Blown head gasket

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by Neil Morley, Mar 27, 2018.

  1. BEDNAR1320

    BEDNAR1320 Member

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    FWIW, I think you are at or past the boost limit of what 7/16" studs can reliably hold. What compression ratio is the engine? Most big HP/high boost guys with aluminum blocks torque from the outside in..............
     
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  2. Blownalky

    Blownalky Top Sportsman

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    Really, why would you do that?
     
    #22
  3. Neil Morley

    Neil Morley Member

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    Lowell at new century says he has customers of his are running 50+ lbs of boost with 7/16" studs and no issues and even though the block is drilled for 1/2" studs he assured me that for what I'm doing they were not necessary??? And I just helped tune a friends car with a 139mm F-3 pro charged BBC on alcohol with the same heads and studs and 50lbs boost and no issues? And same compression as mine 10.6
     
    #23
  4. BEDNAR1320

    BEDNAR1320 Member

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    I just think with 40# or more boost the 7/16" studs become questionable. Can it be done, evidently it can as with your examples. But I think if anything is off in the tune up it is more likely to become an issue with the smaller studs.
     
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  5. Neil Morley

    Neil Morley Member

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    I absolutely agree that the 1/2" head studs definitely would be stronger but whatever happened to bend a .250" wall wrist pin probably would have pushed out the gasket as well and had it not I may have not discovered the bent wrist pin until it was too late!
     
    #25
  6. Bob69

    Bob69 Member

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    Firstly there is no carbon in alcohol so it wont leave a "carbon trail".
    What type of spark plugs and heat range.
     
    #26
  7. BEDNAR1320

    BEDNAR1320 Member

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    You don't happen to use an on board primer system, do you?

    If so, maybe it's possible that the shut-off valve for that didn't close and you were sucking gas into the blower, just thinking out loud.....
     
    #27
  8. Mike Canter

    Mike Canter Top Dragster

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    I dont see where the torque of the head studs or size of the head studs is going to bend a wrist pin. That takes detonation or pre-ignition.
     
    #28
  9. BEDNAR1320

    BEDNAR1320 Member

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    I agree Mike, I guess I got a little off track with the head stud thing. I just think about 40# boost and those 7/16" studs being a potential issue. That being said, it has nothing to do with a bent wrist pin that's for sure.
     
    #29
  10. Neil Morley

    Neil Morley Member

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    I really appreciate everyone's educated opinion on trying to figure out exactly what occurred but in the past when I pushed out a head gasket on number 5 cylinder ( it did number 7 this time) both times under power, last time it not only Fire slotted the head gasket, the head, and block, but also pressurized the cooling system and blowing water all over and didn't bend a wrist pin, but this time even though it pushed the head gasket into the water jacket , wouldn't if it was detonation which would happen under power at least pressurized the cooling system or fire slot the gasket or something??? It didn't even push any water out till I did a leak down, and I'm not doubting any opinions, just making sure all the evidence is out there.
     
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  11. kosky racing

    kosky racing Comp Eliminator

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    Just asking -could that wrist pin been in since last go arround
     
    #31
  12. Neil Morley

    Neil Morley Member

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    No it was number 5 last time and number 7 this time
     
    #32
  13. Bjs344

    Bjs344 Member

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    A crossfire seems like the only plausible explanation. If it were me, I would probably chalk it up to laying on the chip and something went wrong with the ignition. Did you ever say why it laid on the chip?
     
    #33
  14. Neil Morley

    Neil Morley Member

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    I should have set the rev limiter higher, it was at 8100 and probably should have been 8400 or so
     
    #34

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