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holding cam in place without gears

Discussion in 'Boxers/TR/M' started by plip, Sep 4, 2019.

  1. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
    Full Name:
    Gianni Olivieri
    Hi

    whilst doing the major on my TR, want to replace cam seals and O rings all around.

    Haven't done it before on this engine so my question is, once the gears are removed, have camshaft tendency to rotate form their set positions ? If so any hint how to keep them in place ?

    Incidentally, one of OR 'swelled up'.

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    and ya...the tensioner bearings were definitely overdue....

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    Many tks

    Gianni
     
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  3. ronc52

    ronc52 Karting

    Aug 25, 2010
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    Ron
    A old timer told me to use a business card under 2 of the camshaft bearing caps front and rear on each cam and that locks them down
     
  4. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
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    Gianni Olivieri
    tks so the do tend to rotate when gears are off....
     
  5. xplodee

    xplodee Formula 3
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    Jan 3, 2017
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    Tim
    What about just doing the timing after? Seems like this would be the most responsible way and is also part of a major, technically.
     
  6. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
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    Gianni Olivieri
    have not expressed myself properly. Currently the cams are blocked by their gears

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    Do need to replace the seals and the o rings on all cams therefore need to remove the gears. My question is: once the gears are removed, and therefore the cams are not blocked in position anymore, do they have the tendency to rotate from their set position under the pressure of the valve springs? As said, never done it on this engine before....
     
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  8. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    romano schwabel
    I did the belts several times on BB and TR`s and the cams never moved when I put away the gears. it is a 6 cylinder.
    on a 4 cylindre it sometimes happen that the cams turn without gears a little
     
  9. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
    Full Name:
    Gianni Olivieri
    Vielen Dank Joe.

    That's precisely why have asked. It happened to me on 8 cylinders engine as well.
     
  10. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,879
    #8 vincenzo, Sep 4, 2019
    Last edited: Sep 4, 2019
    The cams will likely not move on their own. That said however - not checking the timing is just asking for trouble. IMHO. -

    NEVER remove the cam gears without checking timing.
    NEVER replace ‘just’ the belts unless you have previously confirmed the timing. Even then, a recheck is HIGHLY recommended.

    More info:
    https://www.ferrarichat.com/forum/threads/83958-major-2016-cam-timing.513496/

    To be more clear - if you remove the cam gears you WILL have introduced an error in timing. Look at the slop in the system after the bolt is removed.

     
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  11. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
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    Gianni Olivieri
    Tks. Timing has been duly checked b4 locking the cams and removing the belt. all marks align as well as the dial gauge set to zero on cil 1 on compression stroke. Noted the slop in the system after bolt is removed.
     
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  13. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,879
    Timing by ‘marks’ on the cam will only get you close enough to keep from crashing valves as you time the engine.

    They are only there for initial assembly prior to timing.
     
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  14. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    romano schwabel
    always adjust the belt timing with a degree wheel
     
  15. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,879
    Compare this pic with the slop introduced into the system when the cam gear bolt is loosened.

    Here is a sample showing the marks with the cam nearly 4 degrees off:

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  16. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,879
    PS: 4 degrees off and it will not pass a smog check in California. Likely no state that requires a gas analysis.
     
  17. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
    Full Name:
    Gianni Olivieri
    Tks Guys. Am waiting for the seals and OR to arrive. Will tackle the timing once reassembly on the way. Noted on emissiom check vs cam timing. As a matter of fact am due smog test every 2 years here. Car passed last July with cams set as they are now. Incidentally noted the cams timing datas on wokshop manual are not matching with datas on the user manual. Will have to get tools for setting valve at 0.5 for timing. Meantime studying Vincenzo's post in dets.
     
  18. pshoejberg

    pshoejberg Formula 3
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    Dec 22, 2007
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    Never unlock the cams with no belts on! As mentioned earlier, a piece off thick paper below one of the cam bearing caps will solve your problem.

    Best
    Peter
     
  19. plip

    plip Karting

    Aug 25, 2003
    246
    Switzerland
    Full Name:
    Gianni Olivieri
    Tks Peter. Will do.
     

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