Mahle Piston Failure

Discussion in 'House of Power Racing' started by Trojan, Jun 16, 2008.

  1. Trojan

    Trojan Trillions Bro! Right on!

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    Welp! I really did it this time. Cylinder 1 piston ring glands busted. No signs of detonation. All the rings were in 1 piece still on the piston. I swapped the camshaft/Heads last week for Columbus and while doing a comp ck noticed cyl 1 was down 100psi from 200. We could see the comp ring end gap and the piston/cylinder looked fine. I though we had a blown head gasket. Once the Cam/Heads were on we did another comp ck hoping it was the gasket, Well it wasnt. I really think this is a manufacturing flaw in the piston, Anyhow Im gonna replace all the Mahle's with JE's as soon as I can get a set. Im really pssst we had to pull the motor, SO anyways just a heads up on a MAhle Piston Failure.

    Heres a couple pics off my iphone.

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  2. 1bad4dr

    1bad4dr Mr. Meany

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    OUCH.

    Chris that sucks, but I guess finding it early is better than complete failure...
     
  3. Trojan

    Trojan Trillions Bro! Right on!

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    yeah Ron, she's fixable. Thats twice for my busting a piston and still running on 7 cylinders no worries. I ordered some JE Pistons but there 3 weeks out. :cry:
     
  4. 1bad4dr

    1bad4dr Mr. Meany

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    Yea, JE is the better way to go... IMO

    sorry for the trouble Chris. lol At least I know what you are going through. ;)
     
  5. Inferal

    Inferal Full Access Member

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    Sorry to hear that Chris I was looking forward to seeing you

    Man how come always number 1
     
  6. REZ-RACER

    REZ-RACER New Member

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    Sorry to hear this chris
    hope you get her up and running again soon!!!
     
  7. Trojan

    Trojan Trillions Bro! Right on!

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    I was looking forward to seeing you to! Why number 1 you ask? Beats me but this sumbitch runs on 7 all day long.

    As quick as we can get parts we'll be up again.
     
  8. 1fastsedan

    1fastsedan Destroyer of Warranties

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    That sucks to see Chris. I'm glad to hear the damage wasn't too bad and you'll be up and running again soon. Do you have a front cross-over on your fuel rails?
     
  9. Trojan

    Trojan Trillions Bro! Right on!

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    No front crossover. I know the cyl 1 issues but we dont think this was the issue.
     
  10. Stretch

    Stretch Silver Supporting Members

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    That sucks big time Brudda! At least like Ronald said, only damaged that instead of something worse. Are you replacing with the same type?
     
  11. Trojan

    Trojan Trillions Bro! Right on!

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    Im not taking a chance with the Mahles again, Im looking into JE, Diamond's. I will pull the other 7 pistons out tomorrow and see if theres any issues with them.
     
  12. 8yourM5

    8yourM5 Full Access Member

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    Funny I have 2 of these that need to be replaced.I am going to be changing my cam at the same time. I am guessing it would be smart to maybe change my pistons as well for F/I since I will have it apart right?
     
  13. Quick

    Quick Mgmt. - I can't help you

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    Maybe if they're right on the edge, just a tiny bit leaner in #1 so a tiny bit hotter and a tiny bit more power and a tiny bit more stress and... Maybe?
     
  14. Trojan

    Trojan Trillions Bro! Right on!

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    John,

    Are they Mahles? Did they break were mine broke? Break it down for me!
     
  15. HoP Racing

    HoP Racing Mad Scientist

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    Fueling was not the issue here. I personally think Mahle itself is a great Piston manufacturer, I think that this piston design in particular was poorly engineered. Tomorrow I'm taking the busted piston with the other good one and having them reverse engineer the piston. At present JE does not make a piston for this stroke, so I'm having them engineer a box style piston for this application. Sucks but leave it to Trojan to find the weakness. If Trojan can't break it it's good to go. Didn't I see 12's at fontana on 7 1/2 cylinders :erm: ?
     
  16. PPPAndy

    PPPAndy New Member

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    Thats strange. We have used allot of Mahle pistons and I havent seen this happen yet. I think Johns issue is with the rings, not the piston itself, but he can answer that better than myself. I actually have the RDP blower on a 10.3 compression engine with the Mahle piston without any issues so far.
     
  17. Hemi31

    Hemi31 [email protected]

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    I am actually going to agree with Andy here.Looks like a ring issue.
     
  18. Trojan

    Trojan Trillions Bro! Right on!

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    Johns issues were not the rings, All rings are fine and not broken or rolled, The ring gland on my piston and johns gave way, John had 3 of them do the excat same thing. So now what?
     
  19. Hemi31

    Hemi31 [email protected]

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    Ring's don't need to be broken or rolled.If the end gap is to tight for the expansion properties of the alloy the ring is made from under high temps then it would be easy to do that damage.
     
  20. Trojan

    Trojan Trillions Bro! Right on!

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    Erik I appreciate your input. And after meeting with JE its making sense what your saying.

    Ok update,

    Went down to JE today and spoke with the engineer over there. We brought them the broken piston and a good one from another cylinder. They seemed extremely knowledgeable and basically did a piston autopsy for us.
    He told us the gland broke downward. He said the XX32 aluminum the Mahle is made of is more brittle then the XXXX aluminum they use. I forget the 2 types. He said the he would never go that thin with that type of aluminum.
    He also said the car detonated but not from gas. Not from a tune. From Oil.
    He said it looked like the oil was getting on top of the piston, Like it was'nt draing back thru the holes. He said detonation like this will not cause dimpling or spawling on the piston. But he was 100% sure. He was not bashing on the Mahle design but said he didn't like quit a few things about it including the oil drain holes, He said he'd like to see 4 instead of 2. Not sure if anyone remembers this about my build but the oil rings were funky, And we had to trim them.
    So there you have it. They said they would make me a set. And upgraded design based on what he saw with the current design.
    Heres all the pics. Like I said the first thing out of his mouth was the gland broke downward. And it was from Detonation from a oil problem in that cylinder. He believes the oil issue was a piston/ring issue as well.
    Most of this is way beyond me. Have at it guys!

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    Cyl 7 Piston for comparison.
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