12.7 reman capital engine compression coming out of intake manifold

Discussion in 'Questions From New Drivers' started by monte ott, Sep 16, 2021.

  1. monte ott

    monte ott Bobtail Member

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    we installed a capital reman. engine set rack an injectors an jake brakes went to start no compression . we found air blowing out intake an poping out exaust manifold. my mechanic said all timing marks looked lined up before putting front cover on it. please any help would be heipful. thanks in advance.
     
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  3. Dockbumper

    Dockbumper Road Train Member

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    LOOKED lined up.......or WERE lined up. Big difference between those two words in that context.
     
  4. lovesthedrive

    lovesthedrive Is here to help

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    Valves arent seating. Valve clearance is too tight or valve rocker isnt releasing
     
  5. jamespmack

    jamespmack Road Train Member

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    What tune up procedure did you use, timing circle or valve overlap.

    Timing circle procedure has been discontinued since the late 90's due to this exact reason.
     
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  6. monte ott

    monte ott Bobtail Member

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    we used valve overlap procedure
     
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  7. jamespmack

    jamespmack Road Train Member

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    Good. Do you know for certain you used proper clearances? Next thing is to verify timing per manual.
     
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  8. monte ott

    monte ott Bobtail Member

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    yes to proper procedure and checked twice. Intake valves set at .008 & exhaust valves set at .026. Capital engine reman set the timing of all the gears. we just installed cover over it. Somebody told me that if Capital Engine put a 11.1 bull gear on, that timing marks would be different and causing issues. Do you know if this is correct?
     
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  9. jamespmack

    jamespmack Road Train Member

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    Thats a good question? I can't answer that. Only put one bull gear in a 11.1 about 17 years ago. Im out on the road and my books are at home.
     
  10. lovesthedrive

    lovesthedrive Is here to help

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    Other question is did you make sure all valve springs had about the same amount of force. If the spring is weak it too will cause for leaking valves.

    I presume the valves were lapped?
     
  11. jamespmack

    jamespmack Road Train Member

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    I'm almost certain 11.1 and 12.7 use the same bull gear.

    Crank shafts, pistons, liners are different.
     
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