Problems with Dansk 356A Muffler

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Dave Erickson
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Problems with Dansk 356A Muffler

#1 Post by Dave Erickson »

Discussion of Dansk has gotten quiet here the past few months, but the problems remain. They are the only maker of a 356A muffler, so I ordered one from Zim's. It is a piece of garbage, there is no way to make it fit without cutting it apart and rewelding it. The problems are multitude: the bottom pipes are not parallel, cocking the muffler lower on one side; the upper flanges do not line up with the head exhaust ports, there is no way to get them on the studs, they are 8mm too low on one side and 11mm too low on the other side. The upper flanges are not perpendicular to the heads side to side so even if I got it on there would be 2-3mm gap on one side of the flange.

I have a good used Leistritz from a C, but I was told it would cause clearance problems on an A. I think I am going to try it and see if I can return the Dansk. I still have time to cut the Dansk apart and reweld it, so my main concern is whether putting the Leistritz on the A will cause problems. Opinions and experience with this would be a big help.

Here are some photos:
IMG_0577.jpeg
IMG_0578.jpeg
IMG_0583.jpeg

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David Jones
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Re: Problems with Dansk 356A Muffler

#2 Post by David Jones »

Check Eisenmann mufflers out of Germany. Expensive maybe but not in the long run.
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Martin Benade
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Re: Problems with Dansk 356A Muffler

#3 Post by Martin Benade »

I think the C one is too wide.
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Dick Weiss
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Re: Problems with Dansk 356A Muffler

#4 Post by Dick Weiss »

Dave,

There are times the #1 & #3 pipes can be aligned using a rubber or leather mallot, but if the flanges won't fit flat
to the exhaust ports, that's a definate problem, The same goes to the exhaust #2 & #4 pipes into the muffler.
Also, the Dansk originally had 40mm ID entrys into the muffler and the original 38mm pipes (on the heater boxes)
required a sleeve/shim so the clamps would close the pipes preventing exhaust leaks.
Later mufflers were changed to 38mm (1-1/2"), unless if some leftovers still still exist.

As mentioned by other members, the best/correct 'stock' mufflers are made from Germany altho a little more costly.

Dick

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Re: Problems with Dansk 356A Muffler

#5 Post by Dick Weiss »

Dave,

I forgot to mention that a B/C muffler is 3" wider vs the A muffler and due to the underside of the tail structure,
it Won't Fit!
I once had an A car w/one and wondered how it got jammed in and I had a hell of a time to get it off!!!

Dick

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Re: Problems with Dansk 356A Muffler

#6 Post by John Brooks »

You need a good straight edge, a machinist square a couple good clamps and a torch. Clamp the straight edge to one side, and bend to suit. You need to heat and bend a pipe and get it to align with the head. Be sure to keep the bolt holes in the same plain, parallel and square. It should slip over the studs with no strain on the head studs. The flanges should be parallel with the heads vertically and horizontally and fit . Don’t relay on a gaskets or the bolts to stretch a poor fitting muffler in place. Repaint the heated spot with a couple coats of high temp paint.
The best one I have ever seen was a hole and a half out. Big 18-24” crescent wrenches will fit across the flats on the flanges to twist, port-a-power to spread. You can fix it, and make them fit, but you should not have to.
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Re: Problems with Dansk 356A Muffler

#7 Post by Jules Dielen »

And after all the bending, tweaking and stetching they last a whopping 500 miles until they crack at the welds to the muffler. Garbage is right.
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Re: Problems with Dansk 356A Muffler

#8 Post by Dave Erickson »

Dick Weiss wrote: Fri Jul 22, 2022 11:02 pm Dave,

I forgot to mention that a B/C muffler is 3" wider vs the A muffler and due to the underside of the tail structure,
it Won't Fit!
I once had an A car w/one and wondered how it got jammed in and I had a hell of a time to get it off!!!

Dick
Dick, thanks, those are the details I needed. I guess I have no other option but to fix the Dansk. I wish Stoddard would go to Eisenmann and get them to make the full line of 356 mufflers.

