This will not be the type of answer you want!
I can just say that the rocket makes more draft when the heat goes off at the top of the oil drum, because the less hot heat goes down.
So if you have a mass there...
I have read before that this is not a good idea.
I miss the old days when I would think up a sinister scheme for world domination and you would show a little emotional support. So just look at this tiny ad:
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