On 2/25/2011 2:19 PM, Raymond Lambert wrote:

I am about to put the fuel tank in my first wing. I have to weld a flange on it for the fuel return line. Anyone can tell me if a 1/4" fuel return line is large enough ????

Raymond

I recently purchased a Mallory brand regulator, & it actually specs the return line size, based on HP & return flow. IIRC, 1/4" was marginally adequate. If you haven't bought anything yet, why not go with 3/8"? If you later discover that 1/4" is good enough, a half-ounce threaded bushing, or the right (3/8"NPT to AN4) fitting gets you back to that size. Remember, (as Tracy pointed out in a recent post) some of the time over 90% of the fuel will get bypassed back to the tank.

Charlie