Well guys, here's how I custom built my own muffler. I'll be honest when I say that if you're using brand new stuff to start with like I have it's probably cheaper to buy a tractor muffler from your favorite store that sells them but if you have limited space and or just want to make your own then read on!
What I've done here can be applied to all sizes of round, off the shelf mufflers. The tricky part is the cylindrical "tube", you either need to find one that's the perfect size or make your own.
Anyways, here we go!
Here's the long since discontinued and No Longer Available Briggs and Stratton muffler that inspired me.
I started with a pair of these "pancake" mufflers...
...and a 22ga piece of sheetmetal (18"x12").
I used a piece of Bristol board that I wrapped around the outside of the muffler, to the outside of the seam at the largest point I could find to determine the outside circumference and I added 1/16" to account for the fact that the sheetmetal is thicker than the Bristol board, I figured worse come to worse I could trim it but in my case it worked out to be perfect!
Here's the trickiest part... rolling the sheetmetal into a tube. Myself, after getting frustrated talking to several fabrication shops about rolling it for me I gave up, broke down and spent $200 on a "slip roll" that can roll sheetmetal up to 22ga as small as 1" (they claim) and it worked well!
Once it was rolled I used a large hose clamp to hold it while I tack welded it...
...then fully welded the seams (please don't mind the crappy looking weld, it turned out to be the crappy wire I had tried out)...
... and ground the weld down.
For my project I cut the tube down to the length I wanted, you do what's good for you!
For a little extra flow I drilled the 1/8" holes out to 3/16".
Where we go from here is to put the perforated (outside) ends of the mufflers in the tube then weld it up!
Then clean it up really well and paint it! I used what was left of this can of high heat Rustoleum.
Then speed dry it with a heater!
Then get it on the tractor and take it for a good run to cure that paint and you're done!
There's so many possibilities to change the sound/volume if you want to experiment by adding a baffle(s) or muffler packing inside the chamber, just make sure you've only tack welded the mufflers in the tube until you're happy with it! I've found that as it is still gives a good tractor sounding noise while taking the edge off, had I not drilled out the holes (or drilled them smaller) I'm sure it would've been a touch quieter but overall I'm really happy with it!
I hope you enjoyed this and that it helps some of you out!
I've got some of them mufflers laying around. I use them quite often to rig duel exhaust on twin engines. They have a good tone, kinda simliar to glass packs.
I've got some thinwall EMT electrical conduit that might be the correct size for the body. The muffler on my Case 448 is getting weak.
Brianator, Nevadablue and TechnoChicken like this post
I'm actually not sure @JJF3RD because I've been tweaking and tuning the new carburetor pretty much every time I run it! Lol. I would doubt I would've needed to in my case though. If someone were to go from stock to a strait pipe or a much better flowing exhaust/intake I'm sure some tuning (enriching) would be required.
So you know, to tag someone and have a notification sent to them so they know hit the little @ symbol you see in the top right corner of their post.
Wow that looks like a great design you've come up with there nice job! Let us know the results
You should start a thread and do a little write up showing the process so others will see it when looking around, your design is different than anything else I've seen and I'm sure will have it's own unique ton AND it looks durable as heck! Lol
LOL, I probably should have documented more steps during the process. Lots of time spent looking at specs and listening to audio of the "howdzit's & what fer's" of various muffler designs while running dimension conversions in my head. In as much as these engines are just plain LOUD to begin with, I did want to try to quell the often obnoxious tone down a bit and as primitive as this is, it did (kept it low profile to boot). Got the delta idea from the Flowmaster line and as usual, have only the scrap stock here to work with. Hence, my inquiry as to the carb tuning . . . a point about exhaust mods which kept repeating (prevents engine from running hot??).
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Age : 45 Join date : 2019-07-02 Points : 4545 Posts : 2385 Location : Ontario, Canada
Can't say I've ever heard of exhaust mods preventing an engine from running hot before nor have I experienced it, what's the theory behind it do you know? The only thing that comes to mind is if you have a freerer flowing exhaust and haven't enriched the mixture (if required) the motor would run lean and lean equals heat so ya...? Lol.
The photos you've posted are enough if that's all you have, a little extra description between photos would help people "see" what you've done, I say go for it! It's really easy, in the exhaust section you would click the "new topic" button (upper left of page) and go to town!
So how does it sound? Just quieter or did it end up with a unique tone?
I wouldn't consider it unique, it just curbed a lot of that tinny "brapping" at higher rpm. The running leaner/hotter was the issue which I kept seeing come up. Now, here's the motive behind the madness for this endeavor. The "New Hooves" at the barn apparently have . . . ready for this one . . . "sensory issues". W.T.F. over!! They're fine with the quads and the Deere's running around all day long but fire Craftie up and they become like something possessed. Just what I need . . . more animals with "special needs" LOL!
Being this is a "shot in the dark" prototype and having listened to it, I would change what I now know to be a few design flaws. I do like how it tucks up nice underneath and if I opt for something similar for the GT project I'll make those changes and probably document the steps along the way. Don't want to tout anything I'm not really satisfied with myself . . .
I hear you man so was mine and I'd change a couple things myself if I end up building another although I am overall happy with it and it's definitely quieter than a single open "pancake" style muffler so it was still a win! Lol
I honestly don't care if we chatter in here because it's not a tractor build thread and the work is all done but I do encourage you to make your own thread for it so people can see what you've done! Only people that have come into this thread will see it and I think what you're doing is awesome and others will benefit from it too!
The roller would be a handy addition indeed. I have a brake that I DIY'd a few years ago but of course, has it's limitations. Can't do any new tools & toys right now though, some of these cherubs are rescues with various disabilities and recent vet bills have been brutal. An upside though, by necessity I've made a number of tools which I'd have otherwise just grabbed at H'Dumpo or online and none have broken yet LOL. Which wire did you mention re, the seams? Is it flux or are you using gas?
Looks to me like we're at about the same skill level with the thin stock. I've been using this Lincoln 140 with C25 on the A setting with .025/.030 and every "sinking" trick I've seen on Y'Tube tutorials but still have incineration issues LOL. Holes, smiles . . . LOBULAR masses (those are the worst).
I have a low end flux core wire feed, 80amp/110v with only Hi/Low and wire speed settings. A big part of my issue welding was that crappy Blue Demon (0.30) wire and the worn tip. New wire (Fourney - 0.35), new tip and I'm back to having less issues but still have power feed (to my house) complications but at least I'm getting cleaner welds now. Check out my most recent here.
The piece on the side was. 22 guage same as the muffler body and the bars were really thin galvanized (under 1/16") (yes I know the dangers/warnings of welding galvanized). I'm finding the thicker wire doesn't burn through as easily but the trick has always been the timing with thin metal... spot welding and holding it just long enough to burn it in but not through.
No, you're right I don't want to look at the price of that fabrication shop quality unit! Lol. There are decent ones on Amazon that are a little more than mine but still reasonably priced between $250 and $500
DIDN'T EVEN LOOK!! As was impressed upon us growing up . . . "If ya have to ask how much, you probably don't need it" LOLOL
I believe the saying is " If you have to ask, you probably can't afford it" But, yeah pretty much the same thing
This is an excellent idea for a muffler, I've almost burned a corn field down with the stock ones on the MTD's so redoing your exhaust is always a good idea, thanks.
LOL, the "popular" saying yes. Dad's typically was just "You don't need it" and left it at that. Limited time and materials were the deciding factors with this one. The original plan(s) called for something far more elaborate (don't most of them) however, kept getting $idetracked by other prioritie$. I may have to weld a mast to the frame right behind the engine to rig a sail as the price per gallon continues to jump . . .