Robert M

Well Known Member
I have some questions about the Van's fuel selector switch.

(Disclaimer: I'm gonna use it so for those of you that want to convert me, thanks, but not right now, I'll swap it out later should the need arise).

Anyway, on the plans, DWG 36, RV-9/A, the location of the switch with relation to the the rest of the forward fuselage is shown. The fuel line coming in from the left tank crosses under the selector switch and connects to the opposite side of the switch and the same is true for the right tank fuel line. The lever on top of the switch has a long arm on one side and a small point on the other. With the switch mounted per the plans, the long part of the lever points forward and to left. I believe the intent is to have this long arm indicate fuel coming from the left tank. The short part of the switch (with the little pointer on it) faces aft and right while the long part of the lever points forward and to left. It seems to me that a better way to install this selector switch would be to rotate it 180 degrees and let the short part of the lever, (the little pointer on the end), point to the proper tank that fuel is being pulled from. A simple "L" and "R" on each side of the mounting plate would suffice for keeping track of which tank your on.

Here are the questions.....

Does anyone know the logic as to why Van's designed the Fuel valve mount setup the way they did?
 
I think it mentions in the plans to file off the pointer, so the long handle is used as the indicator.
 
I think it mentions in the plans to file off the pointer, so the long handle is used as the indicator.

It does.

The handle it self can be seen and felt (in the dark) much more readily than the tiny pointer on the front of the handle. From a distance, depending on the viewing angle, the pointer is nearly impossible to see.


BTW it is usually referred to as a fuel selector valve (not switch).
 
There's nothing wrong with Van's valve. You can upgrade the handle with a new one if you choose. That valve is just a generic valve. Could be located in all sorts of configurations. Van's placed it where they did and as such its just works.
 
QB9A.. While building had enough builders say send back Vans selector valve and buy the ANDAIR fuel valve. Vans now sells that valve which is what I did to avoid the the pumbing nightmare yet to come when you put in the VANS fuel pump and filter. Ron
 
You actually have two questions mixed in there. The valve is oriented the way it is because it is easier to make the bends necessary if the lines cross under the valve than it would be to try to make them tight enough to reach the near side of the valve from where they enter the area between the sides of the structure supporting the valve.

Now that the valve body is dealt with, the handle orientation can be changed freely. I think I have heard (English for 'I have no real idea' :)) that some people have oriented the handle as you suggest. I thought about the orientation myself so I flipped the handle once I had the valve installed and sat in the cockpit and played with it. I found the forward-oriented handle easier to turn and much easier, as others have mentioned, to 'read'. Feel free to experiment on your own.
 
Original RV-6 is Different

I have the valve in my RV-6 installed per the older plans. OFF is with the pointer centered and facing forward with L & R being 90 deg to the left and right of center. You have to swing the lever a full 180 deg to switch tanks and you pass through OFF in the process - plus the "handle" of the lever faces aft and tends to rub on the cushions as you swing it. The newer setup allows you to switch tanks with less motion (+/-45 deg) and with the "handle/indicator" facing forward. It's a clever improvement.

Jim Sharkey
 
Robert,

Since you are going with this valve, why not put in bulkhead fittings in the supports on either side of the valve? This way you only have to make some short fuel lines to go from those fittings to the valve AND if you ever change the valve, you don't have to remake your entire fuel lines from the valve out to the wing tanks. One other minor thing, it makes crafting those fuel lines easier as you will have less bends.
 
PS. Check out this post:
What worked for me was to use a piece of clear nylon hose (the kind with reinforcing threads in it) with an inside diameter slightly larger than the outside diameter of the aluminum tubing. I put a few drops of tool oil in the nylon tubing and ran it from the hole in the brace next to the fuel selector, through the weldment and out the hole in the fuselage. I then put a slight curve in the aluminum tubing, burnished the end to remove any burrs, and pushed it through the hose from the selector side until it exited out the fuselage. The hose did a nice job of bending the tubing through the weldment. I then slide the hose off the tubing from outside the fuselage.

Here is the entire thread.