Fuel sight gauge confusion

[Pbruce]

I am trying to replicate the sight gages as prescribed in the Bearhawk builder tips. I bought the schedule 40 1/4” ID tube called for, but it’s way to big to fit on the barbed end of the elbow fitting. I could move up to a bigger elbow which might fit tightly into the schedule 40 plastic tube, but then the the other end of the fitting would be too large in diameter to mate with the the 1/4” OD aluminum tube coming off the union which fits into the bung in the fuel tank. (Sight gauge bungs are for 1/4 tube whereas fuel supply tube bungs are for 3/8”. See picture). What is the resolution?

[jaredyates]

I believe the missing link is that you'll need to cut 1/8 NPT threads into the pvc, and use an elbow fitting that has 1/8 NPT on one end and a flare on the other.

[Pbruce]

Ok thank you. I will look into that fitting. Much appreciated

[rodsmith]

AN822-4D is what you need.

[Pbruce]

Great. Thanks. I found it at Summit Racing for half the price of ACS if anyone is interested.

BTW, I have had queries about the the fact that it LOOKS like my aft fuel supply tube is angled up coming out of the tank. I assure you it’s not. It’s an illusion created by the angle of the camera to the plane of the bend. I appreciate people verifying this with me.

[svyolo]

Summit and some of the other racing sites have some very unique parts for sale, especially plumbing. I found a -8AN O-ring plug fitting, already threaded for 1/8 NPT to use as a sump drain/water drain for my header tank. Sometimes the price is lower than the aviation sites, sometimes the same or higher. They tend to be out of stock less than the aviation sites.

[rodsmith]

Summit and Pegasus Racing have much nicer weldable bungs/fittings if you are building your own fuel tanks. Wish I had known that when I built mine. Used their weld on tubing fittings when making a modification.