Howto install Andair FS20X7T fuel selector with the high pressure fuel pump?

Is anybody using the Andair FS20X7T fuel selector valve (that's the version Van's sells) with fuel injected engine (i.e. with the Airflow Performance high pressure fuel pump that Van's sells)? I can't seem to make the geometry work.

The fuel line to the fuel selector from the right wing tank interferes with the aft fitting on the fuel pump's manifold. I think there's just no way to make the bend in the tubing tight enough as it comes off the fuel selector to avoid this interference. Am I wrong?

I've also looked at rotating the fuel selector's fitting 90 degrees so it's facing aft/outboard instead of down. But then the fuel line will interfere with the side cover panel.

What am I missing? It seems like this installation might only work with the Andair banjo fittings. But I thought this version of the fuel selector and fittings were especially designed for the RV-7 installation. Maybe just not with the high pressure fuel pump?

Anybody who's made this work, I'd love to hear how you did it. Or better yet see some photos. Thanks!

I have the same components so I'm interested in what you come up with for a solution, although I'm quite a ways behind you at the moment. I remember coming across this little item on Van's site:

http://www.vansaircraft.com/cgi-bin/catalog.cgi?browse=hardware&product=F-Swivel-Tee

If you use the Airflow Performance fuel pump AND an Andair fuel selector, this AN6 size fitting makes plumbing the return line from the pump to the valve easy.

Click to expand...

Sounds like exactly what you need...?

good luck,
mcb

A picture is worth a thousand words...

... so here's a photo of the interference.



P.S. Matt- Yes, you'll need that "F-Swivel-Tee" fitting for the output port from the selector valve. You can see it in the photo. That's kind of a drag. It seems here too if the valve had a female NPT fitting instead of a flared tube fitting, you could use a standard AN Tee fitting instead of this funky, non-standard, single-source, $20 "F-Swivel-Tee". Oh well.

Two options

Roee,

The way I see it you have two options.

1st. After exiting the bottom of the valve, have the line run aft to the spar and then do a 90 degree turn to the right side of the fuselage. (That's how I ran my line. See this picture)

or

2nd. Put a 90 degree elbow fitting on the bottom of the valve and run the fuel line straight to the elbow.

Also, from what I see the way you ran your line, you will have a problem with the cover that is supposed to go around the valve because you are coming in from the side and not straight forward from the spar as I have done. I do not know if this is required due to the fuel pump you are using for your FI set up.
Good luck.

Bill, looks like your valve has the female NPT ports, which would make life much easier. Whoever you bought your valve through, looks like you chose a better configuration than the one Van's offers. You can put in standard AN fittings and orient them in any direction you need, which would solve my problem by angling them aft slightly. With my valve though (the configuration that Van's sells), the valve's ports are built-in 90 degree flared tube fittings (see photo), so I can't put an NPT elbow on top of that. That's the problem...

BTW, disregard the direction that the tube exits in the photo. I just put that piece of tubing in for the photo, to show the interference against the fuel pump. The interference is there even if the tube bends straight aft, which I agree is the orientation it should be.

Does this help? I have the FS20X7 valve and it works great. Sorry I dont have time to write commentary but perhaps a picture is worth 1000 words.

Banjo fittings

I have the FS20x7 with the AFP boost pump. I used banjo fittings and made my own stainless braided fuel hose to run between the selector and the wing tanks. This allows for a LOT of flexibility and a neat result. It looks a bit cramped in the pix but I actually have quite good spacing between all components.

It's not the cheapest option but most of the fuel lines I see on other projects look like mangled spaghetti bolognaise.

At any rate I would highly recommend the banjo fittings (with or without the flex hose).

Just one option. Click on the pix for a larger image.

Regards Bob Barrow

roee said:

P.S. Matt- Yes, you'll need that "F-Swivel-Tee" fitting for the output port from the selector valve. You can see it in the photo. That's kind of a drag. It seems here too if the valve had a female NPT fitting instead of a flared tube fitting, you could use a standard AN Tee fitting instead of this funky, non-standard, single-source, $20 "F-Swivel-Tee". Oh well.

Click to expand...

