First off I want to say that it hurts me to bash a supplier of parts. But in the interest of safety, I have to do this. I built my airplane with vetterman exhaust w/mufflers. Now at the moment I can't remember the cost of the mufflers, somewhere in the 500 to 800 dollar mark. Well if any of you remember I ran a thread that ran as: High egt on no. 1 and 2. In the last 3 weeks. I thought I found the problem with exhaust gaskets. Now it started out with 100degress hotter on egt with the peak on fuel setting going higher as well. Well my problem was irratic, would be there, than not. I went through everything a person could think of to find the problem. Than the problem got worse, now I have egt's over 1600 on 1 and 2(300more), 3 and 4 CHT's would go through the roof up to 420. egt on 3 and 4 just fine. CHT's on 1 and 2 ok, egt's through the roof. I also found that 1 and 2 were running real rich.
I went and did a pressure test and all cylenders were 76to78/80. I dialed the cam all fine. I pulled the rockers off the exhaust and found wobble up to .08 on all stems. I call bart and he says that that's pretty normal, that he has seen way worse and not cause a problem with high egt's. He says restriction in exhaust or timing. well can't have a problem with two systems on electronics. I go back to the hangar and just look at the engine. Than I follow the exhaust off the no1 it goes to no2 and than out the muffler. I say, you idiot, you dumm dumm. I huridly pull of the exhaust off the front of the muffler and look inside with my trusty light. OH MY GOD. Is all I could say. All the guts of this muffler is pushed to the back of the muffler and cut off the exit.
I call Larry. He says, get this, I've never seen this happen before, they usually brake apart and go out the end. Well I thought you bet, whatever, problem like this does happen to me. He tells me that I need to get the latest update done on my mufflers, call the place in CAL that does them for me. In fact just send them to him. I call this guy down in KALIFORNIA and he says the same thing, we never have had an exhaust plug up, they brake up and go out the back. Send them to me and we'll fix you right up, and OH these are normal wear items and it will cost 150 each to fit them with the new stuff. WHAT???? I just put this airplane in operation not even 2 years ago. I may have 460hrs but it's NOT my fault. I say ok.
I take my mufflers off and go back to the shop. I look inside and all the pieces on the left muffler are floating around inside, that would account for it happening one time and not the next. I knock the muffler on the floor and get the offending piece flat disc to the opening in front, no way this thing is comming out. So I fire up the cutting torch and cut it in two. I pull this out, than I get to the tube inside which is like a swiss cheese thing. I possision it and gut it with the torch. Fine and dandy I now have an expensive straight pipe.
I grab the still good muffler and there is no way to gut this thing out so I leave it. Now I have this thought, KISS(keep it simple stuppid) I no longer want mufflers, updated or not. Plus 300 on top of what I've paid already, I'm a little ticked to say the least. Not only that, I put myself on the line flying this thing with a plugged exhaust. It flew and if it wasn't for the Dynon ems I wouldn't have know it had a problem.
Anyway I put the mufflers back on the plane and flew it, wooohooo, what a difference, in fact it has never reached the speeds that I got and I still have the right side with an acting muffler. I guess I'll just have to go buy a straight pipe and replace it. Cuss, KISS is going through my mind at this point. The money originally spend, well safety is going to have to be paramount in this one I guess.
My advise to anyone running mufflers. Make your own AD and check these thing either every annual or 100hrs. What to check for, well cracks in the insides and make sure they look good. Mine rusted out and broke apart in big pieces. Good luck with your mufflers is all I can say.
I went and did a pressure test and all cylenders were 76to78/80. I dialed the cam all fine. I pulled the rockers off the exhaust and found wobble up to .08 on all stems. I call bart and he says that that's pretty normal, that he has seen way worse and not cause a problem with high egt's. He says restriction in exhaust or timing. well can't have a problem with two systems on electronics. I go back to the hangar and just look at the engine. Than I follow the exhaust off the no1 it goes to no2 and than out the muffler. I say, you idiot, you dumm dumm. I huridly pull of the exhaust off the front of the muffler and look inside with my trusty light. OH MY GOD. Is all I could say. All the guts of this muffler is pushed to the back of the muffler and cut off the exit.
I call Larry. He says, get this, I've never seen this happen before, they usually brake apart and go out the end. Well I thought you bet, whatever, problem like this does happen to me. He tells me that I need to get the latest update done on my mufflers, call the place in CAL that does them for me. In fact just send them to him. I call this guy down in KALIFORNIA and he says the same thing, we never have had an exhaust plug up, they brake up and go out the back. Send them to me and we'll fix you right up, and OH these are normal wear items and it will cost 150 each to fit them with the new stuff. WHAT???? I just put this airplane in operation not even 2 years ago. I may have 460hrs but it's NOT my fault. I say ok.
I take my mufflers off and go back to the shop. I look inside and all the pieces on the left muffler are floating around inside, that would account for it happening one time and not the next. I knock the muffler on the floor and get the offending piece flat disc to the opening in front, no way this thing is comming out. So I fire up the cutting torch and cut it in two. I pull this out, than I get to the tube inside which is like a swiss cheese thing. I possision it and gut it with the torch. Fine and dandy I now have an expensive straight pipe.
I grab the still good muffler and there is no way to gut this thing out so I leave it. Now I have this thought, KISS(keep it simple stuppid) I no longer want mufflers, updated or not. Plus 300 on top of what I've paid already, I'm a little ticked to say the least. Not only that, I put myself on the line flying this thing with a plugged exhaust. It flew and if it wasn't for the Dynon ems I wouldn't have know it had a problem.
Anyway I put the mufflers back on the plane and flew it, wooohooo, what a difference, in fact it has never reached the speeds that I got and I still have the right side with an acting muffler. I guess I'll just have to go buy a straight pipe and replace it. Cuss, KISS is going through my mind at this point. The money originally spend, well safety is going to have to be paramount in this one I guess.
My advise to anyone running mufflers. Make your own AD and check these thing either every annual or 100hrs. What to check for, well cracks in the insides and make sure they look good. Mine rusted out and broke apart in big pieces. Good luck with your mufflers is all I can say.
