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430 Scuderia broken exhaust manifold head studs

Discussion in '360/430' started by dwe8922, May 24, 2019.

  1. dwe8922

    dwe8922 Formula Junior
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    Has anyone else had this happen? I have two broken studs; one on each side. The broke off flush with the cylinder head. I originally thought it was a bad header, but once I got into it, discovered they were broken. My headers look fine, and I've not read of much problem of failure with Scuderia's compared to the 360's. Just curious to see if anyone else has had this.
     
  2. f355spider

    f355spider F1 World Champ
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    Common problem for Scuderia and 16M according to my dealer. What is happening is the flanges on the exhaust manifold warp, causing the studs to stretch and break. Even before the studs break, you will often have the telltale sign of an exhaust leak at the flange from a ticking noise at cold start. It usually goes away as the car warms up. Under warranty they would simply replace the exhaust manifolds with new, but found the problem often recurred, necessitating another replacement. Their current solution is have the exhaust manifold flange ground flat, replace all the studs (since the unbroken ones may be stretched or weakened), use new gaskets, and reinstall. According to them, they have not had a car return for the same problem, so the flanges don't appear to continue to warp.

    Most dealers continue to replace exhaust manifolds that leak at the flange with new ones. That is only a temporary fix at best.
     
  3. dwe8922

    dwe8922 Formula Junior
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    I had a friend who was Alex Job's crew chief help me back out the two broken off studs (right after your reply came through; thank you), and he thought the stud design was flawed. He agreed with having the machine shop check and adjust the header flange if necessary, but recommended buying better studs, and thought ARP would have something that would work. Has anyone used an alternate part, or know if the current part has been updated over mine? I think mine are original.

    Also, mine had those exact symptoms. I was expecting it to be a cracked header, not broken studs on both sides.
     

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  4. f355spider

    f355spider F1 World Champ
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    The flaw is in the exhaust manifold flange.
     
  5. mike32

    mike32 Formula 3

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    It might be worth thinking about undercutting the last thread where it meets the plain section, that will reduce the stress point, you could just drop it in a lathe and use a parting blade with a rounded blade to make a U section
     
  6. windsock

    windsock Formula Junior
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    Just have the machine shop surface the header. Throw in new factory hardware, nuts, gaskets you will not have another failure. Don't over think this I've done dozens.
     
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  7. f355spider

    f355spider F1 World Champ
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    From the guy that did mine ;)
     
  8. dwe8922

    dwe8922 Formula Junior
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    Thanks for the history on what you've seen. I've bought all new gaskets, studs, and nuts. My car has about 24k on it.

    So, once it's warped initially, and resurfaced, it won't warp any further?
     
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  9. f355spider

    f355spider F1 World Champ
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    #9 f355spider, May 26, 2019
    Last edited: May 26, 2019
    See post #2 and #6 again, that is what Windsock told me, and FoS. I'm not sure how many different ways this can be restated.

    "According to them, they have not had a car return for the same problem, so the flanges don't appear to continue to warp."

    "...you will not have another failure. "
     
  10. windsock

    windsock Formula Junior
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    correct.
     
  11. LightGuy

    LightGuy Two Time F1 World Champ
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    #11 LightGuy, May 27, 2019
    Last edited: May 27, 2019
    Is this an engine out procedure if the studs are broken ?

    Would it be wise to do this as preventive maintenance for a car with some miles ?

    I'm considering a higher mileage Scud as my next Ferrari.
     
  12. f355spider

    f355spider F1 World Champ
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    #12 f355spider, May 27, 2019
    Last edited: May 27, 2019
    Engine doesn't come out. You can't do the job as preventive maintenance...it requires the flange to warp first and is then ground flat. There is nothing to prevent this from happening. Wait until it happens, then fix it if it does.
     
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  13. dwe8922

    dwe8922 Formula Junior
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    Thanks for the clarification. I'll report back what the machine shop finds.
     
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  14. Russell996

    Russell996 Formula 3
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    Presumably changing to aftermarket headers would be preventative in a number of ways.
     
  15. windsock

    windsock Formula Junior
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    I did one set of aftermarket headers that a customer supplied. Worst nightmare I ever got suckered into. I should have gone with my first answer which was no but I let a longtime customer convince me to try. We had manifolds off three times in order to get them to fit right and then because of the lack of heat shielding it promptly melted and ruined the parking brake cables with in 500 miles. Customer sold the car.
     
  16. dwe8922

    dwe8922 Formula Junior
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    I put a set of Fabspeed headers on my old 360. They fit pretty well. I had them coated, but they still generated more heat than stock.

    I've only heard good things about tubi exhausts, and they are shielded. Just expensive. I looked into getting a pair when I thought my headers were going bad.

    It seems scuderia headers have been pretty reliable compared to the 360 ones. Have you seen this?
     
  17. RedTaxi

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    ^^430 headers are the ones that fail. Not so much the 360. Scud and challenge headers are are just 430 headers without the pre-cat so I can't see any flange warpage specific to the scud because the flange is the same flange as the 430. But hey maybe they warp too. Scud headers last better than the 430 because of the way the exhaust is supported further downstream.
     
  18. f355spider

    f355spider F1 World Champ
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    But alas, the 430 Scuderia and 16M exhaust manifold flanges do warp...a lot. I know a few other Scuderia owners that experienced the same problem...and saw invoices for repairs while shopping for a car. Could be a bad batch of metal used in production...who knows? But it is what it is. Never heard of a oem F430 exhaust manifold flange warping.

    I also know two 360 owners that had oem exhaust manifolds fail, I forgot in what manner, but not unheard of.
     
  19. Sky Hye

    Sky Hye Formula Junior

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    This ticking you mention... I recently noticed it after removing my S-Line exhaust. It goes away after a bit. I thought it may be low oil but that wasn’t the case. How would I inspect for this? It worries me now.


    Sent from my iPhone using Tapatalk
     
  20. brookliner7

    brookliner7 Karting

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    Curious, how did he back out the studs?
     
  21. windsock

    windsock Formula Junior
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    Scuderia and 16m headers are not 430 headers. They have air injection ports and rails in them which makes them fit very differently and also get a great deal more heat as they use the air injection to create the after burn in the header rather then in the pre cat. This creates a very rapid increase in temperature on a cold header within the first 2 min and causes the warp and failure of the manifold studs.
     
  22. RedTaxi

    RedTaxi Formula 3

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    I was aware of the air injection difference but thought that was only in effect for a very short time on cold start to bring the manifolds up to normal temp quicker. But I can see how heating something quicker could cause warping. I guess my challenge headers are the best of both worlds. No air injection and no pre cat. :D
     
  23. Sky Hye

    Sky Hye Formula Junior

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    Thank you windsock and 355. Just to clarify, would refacing scud headers also be a fix to the root cause?


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  24. f355spider

    f355spider F1 World Champ
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    I does not correct the cause, it does seem to prevent a recurrence of warping and exhaust leak, which is the source of the ticking noise.
     
  25. dwe8922

    dwe8922 Formula Junior
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    He punched the center of the stud, drilled it out enought to insert an ez out, and turned it by hand. I soaked it w/ penetrant ahead of time, and we used some map gas
     
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