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Thread: 46-51 Chief exhaust question

  1. #1
    Join Date
    Nov 2008
    Posts
    265

    Default 46-51 Chief exhaust question

    I have a 1946 chief that I made the correct exhaust system for but it's too loud and makes riding unpleasant. I'm looking to use the 1948-51 Chief system just for riding IF i an find one that actually muffles the sound. Were Indians that loud back then? It's actually obnoxious how loud most of our bikes are now. And with the straight thru no back pressure design of the repros they backfire upon throttle release too often.
    Are any of the systems out there any quieter than others? Has anyone else found a way to lower the volume?
    I hate riding thru quiet areas now, thanks in advance.

  2. #2

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    Howdy Mr Beard,

    Depends on how determined you are and how stock you want it to appear, if so, here goes. Have your existing exhaust hot tanked to make it surgically clean. To index for later accurate aligned reattachment, flip it over and scribe a line where the rear of the muffler can meets welded seem of the bulkhead leading to the final tail pipe. Cut your exhausting muffler off at that can bulkhead’s existing seam/weld to give you access to the interior if the can. Measure the distance inside the can to the forward bulkhead where the inlet pipe enters and then the short distance within rear bulkhead to the final tail pipe outlet is attached. Take an old muffler from your parts pile and cut enough of the tail pipe aft of the can to go the length of your muffler can firmly joining the inlet spigot of the header pipe with the outlet of the tailpipe, approximately 13 to 13.5 inches on most modern repops. Lightly bevel both ends so they the insert firmly into the inlet and exhaust pipes.

    Now, make what looks like two large washers, these will support this pipe within your can, outer diameter an almost interference fit, inner on pipe almost the same. Locate and weld these two washers about an inch or two inboard of each end on the pipe so they do not foul the weld lines where your can mates the bulkheads and spigot firmly into the header and tailpipes.

    Go to Autozone/NAPA and purchase a muffler known baffled with high temp fiberglass, or a new ex HD you may have laying around, emphasis on new. As opposed to telling you what size holes to drill in this pipe I’d check any old HD muffler/resonators you might have laying around or the the car one you just cut open. The larger the holes drilled, the more you knock that high end exhaust crack off but at the same time expose more direct exhaust heat to the fiberglass shortening its life. Once drilled, wrap the pipe, stuff the works tightly in the can, weld the rear washer perimeter to the inside of the can and the reweld the rear bulkhead to the can.

    When doing mine 20 years ago Browns happily replated the whole works by plugging each end of the muffler on the assurance that if it did leak and foul the tank my pipe was perfectly clean and my glass new. Don’t know what you’ll find nowadays.

    Note, this setup reasonably preserves flow through by not having any internal plate baffle literally rerouting the exhaust gases so is technically a resonator, not a muffler. Therefore, it is not going to be overall quieter per se, rather it will knock that higher end exhaust crack off while the deeper bass remains, which the former is what I think you’re trying to suppress. If you want a hint of what this yields take and old towel, doubling it over a few times and strap it over the exhaust outlet. Good luck sir, a good winter project.....even in sunny Florida.

  3. #3

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    Used to repack my two stroke Toomey race bike mufflers with steel wool!

    Dave

  4. #4

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    Howdy Dave,

    Used to do that regularly with my Maico back in the day when a residential development rose next to a stretch of our dirt bike trail and a noise ordinance began to be enforced. You mention repack, steel wool is fine when accessible to be renewed, the problem is any condensation results in rust and in no time it blows out your pipe in a copper colored cloud. As one will be welding up this setup rendering it inaccessible and Bob lives in humid Florida that’s why I mentioned fiberglass.

  5. #5
    Join Date
    Nov 2008
    Posts
    265

    Default

    Thanks, but I'm looking for something with a little less work. I may just buy a 2 piece, 48-51 style and shove a baffle of some sort in the junction of the 2. And save my obnoxious 1 piece for the shows I never go to anymore.
    But in my own 40 years of riding and building these, they run a LOT better with some back pressure, as do all low RPM engines. Open exhaust is really only for high RPM Horsepower, not the low RPM torquers like ours.
    But were they this loud back then? That must have been awful, with virtually thousands of them driving around. I feel like an idiot on mine, like I'm trying to get people to look at me. Like the Sportster riders of the 70's, only mod was remove mufflers.

  6. #6
    Join Date
    Jul 2010
    Location
    Vermont
    Posts
    753

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    So Bob....take this beat up Starklite exhaust off my hands (shipping is your only cost) and see what you can do to make it quieter!

    I took one of my snowmobiles in trade once and fired it up in the warehouse so I could evaluate what I now owned. Well, a roasted peanut fragrance was overwhelming after warm up...and it got stronger and stronger. "What the heck?" So I pulled the muffler and shook/poured out a large quantity of peanuts...at least two cups worth! They actually deadend the sound, and smelled good doing it!
    Pisten Bulley is Harry Roberts in Vermont.

  7. #7
    Join Date
    Jan 2008
    Location
    S.E.N.Y. State American side of Hudson River
    Posts
    485

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    On my 13000 mile 48 with original exhaust in good condition it is LOUD. Maybe it bounces off the sidecar a bit but it is MUCH louder than any of my Pans or Shovel with stock exhausts.
    D. A. Bagin #3166 AKA Panheadzz 440 48chief W/sidecar 57fl 57flh 58fl 66m-50 68flh 70xlh

  8. #8
    Join Date
    Jan 2009
    Location
    East TN, north of Chattanooga
    Posts
    35

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    Back in the late 90's I got my exhaust from Rocky Halter and I would say the sound is perfect. My buddy's Indian has either an original or 60s era repop on it and I find it obnoxiously loud with popping on deceleration. Maybe Rocky still uses the same source

  9. #9

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    Howdy chaps,

    Popping on decel easily provoked by leaks at header inserts to cylinders and muffler or backing off the advance at speed. Have had more than one old timer reminiscing about fully retarding at speed in second to announce their glorious arrival at a gathering with what sounded like gunshots with the fuel charge essentially not lighting till it was part way out the exhaust port.

    On the other hand my 346 with one of those round bulkhead aftermarket mufflers from the 60’s now emits a dulcet tone filled with sludge and oily carbon after I ran it until the compression was so low it would no longer completely burn oil splashing around the cylinders, greasy sludge both dripping out of the header to muffler joint and some ocassionally spitting out the tail pipe. Carbon makes a good sound dampener.

  10. #10
    Join Date
    Nov 2008
    Posts
    265

    Default

    Peter, the load pop on decel is directly from lack of back pressure. I hate it, the only way to avoid it is raise the idle so the throttle shaft doesn't full close. Buthen you have to retard the crap out of it to get a decent idle or it's grind-em-up going into gear.
    I'm going to play with a 2 piece exhaust and I'll report back any success I have in restoring rideability and lowering obnoxious noise.

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