Working on the next generation of mufflers

[jimkemp 526]

There are a few out there but I haven't heard anything back about them , its hard to find tubing that is 1.450" id , best I can find is 1.525" id and that's not a direct fit to the 300 manifold , so I can build them but the buyer would have to make a some kind of spacer to make them fit on the manifold

[WVHillbilly520H 10,374]

11 minutes ago, jimkemp said:

There are a few out there but I haven't heard anything back about them , its hard to find tubing that is 1.450" id , best I can find is 1.525" id and that's not a direct fit to the 300 manifold , so I can build them but the buyer would have to make a some kind of spacer to make them fit on the manifold

I work for this brand exhaust company, you may try here to get the tubing...https://shop.advanceautoparts.com/p/walker-bendable-straight-tubing-47968/10205481-P ...    .060" wall thickness with 1.50" O.D. will give 1.38" I.D. stock and with one these...https://shop.advanceautoparts.com/p/kd-tools-exhaust-and-tail-pipe-expander-1-1-2-to-2-1-2-kdt2071/22988154-P... should get your desired I.D.

[1995 520H+96+97 937]

@jimkemp

Do you have a 520 muffler for a pattern?

[jimkemp 526]

20 hours ago, 1995 520H+96+97 said:

@jimkemp

Do you have a 520 muffler for a pattern?

No , I don't have one , if I did I could make also

[EricF 589]

Looking back in this thread, count me in for another vote for interest in Onan mufflers for 520's. Well, pretty sure a whole lot of 520 owners will be beating your door down for a good muffler if you have one...

"If you build it, they will come!"

Edited April 21, 2019 by EricF

[1995 520H+96+97 937]

@jimkemp

I have a new 520 muffler (have not test fitted). Looks the same as my 1995, 1996 and 1997 520H mufflers.

Also have a used (junk) 1988 520 muffler. Heat shield attaches to muffler is different. 

[oneroadkingman 53]

On 4/21/2019 at 7:07 AM, jimkemp said:

No , I don't have one , if I did I could make also

I have one that i can donate for the cause if u would like.

[oneroadkingman 53]

On 4/21/2019 at 7:08 AM, EricF said:

Looking back in this thread, count me in for another vote for interest in Onan mufflers for 520's. Well, pretty sure a whole lot of 520 owners will be beating your door down for a good muffler if you have one...

"If you build it, they will come!"

count me in also!

[peter lena 8,876]

i built one years ago with all stainless steel at work , i only used perforated  stainless inside for baffling, was very quiet due to metal wall strength , i might try to recover it for the magnum engine. your work looks good , we as a group would love to have a good muffler source . pete  

[jimkemp 526]

1 hour ago, oneroadkingman said:

I have one that i can donate for the cause if u would like.

If you want to send one to me I will try to reproduce it and send you the first one for free , I will pm you my address

[rk1953 4]

On 4/30/2019 at 9:16 PM, jimkemp said:

If you want to send one to me I will try to reproduce it and send you the first one for free , I will pm you my address

have you tried the new 520 muffler yet ?

[jimkemp 526]

19 hours ago, rk1953 said:

have you tried the new 520 muffler yet ?

I cant find a die for the tubing bender that will make the bends tight enough , to have a custom die built would be way too costly for me to do , the radius is 1 3/4" , most dies are 3 1/2 to 4"

[lynnmor 7,384]

3 hours ago, jimkemp said:

I cant find a die for the tubing bender that will make the bends tight enough , to have a custom die built would be way too costly for me to do , the radius is 1 3/4" , most dies are 3 1/2 to 4"

Can you come up with a print of exactly what you need?  I may be able to help.

[jimkemp 526]

On 8/27/2019 at 9:56 PM, lynnmor said:

Can you come up with a print of exactly what you need?  I may be able to help.

I really don't have a print of the die , but it has to be for 1 1/8" tubing with a 1 3/4" radius that can bend 90 degrees , the tubing bender I have is a woodward fab manual bender

[lynnmor 7,384]

So you need this with a much smaller radius?  I didn't really expect formal prints, just a sketch that shows dimensions and mounting holes.  Perhaps you could trace around your smallest tooling and then show the reduced numbers.  A few photos might help.  I do think this will be a tough bend job with that small radius.  I have a tool & die shop and am pretty much retired, my interest in this project is only to help members and possibly get stainless mufflers.

 

I do have a spent muffler for a pattern if you need it.

Edited August 31, 2019 by lynnmor

[J Rankin 0]

I am searching for a replacement for the Nelson muffler on my two C-195s.  I have an old rusted out one you could use for a prototype if you are interest

[WHX?? 49,486]

I have one of you muffs Jim so just using this thread to tell you yours seems to accumulate condensation when it sits. Its not a huge problem. It quickly goes away after a minute or less of run time. One just has to learn to lean to the left on a cold start to avoid a face full of it. It does sometimes deposit little black soot spots on the hood but washes away. More so of course with cooler weather conditions.  I don't know if others experience this. Other than that yours are great and I will be ordering another in the future. I just love the sound tho so I'll take a little soot for the team!

