Tracy,

Here is a picture of the inside of the HP II resonator.  It is different from the larger HP-2 muffer in that it only has one perforated cone, on the inlet.

 

Check out this page http://www.clubprotege.com/forum/showthread.php?t=28727  There are pictures looking into each end of the HP resonator muffler.  You can clearly see the perforated cone on the inlet side, also a tubular piece and a flat piece on the outlet.  There is also a perforated chamber around all of this, and some insulating material between that and the outer shell.  I suspect that the insulation will be short-lived.  Hopefully, it will continue to effectively muffle the rotary, even without insulation.

 

Mark S. 

 

On 1/10/08, Tracy Crook <tracy@rotaryaviation.com> wrote:

I didn't see the cutaway drawing you guys are talking about but my two HP-2 mufflers (I ended up putting one on the RV-8 as well) do not have any kind of packing material.  There are two 'nose to nose' perforated cones (one on inlet and one on outlet).   Flowmaster says there are also some "laminar flow baffles" in there but I can't see them without cutting the muffler apart. 

 

FWIW, I've tried many mufflers with packing material of all types and none of them held up for more than a few hours before loosing their stuffing.

 

Tracy C.

 

On Jan 9, 2008 3:27 PM, Mark Steitle <msteitle@gmail.com> wrote:

Ed,

The innards of the HP-2 Series appear to be different from the one shown.  The HP-2 has an entry cone, but the rest looks different.  I'm pretty sure that the HP-2 still uses some form of packing material.  
 

Mark S.