VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #1  
Old 04-14-2022, 12:49 PM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,764
Default Muffler Crack...

I'm doing Annual Condition Inspection now and found a crack in the muffler where the exit exhaust tube is welded on. Looks like vibration induced metal fatigue from long cantilever exhaust tube. TT=750. Muffler is in back of car and headed for local TIG welding shop...
-
Attached Thumbnails
Click image for larger version

Name:	Screen Shot 2022-04-14 at 2.36.37 PM.jpg
Views:	174
Size:	179.7 KB
ID:	24643  
__________________
-
Jim Stricker - EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 790

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father - CFI) - USAAF 1st Lt. Captain B-17H
Reply With Quote
  #2  
Old 04-14-2022, 09:20 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 3,302
Default

Jim,

Thanks for posting. Iím in annual now and will take a close look tomorrow. Iíll post my results (about 1250 hrs total).

Rich
Reply With Quote
  #3  
Old 04-15-2022, 07:01 AM
Walt's Avatar
Walt Walt is online now
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,723
Default

In the certified world, some exhaust system manufacturers double their warranty if you have the prop balanced, vibration causes cracking.
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 2000+ hrs, New Titan IO-370, Bendix Mags, MTV-9 prop
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
Reply With Quote
  #4  
Old 04-16-2022, 09:01 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 3,302
Default

Checked mine today. No crack! Maybe the Thunder gods are displeased with you, Jim!
Reply With Quote
  #5  
Old 05-21-2022, 07:31 PM
Tony_T's Avatar
Tony_T Tony_T is online now
 
Join Date: Dec 2008
Location: Lacey, WA
Posts: 1,459
Default Crack found

Started my annual today. After reading Jim's posts, the muffler was high on my list. Found a pretty nasty crack, almost 180 degrees around the exhaust tube the exits the muffler and also extends into the muffler body just like Jim's. An experienced welder here thinks it will be an easy fix. If that doesn't work out, I guess I will be looking at the new EX-00044 exhaust system. Airplane has 690 hours, my prop has been dynamically balanced from early on.
Attached Thumbnails
Click image for larger version

Name:	IMG_3416.jpeg
Views:	83
Size:	893.0 KB
ID:	26056  
__________________
Tony
E-LSA RV-12 ULS

Last edited by Tony_T : 05-22-2022 at 08:23 AM. Reason: Added airplane hours.
Reply With Quote
  #6  
Old 05-21-2022, 09:31 PM
seagull seagull is offline
 
Join Date: Dec 2019
Location: Highland, CA
Posts: 510
Default

Jim, Tony, have either of you had to replace muffler springs, if so how often?

I wonder if the vibrations that are getting to the muffler to cause the cracks are the same that cause spring breakage / wear. I remember reading on here someone had the bell sockets on the muffler wear, another sign things are moving around.
__________________
Live as if you were to die tomorrow. Learn as if you were to live forever.
-- Walt --
Reply With Quote
  #7  
Old 05-22-2022, 08:26 AM
Tony_T's Avatar
Tony_T Tony_T is online now
 
Join Date: Dec 2008
Location: Lacey, WA
Posts: 1,459
Default

Walt
I have never had a broken muffler spring. I did replace all the springs about 300 hours ago, just because.
__________________
Tony
E-LSA RV-12 ULS
Reply With Quote
  #8  
Old 05-22-2022, 08:59 AM
seagull seagull is offline
 
Join Date: Dec 2019
Location: Highland, CA
Posts: 510
Default

I am at 930 hrs and inspected my muffler because of the cracks you and Jim found. Mine isn’t cracked, yet. I have never broken a spring but 4 were worn 1/2 way through on the spring, the muffler hooks were fine. I replaced all 8 with the stainless ones from Spruce.
__________________
Live as if you were to die tomorrow. Learn as if you were to live forever.
-- Walt --
Reply With Quote
  #9  
Old 05-22-2022, 09:22 AM
jrtens's Avatar
jrtens jrtens is online now
 
Join Date: Apr 2018
Location: Utah
Posts: 278
Default

Quote:
Originally Posted by seagull View Post
I am at 930 hrs and inspected my muffler because of the cracks you and Jim found. Mine isnít cracked, yet. I have never broken a spring but 4 were worn 1/2 way through on the spring, the muffler hooks were fine. I replaced all 8 with the stainless ones from Spruce.
Since you would rather replace springs than muffler hooks, perhaps stainless steel is not the way to go?
__________________
Jon
2019 12iS SLSA
Salt Lake Int'l
Reply With Quote
  #10  
Old 05-22-2022, 09:43 AM
seagull seagull is offline
 
Join Date: Dec 2019
Location: Highland, CA
Posts: 510
Default

Quote:
Originally Posted by jrtens View Post
Since you would rather replace springs than muffler hooks, perhaps stainless steel is not the way to go?
That very thought came to mind, I am not sure which would wear faster. Sometimes the softer material takes on surface grit and wears the harder material. I believe the original springs were high temper steel. They should have been harder than the hooks especially after annealing from the welding. I will watch these to see which side is wearing.
__________________
Live as if you were to die tomorrow. Learn as if you were to live forever.
-- Walt --
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 08:44 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.