Oh I get it... sorry, for some reason I didn't properly read which area you were talking about.

For what it's worth, here's how I ran my lines: http://www.rv7blog.com/index.php/2006/07/15/fuel-plumbing/ I don't have the pump yet so hopefully this will work out. Now I'm glad I sprung for the version of the valve with banjo fittings, in case I run into this same trouble down the road.

btw, who wants to place a bet on whether or not Van's "F-Swivel-Tee" is properly stamped with AN markings?

mcb

I actually bought a swivel tee from Earl's Performance products. My money is that this is the one Van's is supplying. I did a lot of research to ensure it had the correct 37 deg flare on there. However in my final installation I got away with using a standard fitting.

I also tried obtaining some banjo fittings to make the whole installation easier but I could not obtain them either in the US or UK. Andair was soooo backlogged that they couldnt get any to me. So I made it all work with standard fittings.

andair valve plumbing

I had the same problem and this is what I came up with. With a little experimentation I was able to get the lines to clear the cover. PITA, glad that's over. I also had the gear weldments to deal with.

I agree with you. It doesn't fit just quite right. I replaced their straight out fitting with a 90 degree. At least I think it was a 90 may have been a 45 just can't quite remember. I'll check it tomorrow.

This is the fuel selector specifically designed by Andair to overcome the problem that existed before !

If you route the lines like Scott did and put another junction outside the F738, you can easily route the tubing where they should go - no banjo's, no fuss, no interference. Also, the tube can be taken out if you want at a later date during maintenance.

The original tube routes shown by Van's are virtually impossible to do unless you incorporate some of them during a construction sequence. QB builders find lots of areas where the later fitting of parts or skins is very difficult due to existing structure being completed by the QB ers for you - reinforcing around the tip up is a good example - try setting some of those rivets

What I've learned...

Thanks to everyone who responded. So here's what I've learned:

Sounds like Banjo fittings are a good answer that's worked for quite a few builders. I've gotten in touch with Owen at Andair, who (contrary to some accounts on this message board) has been very responsive. So I'm hopeful that I'll be able to get some Banjo fittings pretty quickly.

I've also come up with a couple of other possible solutions. I'll describe them here just for fun. But note that they're only ideas, I haven't tried them.

Alternate idea 1: Use Andair's female NPT fittings. Then connect an AN913 male-to-female NPT 90 degree elbow, pointing more-or-less down. Then connect to that an AN822 (90 deg) or AN823 (45 deg) elbow NPT to flared tube, pointed more-or-less aft. Gives similar flexibility to banjo fittings, but using just standard AN hardware. Probably a little more bulky, but actually provides more degrees of freedom in which direction the tube exits.

Alternate idea 2: Using Andair's 90 degree elbow flared tube fittings (the ones I currently have). Connect to that a non-standard swivel adapter that attaches to the flared tube fitting. Just like the "swivel tee" that Van's sells for the output port, I found that you can get a variety of similar adapters like 90 degree or 45 degree elbows with swivel flared tube fittings. Now mind you none of this is standard aircraft hardware (including the swivel tee that Van's sells), so use at your own risk. But it's supposed to be AN compatible, 37 degree flares. I discovered that this stuff is sold primarily for race cars, which apparently use a lot of AN hardware. A couple of companies that make this stuff include Earl's Performance Plumbing (a division of Holley carburators) and XRP. Googling "earls fitting adapter" for example gets a ton of hits for online stores for auto racing supplies that sell these fittings (some at considerably cheaper prices than Van's).

...
On a related topic, the choice of a flared tube fitting on the lower (output) port of the Andair valve is also not ideal for a fuel-injected RV-7/9. It requires that funky "swivel tee" adapter that Van's now sells. (Again, this adapter is not standard aircraft hardware, so use at your own risk.) The adapter serves the purpose, but it's kind of a kludge. If however instead of a male tube fitting the valve had a female NPT fitting, one could just use a standard AN826-6D "Tee". So it seems to me the preferred Andair fuel selector for a fuel-injected RV-7/9 would actually be a "FS20f7B".

Next task I'm looking forward to will be getting the fuel lines routed through the gear mounts, geometry a la M. C. Escher...