Joel Howard brought over 20 gallons of 100LL in 5 gallon graduated racing jugs. We filled the fuel tank with 18.5 gallons, which was about 1.5 gallons more than I expected it to hold, and is now the fuel tank’s official capacity. With the fuel tank filled, the fuselage chocked up at 30* and graduated cylinders ready at the carb inlet level, we were ready to time our rate of flow. With me on the fuel shutoff valve, stopwatch and clipboard to record times, Joel was keeping an eye on the fuel jugs and calling out when we reached gallon marks. The Corvair engine with a MA3 carburetor requires an 8.3gph rate of flow, or 1 gallon in <7.23m, in order to produce 100% power. We found that I could flow 16.5 gallons at a rate that was adequate for full power. The remaining 2 gallons will be considered unusable. I plan to put 5 gallons in the fuel tank and mark my fuel float indicator at that level as Empty/Reserve. This will indicate when I’ve reached the top side of a 3 gallon reserve. So what this all means is that I have 13.5 gallons of fuel to burn (2.5 hours in the Corvair that burns ~5gph), followed by a 3 gallon reserve (~0.5 hours) and 2 unusable gallons. Plenty long legs for a Pietenpol.