2856361 ‘68 383 & 440 single exhaust resonator detail.

Engine, Transmission & Driveline

  1. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    As I was looking for exhaust options on my ‘68 Polara 383 I decided to go back to the stock single exhaust. As I was researching part numbers I discovered that the rear tailpipe was actually a resonator. This intrigued me. So I did some searching and found a NOS tailpipe with resonator PN 2856361 and ordered it. I could have just as easily put on a regular tailpipe but after I saw this I had to have it.
    It is 2-1/4” out of the muffler and bent to clear the axle before going into a 2” inlet on the resonator. Inside the resonator it continues to pass through at 2”, but the first half has holes drilled allowing some of the exhaust pressure into the outer chamber which is about 2-3/4” in diameter. Exit is 2” as well.
    image.jpg image.jpg image.jpg
     
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  2. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    I have to nerd out a little more and measure for posterity.
    If anyone has an old resonator that is no longer serviceable and would be willing to cut a cross section of the resonator so we can all see inside, that would be cool.

    The resonator itself is 35-1/2” long from inlet to tip of scallop.
    image.jpg

    The resonator body is 23-1/2” long (the 2-3/4 outer body) before it necks down on either side.
    image.jpg

    It also has a little drainage hole at the end/ bottom of it to drain condensation.
    image.jpg

    Then the subject of all exhaust threads. What is the tailpipe outlet supposed to look like?

    The 318 single exhaust has a little upturn and then comes back down, but the 383 and 440 single exhaust the pipe comes straight out with a scallop.
    The scallop starts at a 30 degree angle and then transitions to a 15 degree angle about midway. Diagonal length is about 3-1/2” from top tip to bottom opening. The top of the tip has about a 15 degree downturn about the last 1-1/2” on top.
    image.jpg
     
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  3. FURYGT

    FURYGT Senior Member

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    Interesting to note the baloney cut on the end of the tail pipe.
     
  4. Dodgedon

    Dodgedon New Member

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    Is that the tail pipe i found? If so that was some fast shipping!
    So the exit is 2" and not 2 1/4. What were you thinking about the new rear hanger? He had that band clamp in 2" also.
     
  5. odcics2

    odcics2 Active Member

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    Mufflers bring the entire exhaust note down.
    A resonator is tuned for a certain RPM range.
    May have fiberglass in it, or just be chambered inside.

    Nice find!
     
  6. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    Yes the one on eBay. It came from GA priority post. The ends were capped and it was just shrink wrapped really good. The ebay tracking had it with Fedex with the 16th as the delivery. Showed up on the door step tonight. I think I ordered it Monday.
    Let me see what 68plymouth383 has. He says he might have a good used original hanger.
    For the NORS hangers you found I am pretty sure I would have to turn the bottom of that hanger around for it to fit right. There is only 4-1/2” of pipe that the hanger can go on. I hate to spend that kind of money and still have to rebuild it. But if I find that is my only choice... I will do what I can. I will need a 2” clamp for sure though.

    Thanks for your sleuthing.
     
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  7. Dodgedon

    Dodgedon New Member

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    The new hangers look nice but i do agree that the hook seems like it should have been pointing forward. I wonder if they are all like that?
     
  8. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    They look spot on except for that. If they were something that he is currently producing it would be pretty easy to make a few the right direction.
     
  9. Dodgedon

    Dodgedon New Member

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    It would be easy to flip it around and re-rivet. It kinda looks like a brake lining rivet on heavy trucks.
     
  10. CBODY67

    CBODY67 Senior Member

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    This is interesting! Usually, the OEM rear resonator is a separate item which is clamped to the over-the-axle pipe out of the muffler. Which generates the "resonator eliminator" pipe to replace it, when it perforates. That's the way our '66 Newport 383 2bbl was, the '72 Newport Royal 400 2bbl, and the later single exhaust cars were. From my experiences, the resonator eliminator pipe made things a little louder and better sounding, bur not enough to notice inside the car.

    In looking in the '65 Chrysler parts book via www.jholst.net, it seems there are TWO listings for that rear pipe. The one as pictured is listed in one group as "Muffler" and the straight pipe is listed as "Pipe". Same picture, two different pipes, different parts groups. In the "Muffler" group, it's termed "rear muffler" for CPD non-wagon cars.

    The dual exhaust cars usually didn't have the rear resonator, except Imperial convertibles prior to the '67 model year.

    The "slice" on the end is more for ground clearance of the pipe's end when going into a steeper driveway approach . . . or to not drag the ground when being loaded onto a tow-bed truck, should the need arise. A full circle end would dig into the ground, loading and unloading . . . not good.

    Just some thoughts,
    CBODY67
     
    Last edited: Jan 13, 2019
  11. ImpJay

    ImpJay The different young FCBO Gold Member

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    Did 67-68 Imperials have resonators with the optional 360hp 440?
     
  12. odcics2

    odcics2 Active Member

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  13. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    Yes For ‘68 (I have not paid too much attention to other years) the resonator application is single exhaust only.
    In the ‘68 parts book and service diagram it is one p/n for both the resonator and axle bend pipe. There is no separate listing for a resonator, or just the over axle tail pipe for the 383 & 440 single exhaust. The wagons (all engines)and 318 did not use a resonator. Just a different bent tail pipe.
     
  14. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    I can check the parts book later today. I have those pages pretty well dog eared by now.
     
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  15. commando1

    commando1 Mr. Normal FCBO Gold Member

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    This looks correct:

    s-l1600.jpg

    Personally, I don't ever recall this style. Looks aftermarket. I could be wrong.
    It also looks to have some Stainless in in the steel.
    image-jpg.jpg
     
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  16. FURYGT

    FURYGT Senior Member

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    Look at the photos again. There is a Chrysler part number sticker at front mounting area - photos 1 & 2.
     
  17. commando1

    commando1 Mr. Normal FCBO Gold Member

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    Missed that. :thankyou:
     
  18. CBODY67

    CBODY67 Senior Member

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    I'll agree on both counts. I don't ever remember seeing the lower item on a car, but it obviously existed as the '65 CPD parts book illustration and parts listings validated something of that sort for the 1965 models, so it could have extended to later models, too.

    Walker Exhaust, and others, listed the "rear pipe" as a two piece situation. The over-the-axle pipe joined by a resonator w/rear tip or a "resonator eliminator" pipe to complete the OEM one-piece item. The resonator was usually where the "wear" issues were, so it was cut off and either a new resonator or resonator eliminator pipe installed. All with the factory "turn down" configuration.

    From about '66 on, I was around the local C-P dealer many times when we'd get our '66 Newport serviced or attended to. I was always looking around at the new cars and others in the shop. We werew all friends and we enjoyed some interesting conversations on the new stuff, back then. Plus the service station for oil changes and minor stuff. I believe that if I'd seen that "one-piece enlarged resonator" tail pipe, I would have remembered it. Be that as it may. More "unknown" things discovered in the parts book!

    CBODY67
     
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  19. odcics2

    odcics2 Active Member

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    This thread is exhausting me...

    :rofl:
     
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  20. HWYCRZR

    HWYCRZR Senior Member FCBO Gold Member

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    ‘68 parts manual. The picture above looks correct in the pm for a single exhaust 440 Dodge, Chrysler 300 and New Yorker.
    Here some manual pics that back up the one I received. There is an error in the illustration calling it 11-09-3. You go to that section it doesn’t list my application, but is in 11-01-1. Pics below.
    image.jpg image.jpg image.jpg image.jpg

    Bottom yellow highlighter image.jpg