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Engine basics => Engine set up tips => Topic started by: Jim Oliver on February 08, 2007, 05:49:04 PM
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Hi guys,
Some one please help me with the tank set up for my Score. The fuse is covered/doped, the bottom tank hatch cover not yet glued in place.
I will be using an ST 51 so will need 5.5 to 6 oz. of fuel. I would really like to use a metal tank and seal it in the fuse, never to be seen again. Probably not practical, at least until I have the tank height question answered.
I have been using metal uni-flow tanks, but have grown weary of the rich/lean problem when flying upwind/downwind. So, thinking about a straight suction set-up. With the suction set-up, how could I install plumbing so that both the fill line and the over flow line would exit the bottom of the fuse--will that even work?
I want to epoxy the tank hatch cover in place to gain a little strength in the nose, so would like to use a metal tank, but will use a plastic tank if necessary.
Help, please!!
Jim
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Hi Jim,
Do you still experience the lean/rich problem with muffler pressure hooked up? I have found it to basically eliminate the problem. (uniflow outlet not exposed to differences in "pressure")
Bill <><
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Bill,
Thanks for the response.
I was watching a Windy tape recently and he said that he used suction tanks to avoid this problem and also to have a little more power at the end of the flight for the vertical/overhead maneuvers. (I don't really want to run muffler pressure.)
Also, I noticed that several planes on the video had two pieces of tubing exiting the bottom of the fuse, just aft of the engine. I took those pieces of tube to be the tank vents. If that is correct, it would avoid having a tank vent exiting the top of the fuse--I like that feature.
So--- thought I would pose the question and see if I can learn something. Any thoughts, anyone??
TIA,
Jim
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Another thing that works well for me and my uniflow tanks is to make a restictor plug for the unflow tube .All this is doing is reducing the opening in the unflow tube to a 1/16" hole .This has virtually made the rich lean every lap thing go away. #^
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Hi guys,
Some one please help me with the tank set up for my Score. The fuse is covered/doped, the bottom tank hatch cover not yet glued in place.
I will be using an ST 51 so will need 5.5 to 6 oz. of fuel. I would really like to use a metal tank and seal it in the fuse, never to be seen again. Probably not practical, at least until I have the tank height question answered.
I have been using metal uni-flow tanks, but have grown weary of the rich/lean problem when flying upwind/downwind. So, thinking about a straight suction set-up. With the suction set-up, how could I install plumbing so that both the fill line and the over flow line would exit the bottom of the fuse--will that even work?
I want to epoxy the tank hatch cover in place to gain a little strength in the nose, so would like to use a metal tank, but will use a plastic tank if necessary.
Help, please!!
Jim
Hi JIM
I have a little trick I use that works well for many people, I use a very light barbed L-bend, Using a front facing uniflow or vent tube, you just slide it on with a piece of fuel tubing about 1\2 inch long, IT will make the tube face either straight down, straight outward, or straight up, all of the positions STOP the air from pressurring the fuel tank when you come into a hard blowing wind.
This work for me, much better than the restriction ,or any other method I have tried
I will try to post a picture later but it is a simple item and works very well, they are also very cheap, about 3.95 per pack and you get a nice little fuel plug too for the overflow vent.
and NO you can't run the uniflow vent out the bottom, fuel will siphon out that way
Regards
Randy
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I'll be using a Tettra "Bubbless" tank in my Score. It's like a hi-tech balloon tank, and the 7ox version slips right in. It's easy to "short-tank", so I can swap in most any engine I have to try out.