Fuel T at front doorposts

[Dpearson]

I'm struggling with placement and orientation of the AN804-6D bulkhead tee where the fuel lines come together at the front doorposts (Station B-P). It seems that if I just drill the former and install the T as shown in the Bearhawk Book (image attached here), I will end up with a localized low spot (circled in red), where water could collect and freeze. The legacy build manual shows the tee at the same place.

IMG_3856.jpg
Am I overthinking this? How have others attacked this area?

[jaredyates]

Hi David, as years went on that tee got moved to the longeron, which you could still do but it would require welding. On our first plane I made aluminum wedge shims out of 1/4" thick bar stock, but I think most planes from that era just did it as drawn. It's less optimal but probably still good enough.

Wedges: http://bearhawkblue.com/wp-content/u...4/P1000402.jpg

Longeron mounting

http://bearhawksafety.com/4-place/noticeapr11.html

[Dpearson]

Hi jaredyates I like the wedge idea! The "no welding" approach aligns well with my feeble welding skills. I've ordered up some bar stock from Amazon Aviation and will give it a try.
Thanks for the tip.

[Dpearson]

Success! The wedge idea from jaredyates worked great. I started with 1" square 6061 bar stock, drilled one end to 9/16, rough cut on the band saw, then finished them up on the disc sander. Easy-peasy.

[Battson]

I'm struggling with placement and orientation of the AN804-6D bulkhead tee where the fuel lines come together at the front doorposts (Station B-P). It seems that if I just drill the former and install the T as shown in the Bearhawk Book (image attached here), I will end up with a localized low spot (circled in red), where water could collect and freeze. The legacy build manual shows the tee at the same place.

IMG_3856.jpg
Am I overthinking this? How have others attacked this area?

I think the manual grossly overstates the risk of water freezing and low points in general. In a decade I've only had water in the fuel tank once, after refueling in the rain, and it was a tiny amount. I am sure there's some risk, but it is very minor.

It is very challenging to make a fuel system without a low point (undrained), unless you install an excessive number of drain valves (don't do it).