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How to build a Muffler for a Briggs Vanguard


maxwood

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Hello, I have been repowering my sovereign with a briggs vanguard 16 HP engine and needed a muffler so I decided to build one!!here is a write up: This muffler will fit a Briggs Vanguard V-twin **Cutting, grinding & fitting of parts is required. Materials needed: 1-4” muffler pipe, 13-1/2” long 2-pieces of 1” conduit (EMT), 6” long 1-piece of 1-1/4 inch conduit (EMT), 8-1/2” long 1-piece of 1-1/4 inch conduit (EMT) 5” long 1-18ga sheet metal, needed for the 4 inch circular end caps (2) & interior baffles (2) 2-1” washers, 3/16” thick Component construction: Muffler Shell *Drill two 1-1/8” holes, 11” on center, into the 4” pipe. (The exhaust ports on the vanguard are 11” apart) Exhaust Manifold Pipes *Perforate the first 3” of each 6” conduit piece to be fitted inside the muffler, by drilling 3/16” holes. *Cap the muffler end of each pipe with a large fender washer. Exhaust Manifold Gaskets *Trace an exhaust gasket on the 1”x3/16” washers and drill the appropriate holes and trim to shape. One will be a left hand and one will be a right hand. *Weld these to the perforated 6” long tubes. Center Resonation Chamber *Drill 30-40, 3/16” holes into the 8-1/2” piece of conduit, to perforate. *Cut 4 circular Baffle Plates. 2 must fit inside the 4” exhaust pipe, while 2 must be 4”OD. (Set both 4”OD pieces aside) *Drill a 1-1/4” hole in the center of the remaining 2 Baffle Plates.* Weld the 2 drilled circular Baffle Plates onto the now perforated 8-1/2” piece of conduit, near each end. Assembly: *Insert assembled Resonation Chamber into Muffler Shell. *Tack-weld Resonation Chamber in place. *Identify orientation of engine exhaust ports (These are not the same distance from the muffler body because of the cylinders being offset) *Insert perforated ends of Exhaust Manifold Pipes into the 1-1/8” openings in the Muffler Shell (taking into account the exhaust port orientation) *Fit Exhaust Manifold Pipes for alignment with exhaust port flange bolts, then weld into place. *Identify 5” Exit Pipe location suitable for your tractor. *Drill 1-1/8” hole, insert Exit Pipe and weld into place. * Weld remaining 4” inch circles to each end of Muffler Shell. *Paint as desired with suitable high heat paint. *Bolt assembled muffler to the exhaust manifold and mow the lawn before you get ‘the look’ for playing out in the garage/shop/barn too long. Mine is on the bottom, offset to the right in the center chamber area, so that it will exit out front & below the frame of my Sovereign. I was surprised how quiet it was when all done.








Thank's to talntdmrgreen for collaboration on the written explanation Ken in Mi
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Hello, Thank's for the compliments . Before I started this project I looked at how mufflers were designed ,and the theory of sound dispersal. The exhaust flows into the end compartments and then into the center chamber bouncing around losing sound energy as it goes through the muffler. Some tractor mufflers don't have a center chamber and work well. Thank's Ken in Mi
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Since we've found a now-experienced muffler fabricator, I'd like to suggest another experiment... You used to be able to get (not sure now) what was called "quiet mufflers" for old air-cooled VW headers, that used very similar components to those above and no fiberglass packing (or any packing, for that matter). They had an inlet on one end and the outlet on the other. They connected one of those perforated tubes to the inlet, and it went full length to the other end, where that end of the muffler blocked the end of the inlet tube. The outlet was simply the opposite... a perforated tube that was blocked on the inlet end by the end of the muffler. The exhaust gas had to go out of the holes on the inlet tube, richochet around inside the cannister, and then out through the holes in the outlet tube. A very simple design, with no packing to deteriorate, and the quietest muffler ever made for them, with good exhaust flow... I'd like to see someone make a stack muffler for the old cast-iron one-lungers like that, just to see how much you could quieten one down without robbing power...
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Ken, whadaya think? I can donate the one-lunger and you can donate your time, tools, workspace, materials, expertise, patience and document the process? I will also watch 8D
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Hello, I am up for a "MUFFLER BUILD" The design sounds like the motorcycle mufflers,on My 1965 Honda Superhawk 305cc that had an insert that could be removed for a louder sound . The insert was a perforated pipe that would slide in the rear of the Muffler about 6-8 inches and bolt in place . I always took them out! should be a fun project! Ken In Mi
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One thing I forgot to mention that might make it more difficult, or even impossible. The muffler itself was slightly oval shaped, to allow space for the two tubes that ran down its full length inside. Don't know if you could somehow squeeze the straight length of large pipe you're using for an a muffler body into an oval, or even if it is necessary... The one-lunger Briggs exhaust is 1" ID, but I think the Kohlers were 1-1/4 or 1-1/8... not sure.
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I'd like something a bit different on an FDT...something similar to the look of the exhaust on the Lombardi's tht runs horizontal...the wheels are turning. ;)
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