Question for Ken Cook and any one else with an opinion

Fred, there's a lot of information to be heard from myself and also required from you. For starters, I will probably end up with carpal tunnel if I type all of your requested info. I will be brief as possible. Just for the record I have little patience for stuff that doesn't work. This is why I investigate inside to insure against stupid problems that consume my valued time. Those who don't take things apart, they will some day. There's really not a whole lot to say about a Ring. Personally, I feel you will have more than enough fly time with 3.5 ounces. That being said, A Brodak BH-597 is my choice. This fits on the nose with enough room. It also has it's fuel pickup under the tank allowing a straighter shot to the needle valve and a piece of fuel tubing less than 2" long. I use muffler pressure with this tank over uniflow. I don't use uniflow on the Fox due to vibration problems, that's just me though. A chicken hopper could be substituted and I've seen these work terrifically on the Ring with a Fox .35. I like Hopper tanks, I hate fixing them cause it's a major pain in the rear end. If the hopper is your choice go to Eric Rule and get the GRW. Buy any other and your going to regret it.

The Brodak tank has ribs to stiffen the metal on the BH-597 deep wedge. Due to flexing from rubber bands over the tank and repeated filling I've seen the tank crack directly on these ribs. It won't happen immediately, it probably will though at some point.

As for tanks, 1" high tanks typically 2" wide are sized by length. If you have a 4" tank, you have a 4 oz. tank. The T-28 was a common tank. Brodak catalog probably and more than likely cross references Perfect and Veco size tanks. A MK VI is going to be extremely heavy on the nose of a Demon unless you make a long boom version. If this is a Blackhawk kit, your going to fold the plane on it's first flight out unless you redesign it as the MK VI is 4 times more powerful than the engines of the period. A tank could be made to fit, but it will probably be sticking out of the wing. This means making tank fairings around it. A tank may fit, but I don't generally use tanks in wings due to them being problematic. When I say problematic, I mean fuel feed issues in hard g maneuvers.

Any Mongoose I ever flew or witnessed had a chicken hopper on the nose. A GRW 325C is exactly 2 3/8". Shave a flat on your leading edge, sink the tank into it a bit and glue a piece of 1/8" ply on the engine side of the tank. Best Mongoose tank you can have. Extend the fill and also the uniflow pipes by using fuel tubing about 1 1/2" long and leave them rest directly on the cylinder head. It gets the pipes into cleaner air due to the cylinder head causing turbulent air as it spills over the cylinder. Remember, when you set your needle, you don't do it conventionally like a stunt model on it's gear. Pick the plane up nose high and cocked outboard of the circle. Peak the engine and then needle it back to where it's bouncing in and out of a wet two.

        The problem with hard tanks in a wing are the fact that commercial tanks generally have the fill on top and overflow on bottom. You can't have pipes hanging down on a wing as you will damage them and the tank needs to be reworked. A Brodak A.T.F. tank can be modified to work but this is what you didn't want to do. Probably the only tank that would've fit the Voodoo properly and work properly was the Veco pressure tanks. They were just nice tanks. Similar tanks could easily be made and this would take a little homework on size but if need be, I could build that tank for you if you provided me with the basic tank. If you do find a Veco tank like mentioned, it more than likely is corroded to hell inside.

    I always suggest standard vent to most people. This doesn't suit many, but it's the easiest and it's  a no brainer to figure out. As their skills improve, I suggest moving onto uniflow. Seeing your list of planes here, I don't see the apparent need for uniflow but if your satisfied with runs that lean out throughout the flight, stick with standard vent. That being said, a uniflow tank can be run in standard configuration, muffler pressure, uniflow to the atmosphere. You have 3 choices in one tank. It's entirely up to you .