Timing O-Rings? | FerrariChat

Timing O-Rings?

Discussion in '365 GT4 2+2/400/412' started by Jagbuff, Dec 25, 2016.

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  1. Jagbuff

    Jagbuff Formula 3

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    Franck
    #1 Jagbuff, Dec 25, 2016
    I am falling into the typical "while there" trap after redoing the full body restoration of my 400iA. Now the body is done I am waiting for the glass (front and rear windshield :( ) my focus has shifted to the engine bay for detailing and repainting of the cam covers amongst several (many) other things.

    "While There" going to replace all the hoses, all the belts (...some Italian is laughing somewhere), clamps, plugs, wires, distributor, fluids etc...the usual "easy" stuff.

    "While There" I am going to check the valve lash as well as replace the timing chain since the car is running out of adjustment. Honestly, I dreaded the prospect of a worn down tensioner that would require an engine out. Santa came early and all the chain control parts look in great shape (photos will follow when I do a sum up of the resto). So I plan to thread the chain through and check the cam timing and adjust if needed.

    That said, when I pulled the covers the O-rings between the cam cover and the chain cover seem to need attention. Someone must have worked on the engine before as they are split....

    Question: What is the trick to replace them without removing the front timing cover? I have heard that splitting them is OK but what is the best way to push the new ones through?

    ...BTW Merry Christmas, Happy Hanukkah, and winter solstice everyone!
     
  2. Motob

    Motob Formula 3
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    Brian Brown
    #2 Motob, Dec 25, 2016
    While I don't recommend doing this, it can be done. You cannot push a new o-ring through the groove, it will just bunch up. You need to pull it through, stretching it and making it thinner. I cut the o-ring, , cut tapers on one end, punch a small hole in it and tie safety wire through the hole. I then lube the o-ring with three-bond gasket sealer and route the safety wire into the hole and around the groove. I then pull the o-ring around the groove using the safety wire. The o-ring always ends up being too long, so I then cut off the end that I tapered and tied the safety wire to so it is the correct diameter.
     
  3. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #3 Rifledriver, Dec 26, 2016
    When you say split, are they cut at the top so they are no longer a continuous O ring? If so that was done at the factory. If they are cracking or splitting at the parting line of the head and valve cover, that is another matter. I have just cut the o ring flush with the head and cut an upper half of a new o ring so it will fit in the groove of the chain cover from gasket surface to gasket surface and installed with a dab of a good silicone sealant at each end many times very successfully.
     
  4. Jagbuff

    Jagbuff Formula 3

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    #4 Jagbuff, Dec 26, 2016
    Thanks for the responses. Brian, they are cut at the top so I presumed (erroneously) that someone had come up with alternate way to install. Unfortunately only 3 are "intact', the 4th broke nearly flush with the head so I'll follow your alternate method.
     
  5. GT Jones

    GT Jones Formula Junior

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    #5 GT Jones, Dec 26, 2016
    Frenchie, i wonder if you can extend the slot on the alternator bracket and finds way to make belt installation easier?
     
  6. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #6 Rifledriver, Dec 26, 2016
    Why? They go on quite easily if the correct sequence is followed.
     
  7. Jagbuff

    Jagbuff Formula 3

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    #7 Jagbuff, Dec 27, 2016
    Replacing all the belts so no biggie since there is plenty of space out front especially since the radiator out for service...Honestly the 400 is the "friendliest" F-car to work on that I have owned - at least so far:)
     
  8. mike32

    mike32 F1 Veteran

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    #8 mike32, Dec 27, 2016
    In industry they normally put a drop of superglue on the o ring ends to join them.
     
  9. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #9 Rifledriver, Dec 27, 2016
    They do not need to be held together, they need the gap filled to prevent oil leakage and superglue will not do that.
     
  10. TTR

    TTR F1 Veteran
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    #10 TTR, Dec 27, 2016
    + 1.
    Also, once cured, most "superglues" tend become too hard and brittle for flexible, especially dynamic, applications.
     
  11. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #11 Rifledriver, Dec 27, 2016
    That's true but some superglues are not. There are some sold in the hobby sector that allow for flexibility especially when attaching rubber. A client of mine gave me some that used an aerosol accelerator that I have used to glue the 90 degree corners back together on door seals. Not perfect but works pretty well. Check with your local radio control hobby emporium.

    Still, not an issue with the o rings in question.
     

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