Will,

I made a half rib similar to all the structural ribs expect 1/4 foam.  Regular MS hinge makes up the slosh bay doors(see photo).  During flight testing, I couldn't get the engine to hick-up during pretty violent yaw inputs with less than a gallon of fuel left (in one tank).  
Chris

 

 

 

Chris Zavatson

N91CZ   

360std