Fuel tank 'clunk" question

What he said is correct, and another point that could be made is to use a big enough fuel tank that you don't burn more that 2/3rds of the tank on a normal flight. That is usually enough to keep it running.

Another choice is to use a header tank. You have your 12 oz or whatever tank feed into the vent of a 2 oz tank, then into the carb. The small tank never leaves full until the big tank sucks air.

-- Jim in NC

P.S. Don't let that clunk go to the front of the tank. The bend will cut off the fuel flow.

Hopefully you won't be in a full power dive long enough to use all the fuel in the line!

Jim, You definately don't want the clunk to go to the front of the tank. If you are in a dive long enough to empty the fuel line you will be taking a trip to China to find yr plane...In fact you should take steps to prevent it, as it may go to the front in a hard landing and give you all sorts of grief feed wise. There are two ways to do this: 1. Slip a length of spring over the pickup tubing so it can't bend forward. 2. Where the copper/brass tubing exits inside the tank only use a piece of fuel tubing that is about

I think that you will really like the plane. Good luck with it. Gord Schindler MAAC6694

Jim

Thanks to all that replioed to my question...The tank is installed and fuselage is sheeted over...I did put the tank in on a bit of an upward angle though just to set my head at ease.... Thanks again to all that replied....a very knowlegable group!...Jim

copper/brass

You all are forgetting that in a dive, if the dive is faster than fuel can free fall, the fuel will remain at the back of the tank. Most all manuvers will keep the fuel at the back.

Dan Thompson (AMA 32873, EAA 60974, WB4GUK, GROL) remove POST in address for email

Indeed you are right. In fact, in almost all except inverted flight, the fuel doesn't move. There is a marvelous video taken from the back seat of an Aero Commander, over Bob Hoover's shoulder as he pours a glass of water from a pitcher while doing a roll. The glass is sitting on the top of the instrument panel. He then proceeds to put the A/C through the most amazing sequence of manouvers and the water never moves. Of course, we are not likely to be as co-ordinated in our flying as he is but it makes the point. Gord Schindler MAAC6694

The Aero Commander is NOT rated for much negative Gs. All the flying he did was ALL at positive Gs. We modelers quite frequently pull significant negative Gs.

David

You have to be accelerating faster than the acceleration of gravity for that to be true. In a 15 second dive, you would add 32 + 32 .... fifteen times and that would be your vertical speed in feet per second. That would only keep[ up with gravity.

.. Thanks in

-> Felt clunc!

I think a 24 oz tank is too big for a .91. The fuel draw may not be adequate when the clunk is so far from the engine, due to the size of the tank. 14 oz would be more realistic, unless you have a pump. (now I'll go back and read the original post again to check on that).