Hi Ed,
I have removed the blade and replaced it with a spare new one I had from my 3 blade configuration.
I'll make another exhaust, but with thicker tube.. Last one was too thin and as you said it vibrated the welds untill they failed. The good news is that I just got a job across the road from my hangar. I'm a desk driver at aircraft exhaust overhaul facility.
Buly

From: "Ed Anderson" <eanderson@carolina.rr.com>
Date: 2006/09/06 Wed AM 07:57:30 EDT
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: [FlyRotary] Departed Exhaust

Hi Buly, great to hear about your flight and happy to hear the missing
exhaust component did not cause damage - however, I would inspect the prop
blade very closely to make certain no small cracks in blade - particularly
near the hub.

 Yes, I have pulverized sufficient metal by trying different exhaust
internals to say that the shock of the exhaust pulse particular with a turbo
block is tremendous.  I have destroyed 1/8" thick stainless steel in a
matter of hours.  It appears that if a exhaust component is perpendicular to
the front of the shock wave, the impact on the component is such to reduce
its life to almost nil.  If the component is at an angle then its life is
much longer.  The constant flexing of the metal at 200 times/sec at 6000 rpm
caused by the strong exhaust pulse fatigues the metal extremely rapidly.

 The joke around my airport is "You can hear Ed long before you can see
him!"  - my response is that its a safety feature to let others know I am on
my way inbound{:>).

Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
----- Original Message ----- From: "Bulent Aliev" <atlasyts@bellsouth.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, September 06, 2006 7:17 AM
Subject: [FlyRotary] Re: OT: Gardenhose as level


> Joe, it was a "shake down" alright with an exhaust problem like yours.
> on Sat we did some takeoffs and landings with the CFI Ron Miller.  With
> gross weight of 1850 pounds, on takeoff I'm getting 6500-7000  rpm and
> climb rate of about 1000 fpm. Than we went to 1500 ft over  the airport
> and i did some steep turns etc for about 40 min. It flies  like a dream
> (compared to C-172 :). Transponder did not work again.
> Next day we got a waiver for the transponder and headed to an old
> uncontrolled military field with two huge 5000 ft runways, so i can
> practice landings and takeoffs. So we took off and headed for our
> destination at 3500 ft over alligator country. Pulled back the power > to
> 5000 rpm and we were cruising at 140 knots. Nothing spectacular,  but i
> kept the prop at low pitch to go easy on the engine. 15 min   later, we
> heard a bang and the plane felt like we run over a rock.  First > reaction
> look for a place to land. But soon everything checked  out and the > engine
> kept running normal with temps at 185-187F degrees  with OAT at 85F.
> Landed OK at our destination and taxied to the FBO.  Ron got out first > and
> started looking, but can not find anything  wrong? I got out and > noticed a
> slight scuff like a drag mark 3" wide  on one of the Ivo blades > starting
> about where the exhaust would be  and going to the tip. The las oval > piece
> of my shiny new exhaust was  missing. Mystery solved. Ivo is a one > tough
> prop to survive a 3" long  3" diam. SS pipe going hitting the blade. > We
> continued with the  training and I was getting good at it but with lots > of
> full power  takeoffs and not enough time for the engine to cool down, > some
> of the  coolant boiled out on takeoff and we came down to replace to > add
> more  coolant and check under the hood. Added some water, cleaned the
> plugs, just in case and took off again.
> By now it was a sweltering heat with jungle like humidity and after > few
> landings, we headed home. The trip was uneventful, the engine was > running
> fine around 5000 rpm. The biggest surprise later was after I  removed > the
> SS heat shields from around my new exhaust pipes. one  pipe was totaly
> separated at the weld, another was half cracked.
> Sound familiar Joe:) The exhaust pulses must be ferocious? people on > the
> ground said they can hear me long before they can see me coming:)
> More later. Got to go to work.
> Bulent "Buly" Aliev
> FXE Ft lauderdale, FL
> http://tinyurl.com/s5xw8
>
> On Sep 5, 2006, at 11:47 PM, Joe Hull wrote:
>
>> OK - it's supposed to be "Shake down cruise" - don't tell me you >> broke
>> down
>> somewhere!!
>>
>> But congrats on flying it anyway!!
>>
>> Joe Hull
>> Cozy Mk-IV N31CZ (65 hrs - Rotary 13B NA)
>> Redmond (Seattle), Washington
>>
>>
>>> -----Original Message-----
>>> From: Rotary motors in aircraft  [mailto:flyrotary@lancaironline.net] >>> On
>>> Behalf Of Bulent Aliev
>>> Sent: Tuesday, September 05, 2006 8:20 PM
>>> To: Rotary motors in aircraft
>>> Subject: [FlyRotary] Re: OT: Gardenhose as level
>>>
>>>
>>>>
>>>> Guess I need to buy some expensive clear hose .....
>>>> Finn
>>>
>>> Finn, if you buy the right size, one day you can used for your fuel
>>> lines on the next airplane. Worked very well on the first one :)
>>> Buly
>>> Finally checked out in my plane.
>>> Did my first 100 mile "cross country". Or should I say "break down
>>> cruise" :),
>>>
>>> --
>>> Homepage:  http://www.flyrotary.com/
>>> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>
>>
>> --
>> Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>



--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/

--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/