Andair Valve Extension

Hi All,

I have searched the forums but still can't find the answer, does anyone have the ACS Part number for the Andair 6" valve extension that I have to get, the valve I have got from Vans but they dont have the extension.


Brgs Chad

Bootscooter said:

Hi All,

I have searched the forums but still can't find the answer, does anyone have the ACS Part number for the Andair 6" valve extension that I have to get, the valve I have got from Vans but they dont have the extension.


Brgs Chad

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If I remember correctly, it's a non-stocked item from ACS. Just give Andair a call or order off their web. I received mine in about a week after ordering direct from Andair. On this particular item it may be faster than dealing with ACS.

I just made the mount for my andair valve the other night. I made it out of two small pieces of angle and then a flat piece of aluminum and riveted close to the top of the tunnel. put nut plates on the valve itself so the tunnel cover can come off and the valve will stay in place. By moving the mount up you don't need an extension. At least it looks like it is going to work. Can get a picture tomorrow for you if your interested.

It does work but you end up with hassle trying to route the rear heat duct. Ask me how I know...........

stamper said:

I just made the mount for my andair valve the other night. I made it out of two small pieces of angle and then a flat piece of aluminum and riveted close to the top of the tunnel. put nut plates on the valve itself so the tunnel cover can come off and the valve will stay in place. By moving the mount up you don't need an extension. At least it looks like it is going to work. Can get a picture tomorrow for you if your interested.

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There is a reason why Van's move the fuel valve mounting point lower in the tunnel. It used to be higher in the early kits. Now you are forced to route the heater scat tube under the valve, which will heat your fuel lines creating a potential situation for vapor lock. Search on VAF for "hot tunnel", you'll find some interesting reading.

rleffler said:

There is a reason why Van's move the fuel valve mounting point lower in the tunnel. It used to be higher in the early kits. Now you are forced to route the heater scat tube under the valve, which will heat your fuel lines creating a potential situation for vapor lock. Search on VAF for "hot tunnel", you'll find some interesting reading.

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Exactly the situation I have found myself in. I plan to insulate both the fuel lines (fire sleeve) and the scat (heat mat) in that area. Having said that, I am not so sure that vapour lock is an issue with the rate the fuel moves past.

I have done a lot of thinking about this over the years, and more lately, about the hot tunnel problems. With the heater valves closed, the scat tubes can go anywhere and it shouldn't heat anything up because there is no hot air passing them. I think it is more likely that heat from a hot firewall will transmit through the aluminum (heat sink) tunnel walls that is connected with rivets. Even more of an issue with the hot air from the heat muffs dumping right on that area of the firewall. The firewall itself gets really hot. I think insulation on the inside of the tunnel keeps the tunnel cool more than the tunnel walls cool. Insulation on the outside should keep the pilot/passenger more comfortable.

Is my reasoning way off here? I haven't done testing, but this is my thought.

Bob,
In the current plans the scat runs over the top of the valve, not under it.

Jesse,
I agree with your observations. The hot tunnel was partially solved by the exhaust extension and downward deflection in the later produced kits. Also, using the stainless heat valves on the firewalls probably contributes to the cooler tunnel. I insulated the bottom of the tunnel with 2 layers of fiberfrax and one layer of 3/8" foam. Same with the firewall. My tunnel side walls are cool to the touch when the heat is off.

Bill.Peyton said:

Bob,
In the current plans the scat runs over the top of the valve, not under it.

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Correct, Notice that my response was to Stamper that solicited comments about him installing the fuel valve to the tunnel cover in a non-standard location. In his case, he has to run the scat tube between his fuel lines.

Sorry Bob, I mis-read!

Thanks for the correction on the fuel line and heat problem. I have a very early kit and the valve was mounted up high. Did not realize there was a change. If your heat is turned off would it be save to say there wouldn't be a issue. Could a guy turn off the heat a little before shut down to avoid vaper lock. I don't see where there would be a problem while flying due to how fast the fuel is moving through the lines and should not have enough time even with the heat on to effect the fuel. Given the tunnel is insulated. Would this be a correct assumption.

In my research on this I have never heard of a vapor lock issue with 100LL in the -10. BTW, I DO NOT have my fuel flow sensor in the tunnel. If I were you, I would build it to the current configuration with the valve as low as possible for two reasons. One, to get the heat above it: Two, to promote as much positive fuel pressure on the valve inlet as possible.

Three, so that if there's a leak, it won't leak on the scat tube.

Dave