Marko Bewersdorff <marko@bewersdorff.com> wrote:

> what are the staright through mufflers like? how much do they weigh and what
> is their size, source, life expectancy etc.
> any pictures?

   The problem with most "straight through" mufflers is that, at the short header length we're using in aviation, the packing material (usually fiberglas or steel wool) - which acts as a "baffle" around the perforated core of the muffler - is quickly overheated and either burned up, or blown out.  Special materials, e.g. 321 stainless, are needed.

   Nevertheless, Burns Stainless has an interesting looking product:

http://www.burnsstainless.com/UltraliteMuffler/ultralitemuffler.html

Dale