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Thread: athena HG with OEM head bolts

  1. #1
    Join Date
    Nov 2013
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    Germany
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    '96 328i w/ M50B25 turbo

    athena HG with OEM head bolts

    hey there. please dont ask why, but is there anyone who has tested athena cut ring head gasket with OEM Head screws? im talking about a M50NV (hp goal 400-ish on stockblock) but experiences with other engines (also non BMW) are interesting, too.

    greetings

  2. #2
    Join Date
    Aug 2011
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    philadelphia PA
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    1993 325is
    With cut ring gaskets it doesn't require as much clamping force to seal as other HG types. So for 400 you will probably be just fine with stock bolts.

  3. #3
    Join Date
    Apr 2006
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    Minnesota eh?
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    86 325es
    I don't think it would be a problem. A stock head gasket will live at that power level too.


    86 325es, 2.8L m50, S472sxe, MS3pro Ultimate, e85, solid rear axle, 4 link, spool, TH400 trans, Protorque converter, 28x10.5w slicks, zip ties
    Best = 9.43 @ 149.15 mph, 1.30 60 foot 28 psi boost

  4. #4
    Join Date
    Nov 2013
    Location
    Germany
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    My Cars
    '96 328i w/ M50B25 turbo
    now that i'Ve got some more time to write: background is that i have built a forged engine over the last time, what has taken all the money i saved. (i'm still at college. is that what its called in the USA? lol)
    engine worked pretty fine on idle, we already had some working tunes for these engines and put them together for a save mapping and then tried it on the street. engine ran for about 20km and startet rattling. we looked after it and thought its coming from vanos, which was in uknown condition and not rebuilt. so we decided to take a video and then drive back to the garage. well, 10secs after the video ends, my rod crushed my block. piston is compeltely torn apart, block has two holes, head is also f*ckd.

    we checked cam timing and saw that intake to exhaust timing was right, but the crank was nowhere at TDC. so we think that the chain may have hopped. but we dont know for sure. i think we'll never know.

    when we took off the old head, the athena seemed to be in pretty good condition, the rings could be taken out of the head easily and the gasket looks fine, except one small part on the front at the chain case.
    my friend still has a M50B25NV, that needs to be checked, so it would be helpful to take off the head anyway, and then we can reuse the athena with gasket spray when we put it back together, everything else will stay stock.

    other option would be ordinary 12.9 aftermarket screws as head bolts. but i've heard that the stock head bolts are 12.9 too? can anybody confirm this?

  5. #5
    Join Date
    Apr 2006
    Location
    Minnesota eh?
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    My Cars
    86 325es
    I think the stock ones are 10.9 but not certain. Either way I think stock will be fine.


    86 325es, 2.8L m50, S472sxe, MS3pro Ultimate, e85, solid rear axle, 4 link, spool, TH400 trans, Protorque converter, 28x10.5w slicks, zip ties
    Best = 9.43 @ 149.15 mph, 1.30 60 foot 28 psi boost

  6. #6
    Join Date
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    1993 325is
    Your power goal is very conservative. Stock bolts will be fine no need to try anything else.

  7. #7
    Join Date
    Nov 2013
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    '96 328i w/ M50B25 turbo
    Thanks im trying to get these 12.9 oem bolts, some guy i know had these in his hands. Maybe he still knows where he got them from. I wouldnt be mad if it were 450+ hp but i think that knock will limit the power.

  8. #8
    Join Date
    Sep 2017
    Location
    Netherlands
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    e36 328i turbo
    Can you post a link/OEM number, I am looking into Head studs/bolts for my M52. only option I have found is the raceware M54 studs. which is a pretty expensive option.

  9. #9
    Join Date
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    '96 328i w/ M50B25 turbo
    I only know that these were from elring. But you can buy ordinary 12.9 screws everywhere, theyre just a bit more expensive than stock ones and i personally dont like the fact that theyre only available as allen screws.

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