David,

Diverters don't really pose an overheating issue. We've tested them and they works without robbing the engine of power either.

I would take a piece of aluminum tubing of the same or slightly larger diameter as the stinger, bend a smooth curve into it and then couple it to the stinger with narrower silicone tubing and tie wraps or small clamps. MK actually used to make these diverters and they came with hardware so you could just attach it to the pipe and you've be done. On occasion you'll find them for sale on the auction site. I bought some last year.

I would also build a balsa rectangular duct section inserted in a diagonal fashion through the fuse where the diverter would be housed. This sort of insulates the inner part of the fuse from the heat and you can finish it with the rest of the model for fuel proofness. It is only visible from the fuse bottom where the stinger exists as the top part is covered by the pipe tunnel.

David