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SNAFU; a high performance 318is build, Turbo M42 ➞ Turbo M20

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    By the look of it the front will be way easier than the rear. Rear was bad enough that after I replaced one on my own I had a shop do the other one. Front looks straightforward as long as the race doesn't separate, but even if it does it seems a 3-jaw puller should be all I need.
    @turbovarg
    '91 318is, M20B25, T3/T04E 60 trim (15psi), megasquirt, coilovers, Z3 rack, cold AC
    [b u i l d]
    [Car of the month: April 2018]

    0c8b7c9527af628a346878feb14bf757

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      Originally posted by varg View Post
      Ah this weekend. It started as a fixing a simple thing, a blown out turbo gasket caused by fasteners that won't stay put:



      Then this happened:



      And then this:



      All because this stud showed up in a search for "m8x40 exhaust stud":



      I didn't bother to look up 45H steel, which is a set screw specification, and according to ISO898-5 "The use of set screws of hardness class 33H and 45H under tensile stress (axial or bending) is not recommended." For a project in school, or in my future job as an engineer I'd definitely have looked into this 45H spec before ordering, since it would be my job to double check something like that, but since this was "just hobby stuff" I didn't and here I am. I spent a few hours trying to weld a nut to the stud and back it out last night and failed, I need to get some nuts that aren't contaminated beyond what a wire wheel can fix. Now I'm working on stuff for school and don't know if I'll have time to fix this before the school week starts. I'm so glad I couldn't replace the other studs when I got my new hardware in months ago because I couldn't remove them without taking the header off, they may have all broken because I was torquing them down pretty tight to compensate for a warped header flange. The stud didn't break when I torqued it down, it stretched, and when I went to remove the nut that's when it failed.
      those are the ones i was going to use. 45H isnt a bad material the specs dont call out a yield strength only hardness. it never dawned on me that they are meant as a long grub screw... they are prone to hydrogen embrittlement though from memory. what did you end up using? you can get stainless but those are not strong and need to probably antiseize the crap out of them . i might just end up using stock ones lol
      89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

      new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

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        I ended up salvaging and using the old stock studs. I soaked the ones with seized nuts in penetrating oil then clamped them double nutted in my vice and eventually got all of the seized nuts off and used new nuts. Any studs that come out with the nut in the future will just get replaced with OE studs, since it seems appropriately rated studs with a hex for driving them in are not available in the size I need.
        @turbovarg
        '91 318is, M20B25, T3/T04E 60 trim (15psi), megasquirt, coilovers, Z3 rack, cold AC
        [b u i l d]
        [Car of the month: April 2018]

        0c8b7c9527af628a346878feb14bf757

        Comment

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