Edited September 4, 2019 by WHX24

[WVHillbilly520H 10,374]

On 8/31/2019 at 9:44 AM, jimkemp said:

I really don't have a print of the die , but it has to be for 1 1/8" tubing with a 1 3/4" radius that can bend 90 degrees , the tubing bender I have is a woodward fab manual bender

What about a "conduit" bender? ...https://bisedwardsironworkers.com/td90-1-125x3-edwards-tube-die-1-1-8-x-3-90.html?gclid=Cj0KCQjwwb3rBRDrARIsALR3XeaclLNGb9d_1CmPlfqLYTqzK6PQ7fIB3ydSY0Nd7nojDBaNN4K5fssaAnUtEALw_wcB

[jimkemp 526]

On 9/4/2019 at 11:39 AM, WHX24 said:

I have one of you muffs Jim so just using this thread to tell you yours seems to accumulate condensation when it sits. Its not a huge problem. It quickly goes away after a minute or less of run time. One just has to learn to lean to the left on a cold start to avoid a face full of it. It does sometimes deposit little black soot spots on the hood but washes away. More so of course with cooler weather conditions.  I don't know if others experience this. Other than that yours are great and I will be ordering another in the future. I just love the sound tho so I'll take a little soot for the team!

I'm glad you like it , I know I made the mistake of my C120 got caught out in the rain and the pipe was pointed  the right way for the rain to go right in , after the rain storm I went out to get the tractor back in the barn and when I fired it up I got covered in black , wet soot , not sure what to do about condensation in the muffler , I haven't heard any one else say anything about that , I don't think I can put a hole in the bottom as that would let exhaust out , Sorry if its getting the hood dirty , maybe I can send a free cleaning towel with every muffler for cleaning the hoods off only kidding !!!

[jimkemp 526]

On 9/4/2019 at 4:23 PM, WVHillbilly520H said:

What about a "conduit" bender? ...https://bisedwardsironworkers.com/td90-1-125x3-edwards-tube-die-1-1-8-x-3-90.html?gclid=Cj0KCQjwwb3rBRDrARIsALR3XeaclLNGb9d_1CmPlfqLYTqzK6PQ7fIB3ydSY0Nd7nojDBaNN4K5fssaAnUtEALw_wcB

The problem is that those benders are 1 1/8 x 3 , the "3" stands for 3" radius , that's way to big

[jimkemp 526]

On 8/31/2019 at 2:47 PM, lynnmor said:

So you need this with a much smaller radius?  I didn't really expect formal prints, just a sketch that shows dimensions and mounting holes.  Perhaps you could trace around your smallest tooling and then show the reduced numbers.  A few photos might help.  I do think this will be a tough bend job with that small radius.  I have a tool & die shop and am pretty much retired, my interest in this project is only to help members and possibly get stainless mufflers.

 

I do have a spent muffler for a pattern if you need it.

The problem with making I die that small is the tube bender I have ( woodward fab ) wont except any smaller die , a whole tube bender would have to be made , a die , a follower die and a way to pull the die around to pull the tube through , the only way I see it happening is to buy weld elbows and piece the pipes together , only ones I can find 1 1/8 are stainless steel ,and there not cheap, stainless can be welded to mild steel to make the rest of the tube , but all the time it will take to do that plus build the muffler buy the flanges , I don't have one of these motors to build it on so now I would have to build a fixture off of another muffler , that all takes time that I wish I had but since I drive a tractor trailer and haul propane and winter is getting close , my time in the shop gets less and less , So if you can come up with a way to bend the tubing and make the tube part I would be interested in buying the tubes to build the rest of the muffler , 

 

And just so you know to build an all stainless muffler you would be in the $400 range , stainless aint cheap

[Pullstart 63,201]

Could you post a picture of what you’re trying to duplicate Jim?  Maybe somebody here has an idea to build them?  @Achto...

[lynnmor 7,384]

2 minutes ago, pullstart said:

Could you post a picture of what you’re trying to duplicate Jim?  Maybe somebody here has an idea to build them?  @Achto...

Post #31, and others, have a photo.  I have been doing a bit of research to come up with a way to reliably bend those pipes in stainless steel.  Those sharp bends are smaller than any engineering standard would recommend.  I could make tooling, but if the tubing will not accept the radius, it is all for nothing.  I'm not saying it is impossible, just a challenge to develop tooling and a procedure.

[Pullstart 63,201]

10 hours ago, lynnmor said:

Post #31, and others, have a photo.  I have been doing a bit of research to come up with a way to reliably bend those pipes in stainless steel.  Those sharp bends are smaller than any engineering standard would recommend.  I could make tooling, but if the tubing will not accept the radius, it is all for nothing.  I'm not saying it is impossible, just a challenge to develop tooling and a procedure.

 

Gotcha, they are the header pipes?  Rookie comment from someone with no Onans in the shed...

[jimkemp 526]

On 9/5/2019 at 8:29 PM, lynnmor said:

Post #31, and others, have a photo.  I have been doing a bit of research to come up with a way to reliably bend those pipes in stainless steel.  Those sharp bends are smaller than any engineering standard would recommend.  I could make tooling, but if the tubing will not accept the radius, it is all for nothing.  I'm not saying it is impossible, just a challenge to develop tooling and a procedure.

The tubing will accept the radius , its just the tooling ( die ) has to hold the shape , they are made in the factory with a rotory bender , where the die rotates and pulls the tubing into the die , the die is deep enough so the tube is more than 1/2 way in , in other words if you want to bend a piece of tube 1" od the die has to be at least 5/8" deep so the wall of the tube cant flex outward , todays benders the die are 1/2 the depth of the tube , 1/2" deep for 1" tube , it can be done , its just not cheap to do for someone like me with a small welding shop its way above what I could ever afford to buy