Cracked exhaust hanger

bruceh · #1 11-30-2019, 05:47 PM

I was doing an oil change today, and as usual, I give the entire engine a really good look over. I found one of the exhaust hangers had cracked.

The hanger is made from thinwall stainless steel 3/8" tubing. I know I can source this stuff locally, but making the end flattened looks like it might require some special skills/tools. I don't want to just beat it flat with a hammer. My vise is probably not sufficient to pinch this, and I don't have a hydraulic press.

Any tips, or should I just call Vetterman Exhaust and get a replacement?

Would you replace all hangers, or just the one that is cracked?

pitts flyer · #2 11-30-2019, 05:50 PM

I have 3 unused new ones. If you pay the postage via paypal and a bit extra for the paypal fee, I will send them to you.
Dave

Kyle Boatright · #3 11-30-2019, 05:57 PM

Simple to do with a vise.

Replace the broken one and fabricate a set of replacements to keep in your flyaway kit.

Steve Melton · #4 11-30-2019, 06:36 PM

I'm there at 800 hrs. Why did it fail? Was it connected to the engine or the somewhere else?

RussellT · #5 11-30-2019, 06:53 PM

As to why the hangers break, having just installed a new 4 pipe Vetterman exhaust I note the accompanying hand drawn installation instruction shows the hangers attached to the engine mount tubes with the flexible rubber section allowing for engine movement. I did not attach mine to the engine mount, instead I went to a sump bolt on each side still with the rubber tube coupler. It seems to me that an exhaust hanger fixed to the engine mount will always break even with lubricated slip joints and rubber coupling. My system seems well supported and I can't see any problems with it other than to ensure the tail pipes have sufficient clearance to allow for the engine movement. What do others do and think about the Vetterman mounting instructions?
Thanks,
Russell

Steve Melton · #6 11-30-2019, 07:15 PM

mine are attached to the sump and upon inspection 10 hrs ago they looked OK.

pilotkms · #7 11-30-2019, 07:16 PM

Bruce - hangers per plans seemed too ?slippery?. I used 1/16? steel straps 1/2? wide made from ACS stock for end supports. Then bought 1/4? exhaust hanging material from the auto parts store and made straps about 1? wide, to desired length. Use 1/4? holes thru the tire straps and the steel mounts. No issues in 440+ hours. EZ to check and see if they are worn or failing. Flexible yet solid attachment points.

Sam Buchanan · #8 11-30-2019, 07:28 PM

Here are the tubing swaging dies I made from aluminum angle to make a swage that isn't prone to stress cracks:

Put them in the vice and squeeze the tubing:

3/8" steel (not the soft, easily bent stuff) brake line purchased from the aviation aisle at the local auto parts emporium makes great exhaust hangars. I carry a pre-swaged and drilled piece in my flight kit for away-from-home replacement.

Steve Melton · #9 11-30-2019, 07:54 PM

Quote:

Originally Posted by pilotkms

Bruce - hangers per plans seemed too ?slippery?. I used 1/16? steel straps 1/2? wide made from ACS stock for end supports. Then bought 1/4? exhaust hanging material from the auto parts store and made straps about 1? wide, to desired length. Use 1/4? holes thru the tire straps and the steel mounts. No issues in 440+ hours. EZ to check and see if they are worn or failing. Flexible yet solid attachment points.

I flared my tubes slightly. no slip in 800 hrs.

Steve Melton · #10 11-30-2019, 08:19 PM

Quote:

Originally Posted by Sam Buchanan

Here are the tubing swaging dies I made from aluminum angle to make a swage that isn't prone to stress cracks:

Put them in the vice and squeeze the tubing:

3/8" steel (not the soft, easily bent stuff) brake line purchased from the aviation aisle at the local auto parts emporium makes great exhaust hangars. I carry a pre-swaged and drilled piece in my flight kit for away-from-home replacement.

that's better than a sharp corner