Pete1burn

I'm in the process of building a plane that has a cowl. How the heck are you supposed to fuel these things up? To take the cowl off, I first have to stick a long screwdriver through the side of it, and then take off the muffler with it.

Seems like a very tough way to go flying. I thought I remembered a couple of guys at the field who had their lines come outside the cowl into a quick connect or something and then back in. That right?

Any ideas/edumacation would be appreciated.

Thanks.

exeter_acres

My Feedback: (2)

I use Hanger 9 fuel dots

RCKen

My Feedback: (9)

There are several different ways of accomplishing fueling the plane with a cowl. They are running the fuel line out through the cowl and connected with a piece of brass tubing and ran back inside the cowl, an Dubro EZ fueler valve, and using fuel dots. Of the three I recommend either running the fuel line out of the cowl or using a fuel dot. The fueler valve (sorry I don't have a diagram for that) are a lot more trouble than they are worth, IMHO. What they are is a valve that is in the fuel line going from the tank to your carb and they have a fuel "probe" that you put on the line coming from your fuel can that is inserted in the valve to fuel the plane. Normally the fuel flows from the fuel tank through the valve to your carb, but when you insert the probe to fuel the plane it "cuts off" flow to the carb and lets your pump fuel into the tank. In theory they are a great little piece of engineering, but unfortunately in practice they can be a pain in the neck. One big problem with them is that when you remove the filling probe sometimes the valve will stick open allowing all the fuel in the tank to siphon out onto the ground. The other problem is the fuel probe needed to fuel the plane. If you ever loose it you won't be able to fuel your plane without buying an entire new valve to get another probe. I've had these fuel valves on several planes and have given up on them for good.

The easiest of the remaining options is to simply run the fuel line out of the cowl, cut the line, use a piece of brass tubing to hole the line back together, and then run it back into the cowl. When it's time to fuel you simply separate the line and fill the tank, and then put the line back together to fly. I've done this on many planes with cowls and it's a simple and easy solution, but I got tired of seeing the line outside of the cowl. It just ruined the lines of the plane IMHO.

The last option is my preferred method now, and that is to use a fuel dot. I use these on all of my planes with cowls now. They are sleek, look good on the plane, and are very trouble free. They are simply a round metal fitting that you mount in the plane and the fuel line runs out of that fitting, then there is a plug that plugs the fuel line, and finally the plug fits snugly into the fitting. To fuel or defuel the plane you simply pull out the plug, pull out the fuel line, plug you fill line into it, fill the tank, and replace the plug when done. While some will use a T-fitting to plug the fuel dot line into the fuel line from your tank to your carb, I tend to avoid this because it's possible to flood your carb this way. I prefer to set up a three line fuel system for use with a fuel dot. That simply means that you will add another fuel line coming out of your fuel tank, in addition to the normal fuel line and pressure line. The third fill line simply goes from the fuel dot to the tank. Make sure run a tube to the bottom of the tank from this line so that you can defuel the plane. Although it doesn't show in the picture I actually prefer to use another piece of tubing inside the tank and placing a clunk on the fill line to make sure I can pump out all the fuel from the tank.

I thing the fuel dots are great because they are so simple there really isn't anything to go wrong with them, and they look good on the plane.

Hope this helps

Ken

bruce88123

I agree with Ken on the fuel dots. I feel the "line thru the cowl and back in" method is poor because it gives you more failure points where air bubbles might also enter or lines tear. I've also used several types of fueling valves and they work for a while but all seem to eventually develop problems.

bruce88123

One of many sources:
http://www.horizonhobby.com/Search/D...uel+dot&CatId=

rclement

My Feedback: (1)

Yeah go with a fuel dot. They work great. The fueling valves tend to leak and may not even know it at first.

scratchonly

I've had very few problems with the sullivan plastic fueler; no O rings, simple principal.

NCIS

I use DuBro Kwik fills in all my planes and have never had a failure yet. Plus you don't have to mess with anything when removing the cowling. Just drill a hole in the side of the cowling and use a piece of 90 degree bent aluminum stock attached to the firewall and put the fill right next to the side of the cowl and you can just plug into it and fill her up. These kwik fills also stop fuel from going to the carburetor when plugged in for fueling. No hydro lock anymore. This is only my opinion.

Gibbs

Stickbuilder

I tried to use the Robart fueling valve on my last radial engine model, because the fueling valve could be used instead of one of the rocker arm blisters on the cowl. The thing leaked constantly, and allowed the engine to suck air. What a waste. Now I use a fuel dot, but I mount it inside a hatch so that It can't be seen. That's the price you pay for building Scale models. I'd reccoment the fuel dot on a trainer or a sport plane and mount it on the outside of the cowl as the guys have showed you. Have fun with it.

Bill, AMA 4720
WACO Brotherhood #1

R C Jack

If you are using a fuel dot, how do you know if you are overfilling the tank?

Thanks,

Jack

bruce88123

The same as on any other plane. Usually by when the fuel starts coming out the pressurization line to the muffler. I usually disconnect that line so the muffler doesn't fill and I have a small tank I connect to the line temporarily to catch the overflow so as not to waste it or spill it where not desired.

bigtim

My Feedback: (13)

I use the quick fueler and had no problems with leaking at all.
if you keep them clean they work great if they get gummed up they will leak.
for my fill vent lines I use a small "T" fitting off the pressure line from the muffler(in cowl muffler)fuel squirts out when the tank is full if you plug the muffler with your finger, when I am done fueling I plug it with a small socket head cap screw if you are running a 2st engine with standard muffler just disconnect the pressure line outside the cowl when fuel squirts out you are full.

rangerstl

Just as an aside, Dubro sells the fuel probe for their valves as a separate item if one should lose theirs. No need to buy the whole valve just to get the probe.

I have seen both fuel dots and valves in use. I chose a Dubro valve for my fun-fly Corsair probably because I just don't know any better. A problem I did not anticipate in my case was how to press the probe into the valve AND turn the fuel pump crank... Looks like I'll be getting an electric pump.

N

bigtim

My Feedback: (13)

the probe should hold its self in there when you are fueling mine does at least it seems there is a big knock on the dubro fueler about leaking can't say as I have ever had one leak yet and they seem to work well also they keep the mess down I fuel and de-fuel my tank using the fueler and run out any fuel in my engine at the end of the day.
seems like if your going to leave fuel in your lines then they might get gummed up and not work.
most of the time a couple of days after flying I will pop the cowl and check my lines,linkages, and muffler etc... so its ready for the next flying session the small amount of extra work is well worth not getting a deadstick on a warbird with a gummed up or clogged fuel line my shop is for working on my planes not the flying field.
like I had posted prior I use a small plastic barbed "T" fitting from the local ACE Hardware, I T off the muffler pressure line and plug the muffler and vent through the T'd off line out of my cowl the excess flows into a catch cup to be used later and I plug it for flying pretty simple and it works well, I just made a alum. bracket to hold the line after its been plugged for easy access and so its not flopping around banging the inside of my cowl.