[p40fan]

I am putting a tuned pipe on a webra 80 through the interior bottom of the fuselage in my extra 300. Am looking for suggestions on how to insulate the radio and fuselage interior from the heat generated by the pipe. The fuselage is epoxy fiberglass. The pipe will exit at the bottom of the fuselage just back of the wing trailing edge. There will be some airflow through the cowl opening, firewall and opening at the pipe exit. Any ideas would be appreciated.javascript:emoticon('')
Confused

Actual heat insulation is not necessary if you do the following. Make a tube about 1/8" larger inside diameter than the largest outside diameter of the pipe. There should be an abundance of cardboard tubes around at this time of the year. Coat it with epoxy inside and out. Install this in the fuselage. The pipe will go inside this tube. Ensure that cooling air from the cowl inlets is directed down this tube. I do not know how you are supporting the pipe tail end, When I use this system I put three beads of silicone along the pipe. When cured I trim the silicone to make the pipe a slide fit in the tube. This holds the pipe in the centre of the tube thus ensuring that air passes all around it.

I have posted pictures of a cowling on another thread in this forum. Although the specific layout may not be appropriate for your application the basic principle is sound.

Ed S

[p40fan]

Thanks for the reply Ed. I think you solved my problem. Now all I have to do is get the wife to wrap my present and give me the cardboard tube.
Thanks
DennisT