On my Westbury Hunter which I'm building it has a fully ducted installation and a single walled pipe. The rear of the fuselage is completely sealed with a bulkhead at the rear of the engine bypass, so no cooling air can get into the rear part. Both my previous planes have been open installations which allows plenty of cooling air to flow through the fuselage.

I am concerned about heat buildup in the rear of the fuselage and causing damage. How do other fully ducted installations cope with the heat?

One option I have read is to cut some holes in the shape of the NACA inlets into the convergent section of the bypass to allow some excess air to vent into the rear fuselage around the pipe. I also believe that this may also improve the static thrust of the installation. Has anyone tried this?

Thanks

Paul