ORIGINAL: kargo
Again, thanks to everyone for their help.
Another one of the reasons I used the header tank setup was the difficulty the cap of the fuel tank at an acceptable height relative to the motor. I've read this should be no more than half an inch below (and I know I'm not using the right term here) the fuel intake on the motor. The instructions used an 8oz tank and I of course wanted a lot more than that. The instructions (see link) show an 8 oz tank tucked right up against the stringers for the nose, its back end right up against the 1/4inch cross piece (step 64 picture 62). The space is really limited unless you cut out that cross piece like you do in step 61 picture 60 (they do this for sliding the tank in and out, with the header I didn't need to remove this).
Do you guys think I'll be able to get away with the motor an inch above the fuel tank cap? I might be able to mount the motor inverted or sideways and solve this issue. Any suggestions?
Thanks, Kargo
If you were going to run an 8 oz. fuel tank, having the fuel feed line exiting the centerline of the fuel tank up to three or even four inches below the carb's spraybar would probably work just fine. However, as we both know, that is not the situation that you are in.
The problem I see is with the 40 oz. fuel tank as it burns off fuel, or as you climb and dive the model. As stated previously, in other articles, your engine is using suction feed with no regulation other than that provided by the SIZE, SHAPE and LOCATION of the fuel tank. Your little Saito .72, while a fine engine, lacks the sophisticated carburetor/fuel system that your ultra long duration flights require.
Ed Cregger