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Discussion in 'PSI Superchargers Tech Questions' started by bandit496, Jul 12, 2010.

  1. bandit496

    bandit496 Member

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    Torched a piston, but I have a set mate to replace it with. The replacement was balanced when rotating assembly was done. The build has 4 tractor pull passes on the bearings. Should I go with a new bearing on the replacement or use the bearing on the rod (it looks okay). BBC with 14-71 SSI. Just looking for what you guys think is right.
    JW
     
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  2. SoDak

    SoDak Active Member

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    Jason
    Amazingly I have torched pistons without hurting the bearing either. It seems to be a BBC thing. I have been in the position where replacement wasn't an option and ran it again without problems. If you have another I'd change it.
    Is this on your mini?
    What heads do you run?
     
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  3. bandit496

    bandit496 Member

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    Yep on the old motor. #2 cylinder as always. Added 10 points of fuel before second run, but it obviously wasn't enough. Brodix BB2X heads with a new perfectly flat surface. That cylinder will never see a 72 nozzle jet or grey plug end again!!!!! It is in--waiting on refurbished head to put it all back together (but may have to go with backup set of heads that flow better and really mess the fuel setup jabberwocky). Event this weekend. JW
     
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  4. SoDak

    SoDak Active Member

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    Do those have inside head bolts?
    Did it torch the head where the combustion chamber meets the flat quench area?
    You richened it .010 and it still torched, I'd be checking hat nozzles to see if they are plugged.
     
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  5. bandit496

    bandit496 Member

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    Yes on the extra head bolts. And yes for the first time on the "melt" at the quench area. Never had that happen before. It pushed out the front. Somehow we are evidently getting some preigniton or something between the quench areas. We had just checked all of the nozzles at the hat and the ports. The fuel gets filtered. Have you ever seen a maggot in the nozzle from a wasp laying an egg in the vent from one weekend to the next??? I have. Wasn't my motor, thank goodness. Just some crazy things--who would think something like that could happen?? Anyhow, I am going to relieve that combustion chamber to get a little less compression. The motor is due for a major at the end of the season if it makes it. I just know now that a second pass on a hot motor will take more than 10 points. JW
     
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  6. SoDak

    SoDak Active Member

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    I like your wasp story:eek:
    Last Aug. we had some hat nozzles plug and torched #2 also, sounds extremely similiar to what yours did. Sand roll that edge (chamber to quench) into a radius and it can handle quit a bit more leaness (is that a word?)
    Once that alum. starts to erode its all down hill from there.

    Any chance the main accidently recieved a .010" larger pill on the hot run?
     
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  7. bandit496

    bandit496 Member

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    Yeah, the wasp story is true. How the heck can you stop a wasp from getting in the trailer or shop? That maggot was certainly embalmed! We are relieving that quench area. No on the pill--from 75 to 65. All the lines and nozzles will be double checked today on assembly. JW
     
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  8. visionary

    visionary New Member

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    this may sound stupid but check the intake gasket seal on that #2 intake, always use the thick gaskets on the BB Chevy.

    i had this happen a few times when i used to run the chevy and it was always the # 2 runner.
     
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