• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Check That Muffler

Another Univair muffler with 200 hours. 160 hp.
View attachment 20089

I think that I know what may be the cause of these cracks. Stainless tends to become brittle adjacent to a weld. This is more of a problem on exhaust systems when heat and vibration are involved. If, when being welded, the muffler was purged with argon this embrittlement would be minimized. The muffler manufacturer needs to change it's welding process to include an argon purge.

I have seen proof of this on a brand "C" entirely new installation firewall forward. One trip around the traffic pattern and pulling the cowl for a check found one exhaust stack broken nearly 100% around a weld. Sent it back for warranty repair which was done at great expense (another story). It failed again in less than five hours in the same place. Had a friend who is an expert welder repair it on the plane. He purged the inside of the pipe with argon while welding. It never failed again.
 
I recieved my new nicocraft (wallcolmonoy) muffler yesterday. Bought it from aircraftspruce. The muffler bale is welded in too low in this tailpipe aswell... Does not even enter the muffler body..
seems as all nicocraft muffler bales is welded the wrong way. The old muffler is at least 10 years old.
money back possible?

yes and please file a
Form 8010-4 - MALFUNCTION OR DEFECT REPORT
https://www.faa.gov/forms/index.cfm/go/document.information/documentID/186275

that will kill people...
 
Yes, that's what I thought too. With the bale installed this far down the tailpipe, loose pieces could get stuck both in the muffler outlet AND on the incorrect positioned wire bale. Will have a look at that form..
I wrote aircraft spruce a mail three days ago describing the issue, but haven't got any feedback yet.
 
Here is pictures of the new Nicocraft muffler. The bale is mounted quite flush with the muffler body wall.
I have got in contact with the manufacturer. Will be interesting to se the final result of this.
 

Attachments

  • image.jpg
    image.jpg
    114.3 KB · Views: 268
  • image.jpg
    image.jpg
    156.7 KB · Views: 284
  • image.jpg
    image.jpg
    152.8 KB · Views: 231
I got a new muffler from nicocraft! If I reposition the wirebail I will have two serviceable mufflers! ��
 
It takes me under an hour to do the J-3 muffler AD. Same thing on a 180 Super Cub takes me a week! I am assuming that the reason the aircaft came back from CC without the Sutton I installed over a decade ago is that the Sutton didn't fit the 180 engine.

So the owner is on notice - this is the last 100 hour inspection - now it is twice a year. Does the Hot Rod muffler fit the 180 hp CC mod?

I promise - I had less work involved in installing the Sutton than is involved in that AD inspection. It really cleaned up that engine compartment.
 
I blew out an Atlee HD muffler this time. Could barely see a crack looking through up the tailpipe. I decided to go with the Sutton exhaust that has no baffles, saves 2 lbs and frees up the back of the engine and keeps the heat off the firewall. Gets kinda warm in Texas in the summer.
20180218_164228.jpg

20180218_164236.jpg
 

Attachments

  • 20180218_164228.jpg
    20180218_164228.jpg
    47.3 KB · Views: 1,221
  • 20180218_164236.jpg
    20180218_164236.jpg
    73.6 KB · Views: 1,223
I blew out an Atlee HD muffler this time. Could barely see a crack looking through up the tailpipe.

That's why I went with the gutted hot rod muffler. Still looks like new inside. Makes up for the 2 lbs too.

Speaking of weld cracks tho. 900 hrs

KIMG0403.JPG
 

Attachments

  • KIMG0403.JPG
    KIMG0403.JPG
    31.9 KB · Views: 284
Are those pipes still bolted tight to the engine? If so it sure looks like there were some stresses in the installation.

I found a loose nut on the rear of that cyl about 100 hrs ago. also the pin in the muffler clamp was gone. I'm not blaming this on manufacturing .
 
It's amazing how fast a pipe will crack when the installation has some unseen stresses when the pipes are tightened. Once around the traffic pattern will do it. These can happen even with an experienced set of eyes is supervising the job.
 
Nowdays after all lessons learned from this thread, I allways check the proper installation of the Muffler bail. Last month, I found Another bail incorrectly welded by nicocraft. The bail is welded about 3/8" below the muffler body down the tailpipe..
So you guys running Nicocraft Mufflers, Check for the proper position of the bail! This is the third muffler from nicocraft that I have found this anomaly on!
 
01666ee26158cdb2aed3d43234da9e28.jpg



Sent from my iPhone using Tapatalk
 
Why I hang out here, though I fly behind a Rotax 912S...... you guys have a lot of fleet knowledge helpful to even a non Cub flier.

I currently have 2340 hours on my muffler, with zero issues, BUT, this thread will make me check things over more often, and "more better." Original heat muff also.
 
Yeah the exhaust system is almost allways in the need for a little "fix" here and there at every annual.
 
Why I hang out here, though I fly behind a Rotax 912S...... you guys have a lot of fleet knowledge helpful to even a non Cub flier.

I currently have 2340 hours on my muffler, with zero issues, BUT, this thread will make me check things over more often, and "more better." Original heat muff also.

Ha, I forgot about this..... At 2600 hours, I started hearing a rattling sound, turned out my muffler had shed it internals, thus the noise. A simple fix (new muffler, though in retrospect I could have repaired the old one with what I know now, the stainless can was fine, just the baffles needed replacing), and the heat muff was still pristine so I put it back on.
 
Tailpipe is welded to the muffler. Not hard to swing the engine. Should just take loosening the tach cable and removing the two right side engine mount bolts at the firewall.
 
Ha, I forgot about this..... At 2600 hours, I started hearing a rattling sound, turned out my muffler had shed it internals, thus the noise. A simple fix (new muffler, though in retrospect I could have repaired the old one with what I know now, the stainless can was fine, just the baffles needed replacing), and the heat muff was still pristine so I put it back on.

Do you still have that Swiss muffler? That seemed pretty neat.
 
After about 1700 hours the internal stainless mesh that holds back the muffler packing loosened up a bit, so instead of a perfect cylinder it was possibly contributing to excessive back pressure, so I took it off the other day. It goes off and on in about 3 or 4 minutes, real simple. Previous static RPM tests showed no discernable difference in power. 6 pounds including mount hardware though, back to the stock in cowl Rotax muffler now, for the time being at least.
 
Suziki, Yamaha, Honda, BMW, and other motorcycles have offered variable exhaust valve flappers for years....EXUP valves Some's for noise reduction but the main reason is adding or subtracting exhaust back pressure which can fill in engine torque dips at certain rpm's. I always wanted to try a manual valve in a common pipe collector to see if there's anything to be gained in a free flowing system at partial throttle.

Gary
 
Back
Top