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Rear Exhaust Hangers

Discussion in 'LS-427' started by crzyfst, Jun 28, 2015.

  1. crzyfst

    crzyfst Member

    Anyone have a proven/long lasting setup? I finally had one break after only 3K miles or so. See attached picture as I'm not sure how many different variations might be out there. My build is around 4-5 years old. The nut seems to just be glued into this rubber mount and it finally tore around it and popped out.

    I saw a really old post where someone put an eye bolt into the side of the frame. Just wondering what other solutions might be.

    Thanks

    Attached files 4784-2075.jpg (138.8 KB)
     
  2. undy

    undy Member

    I had the same problem. I finally went to solid steel engine mounts so I could solid bolt the side pipes with no flex. Three years later and I have never had any side pipe problems since.
     
  3. crzyfst

    crzyfst Member

    hmm pretty sure my engine mounts are solid. My whole car/chassis or engine must twist a lot though as the spot where my exhaust exit the car you can see rub mark where it hits the body. I have actually cut the body to give more room around there so not sure if it still hits. I can't seem to stick my head out there when I mash the gas :D.

    So if my engine is solid mount, then I should be ok using solid mount for my exhaust?

    Thanks
     
  4. TexasDoc

    TexasDoc Member

    If you have the rubber mounts that go between the bracket that attaches to the motor and the frame, you do not have solid motor mounts. The metal bracket is solid, but the 3 inch square rubber mounts that those brackets set on allow the motor to flex when torque is applied.

    There is another thread discussing this topic. There are a few good options.
    http://www.ultimateclassiccars.com/lscbb3/viewtopic.php?f=3&t=1490&sid=d6546a903d327cc1b0222eb9132b3553

    If you use a solid motor mount, you can use a solid rear mount. You probably also want to make the transmission mount solid too. All or none. Do not use a solid exhaust mounts if you use rubber motor mounts.
     
  5. Barnsnake

    Barnsnake Member

    Even with solid engine mounts it would be a good idea to allow for thermal expansion. Between fully hot and dead cold that pipe will change length by a measurable amount.

    The broken mount pictured appears to be designed for a load directed straight down from the nut end toward the mounting plate (compression). It probably wasn't designed to handle tension or lateral shear.

    Jim
     
  6. 427GTO

    427GTO New Member

    I have polyurethane engine and transmission mounts, I was going to use the rubber isolators on the exhaust to absorb the vibration from the exhaust and also keep any frame vibration from transferring to the exhaust and breaking the weld on the exhaust tabs, is this correct?
     
  7. wyocobra

    wyocobra Member

    I run factory type rubber motor mounts under my big block chevy, built my own headers to Lone Star's side pipes and just bolted a piece of angle iron to the side of the main frame with a couple of 5/16 self tappers. A couple of 5/16 bolts with nylock nuts go thru shock absorber rubbers on top and under the frame bracket sandwiched under the flat plate welded to the sidepipe. Leave the bolts slightly loose to allow the rubber to flex a little.
    13 years and 7000miles later, they still look and act just like the day I bolted them up.
    Most of the time, simple is still the best!
    This pic is looking straight down.

    Attached files 4785-7.jpg (32.6 KB)
     

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