I tried the Edelbrock RPM series on my plane.  It lasted about 20 hours
before self destructing.  Packing (ceramic) blew out in about 5 hours. I
sent pictures of it to the list some time ago.
Tracy Crook

How about Inconel-718 turnings off a lathe? They are a bit stiff and can cut skin
to the bone instantly but if packed into a casing should work.

Blake

Blake,
I assume that you mean that the Inconel-718 would be used for muffler packing.  What about the rest of the muffler.  Tracy stated that the RPM series muffler self destructing in 20 hours.

Wouldn't it be best to just make the entire muffler from Inconel?  I know that this stuff is ridiculously expensive but I don't want my muffler self-destructing into my pusher prop.   Every time I consider using 316-SS instead of Inconel, I remember all the stories about Tracy's mufflers being destroyed after relatively low hours.  My problem so far has been finding a supplier for Inconel tubing and sheet that is willing to sell in the small quantities we need for building our mufflers.  I've been looking for nine months without any real success.  Most suppliers that are willing to sell to individuals want to sell full sheets and uncut lengths.  The last I figured, I would have to buy about $2000 worth of Inconel and would only use about one forth of it for my system.  Is there anyone else out there who wants to build their exhaust system from 600-Inconel ???  If so, this is a product that would definitely be best to buy in a quantity group purchase.  If anyone knows of a good supplier and / or would be interested in participating in a group purchase........let me know!!!
Thanks,
Don Mitchell
Plano, Texas
Standard Fixed Gear Velocity (~70%)
Mazda 20B with T. Crook EFI / EI / Redrive
N 6 V V (Reserved)

Don, not to worry. 
Just go up a bit on the muffler wall thickness made from stainless steel.
Ed Anderson's SS pipes are quite thick and they don't even discolor.
They show signs of lasting forever. As I recall they are .065 thick.
I forgot for sure Ed. How thick are they?

Tracy's original .035 thick SS  muffler under the cowl lasted 
600 hours. Tracy's original muffler is on the left and what was
left of his Eldebrock muffler on the right. 

I would guess that a .050 thick SS muffler should last ten years.

Paul Lamar

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