RE: BUSA 1/6 scale Pup
HAH! The bane of modeling WWI birds, those rotary engines made for very short noses.
I am working on a 1/3 Pitts Special with the same problem. I am putting the batteries up in front of the firewall.
The plane was nitro powered, and the engine was bolted to a small engine box. My motor needed to stand 2" off of that box, so I purchased 2" standoffs. But when I realized how much weight I was going to have to put in the nose to get it to balance, I changed plans.
I am making a bigger motor box that will house the batteries right behind the motor, under the cowl.