ORIGINAL: Lnewqban
Very interesting post, Roguedog!
For tanks located way off the centerline of the spray bar, the attached schematic shows how the influence of the height of the fuel reverses for each case.
If the loop is tight enough to generated 2g's of acceleration, the weight of the fuel doubles.
The outside loop may put more static pressure on the spray bar, making the mix too rich for steady idle.
An uniflow layout may be a good solution in this case:
http://www.fraserker.com/heli/uniflo...flow_works.htm
You forgot to deduct the muffler pressure lostin the outside loop.Because the muffler vent is at the top it is reduced by the head of the fuel. With this arrangement the correct tank placement is with the center line of the tank below the spraybar. But usually less than 1/2 inch.