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Re: Problems with Dansk 356A Muffler

#9 Post by Dave Erickson »

John Brooks wrote: Fri Jul 22, 2022 11:42 pm You need a good straight edge, a machinist square a couple good clamps and a torch. Clamp the straight edge to one side, and bend to suit. You need to heat and bend a pipe and get it to align with the head. Be sure to keep the bolt holes in the same plain, parallel and square. It should slip over the studs with no strain on the head studs. The flanges should be parallel with the heads vertically and horizontally and fit . Don’t relay on a gaskets or the bolts to stretch a poor fitting muffler in place. Repaint the heated spot with a couple coats of high temp paint.
The best one I have ever seen was a hole and a half out. Big 18-24” crescent wrenches will fit across the flats on the flanges to twist, port-a-power to spread. You can fix it, and make them fit, but you should not have to.
John, I had something like that in mind. Nice graphic description of how it is done. Wish I had a utube video of it!

Actually I am going to try this approach, let you know how it goes:

1. the 2&4 pipes would fit the studs if the lower pipes were re-aligned. The main problem with 2&4 is that the flanges are not in the same plane. So first step is to mill the flanges into one plane. They are thick enough to make it work.

2. Cut the reinforcing gussets on 1&3 and see if they can be bent into alignment. If not, cut 1&3 off the muffler, install the muffler then reweld 1&3 in proper alignment.

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Re: Problems with Dansk 356A Muffler

#10 Post by Peter Silten »

Dave, I assume you are trying to fit the Dansk muffler to your D. I have a Dansk on my D that was installed several years ago without any issues. I wonder if the one you got was defective. I also assume that you contacted Zim's to complain about the muffler. If so, what did they say?

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Re: Problems with Dansk 356A Muffler

#11 Post by John Brooks »

Dave

No need to mill the flanges, when the pipes are red hot they are pretty malleable. I used a hydraulic port-a-power to spread them. A pair of big crescent wrenches to align the flanges. I used a acetylene spud torch to heat up 2-3” of the pipe. Bend it around, then flange down to verify the parallel and square. I have a couple brig straight edge’s, I use them and a feeler gauge to get both sides equal after the holes like up.

Worried about weld cracking, just re TIG them. I think someone at the factory ran over the welding assembly fixture with a truck and did not tell anyone. They look good out of the box, they are just off 5-10mm.
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Re: Problems with Dansk 356A Muffler

#12 Post by Dave Erickson »

Peter Silten wrote: Sat Jul 23, 2022 1:17 am Dave, I assume you are trying to fit the Dansk muffler to your D. I have a Dansk on my D that was installed several years ago without any issues. I wonder if the one you got was defective. I also assume that you contacted Zim's to complain about the muffler. If so, what did they say?
Peter, yes it is for the D. I needed the muffler for 356A with the US bumpers with exhaust cutouts. Dansk also makes a sport muffler with attached tailpipes that go under the bumper.

Mine has the smaller dia. pipes that are a good fit to the 1&3 pipes. I haven't contacted Zim's, but I'm in a hard spot here. I need the muffler to fit and I am picking up the car at AI in two weeks, then installing the motor, no time left to fool around, so I will just make the Dansk muffler work.

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Re: Problems with Dansk 356A Muffler

#13 Post by Jon Schmid »

Jules Dielen wrote: Sat Jul 23, 2022 12:12 am And after all the bending, tweaking and stetching they last a whopping 500 miles until they crack at the welds to the muffler. Garbage is right.
10-4, Jules. I am on my third Dansk muffler for my 356C coupe and the problems have never been fitting them (or maybe it was...) but the Godawful cracking everywhere where the pipes enter/exit the can. After several "rewelds," I finally had a muffler shop guy weld some "flying buttress gussets" from the can to the pipes and the cracking problem went away. Now, the can itself has developed holes. For what they charge, Dansk makes a very sh*tty product and gets away with it because they think that they are the only game in town. I hope that changes soon--I don't want a Bursch type exhaust system on my car unless I have absolutely no choice. No knock on the Bursch products, I just like "stock" looking units...

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Re: Problems with Dansk 356A Muffler

#14 Post by Dave Erickson »

The problem just got a lot worse. Since its Saturday I cannot contact Zim's, hopefully I can get this fixed in the shop. The muffler was assembled from mismatched parts, that is why it does not fit. The pipes for 3&4 are an inch and a half shorter than the pipes for 1&2. The length difference appears to be entirely in the straight section between bend and expanded tubing or flange. I didn't see it when I had the muffler out in the shop, but once I set it on the milling machine table it became obvious. Here are some photos:
IMG_0591.jpeg
IMG_0592.jpeg
IMG_0595.jpeg
IMG_0596.jpeg

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Re: Problems with Dansk 356A Muffler

#15 Post by Martin Benade »

That’s necessary because the heads are offset about that much.
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