Actually a 30-cell pac would do it. Hmm. Use 230 size motors on an all-foam \ competition balsa rig.... vacuum-bag with .2oz c.fiber... If you could keep the weight down it'd really move out. For about 3 mins. LOL. I rather think it'd be more practical to use 4 brushless motors with a single ducted fan, one for each engine 'pod'

Just some thoughts.