Edwin,

I added some balsa triangle stock/fiberglass/epoxy between the firewall and the fuse. I am using a YS 120 air chamber, so I was at first concerned about the fuse holding up to the torque that this engine is capable of producing. I strengthened it before I ever flew the plane, so I cannot say whether there would have been problems. No problems thus far.

I think that it never hurts to strengthen the firewall/fuse junction.

Good luck with the spit.

Noah