of each of the elements involved in the transport of fuel ...
Would you recommend any special fuel cooler gadget? ... and we must always remember the issue of using fuel filters

Could you put some pictures of those tanks?
Thanks a lot.-

I will get a couple of pictures up in a couple of days as I just got back from Huntsville.
Thanks
Walt Barney

 

[Hydro Junkie]

I'll remember that when I get to the point I'm ready for a tank. I'm waiting on new FG cowls at the moment so it may not be until after the holidays

 

[Walt Barney]

I will get a couple of pictures up in a couple of days as I just got back from Huntsville.
Thanks
Walt Barney

 

[Walt Barney]

Cannot get the pictures to this site I can get them to you thru my email [email protected]
let me know
Walt Barney
P S This is not my computer it took a dump so I borrowed this one.