Cobra Crank and Rods Question.

Discussion in '96-04 - 4V Specific' started by vnmsgt, Jun 30, 2014.

  1. vnmsgt

    vnmsgt Member

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    I got a 98 Cobra motor with a spun bearing. I wanted to know is the Cobra GT Cranks the same? I have a block with good crank from a 96 GT also I was wondering if can be used? Also What about the rods, can they be swapped from GT to Cobra? Attached is a pic of the journal of the Cobra crank. Looks worse then it feels. Was wondering if I could get away with some light sanding and new bearing. Motor is stock and wont have any mods done to it. If not, whats the cost for turning a crank nowadays?

    [​IMG]
     
  2. SVTstang96

    SVTstang96 Well-Known Member

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    Gt cranks are not the same as the cobras. The gt will have a 6 bolt, non forged steel crank. This is a 8 bolt forged steel crank. That being said rods also probably are a different weight and will throw balance off. If i were you bring it to a machine shop where they can machine it and get you new bearings for probably $200. I was able to buy a 99 gt redone crank and bearings for $275 from a machine shop.
     
  3. D3VST8R96GT

    D3VST8R96GT Well-Known Member

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    The cobra(forged) cranks also have counter weights in the center and the GT (cast) cranks do not. The older blocks will need some machine work to have a cobra crank drop in. (Just had another thread about gt iron blocks vs cobra iron blocks)

    Well depending on how bad it is. My machine shop does it for $100 but Idk if that's the friend+cash price. If it does get turned I'm sure you know you will need oversized bearings.

    I would buy some boss rods and new pistons... get it rebalanced and the motor would be strong, budget friendly and will last.
     
  4. vnmsgt

    vnmsgt Member

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    The GT rods i do have here look slightly different so I wasnt sure.
     
  5. vnmsgt

    vnmsgt Member

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    I just found a friend with 8 stock Cobra rods I am buying for $20 so I should be ok.
     
  6. vnmsgt

    vnmsgt Member

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    I just hate having to remove the head to swap out the rod and piston! Motor is clean and didnt want the hassle. Was hoping the rod was ok and not blued and that the bearing was just a little bad so I can get away with just replacing the bearing.
     
  7. D3VST8R96GT

    D3VST8R96GT Well-Known Member

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    The rods will all be powder metal and on the weak end. Since they are from another motor plan on the rebalance and new rod bolts/main bolts. :)
     
  8. SVTstang96

    SVTstang96 Well-Known Member

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    Also that crank will need to be at minimum polished at a machine shop. leaving it like that will wear out a new bearing very fast. Then you will be in the same position but with a worse crankshaft in no time at all.
     
  9. vnmsgt

    vnmsgt Member

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    Thanks for the info guys.
     
  10. vnmsgt

    vnmsgt Member

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    May call a machine shop to see what they charge to fix crank.
     
  11. vnmsgt

    vnmsgt Member

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    I just got another 98 Cobra and it has a knock in it too. Now I have 3 4v's with knocks and 1 good. lol
     
  12. MustangChris

    MustangChris Legend Retired Staff SN95 Supporter

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    welcome to my life. LOL


    anyways, getting a crank re-polished here in Denver by a name-brand shop with a solid reputation runs about $300.00 for all parts and labor (new bearings.)
     
  13. vnmsgt

    vnmsgt Member

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    Finally got the rods from my friend. Cleaned out the garage to make some room to work on stuff but in a dilemma. Take this motor a apart to get it done at least so its sitting and ready or finish getting 91 GT suspension back on the car. 32v motor and trans are still bolted to the kmember I need to use to put in the car and at another house so have to get it over here, take up more room with a 3rd 32v sitting in the garage somewhere and at least get the car to roll. I have too many damn projects.