348 Valve seating and clearances | FerrariChat

348 Valve seating and clearances

Discussion in '348/355' started by MaterMech, Jun 29, 2007.

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  1. MaterMech

    MaterMech Formula Junior

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    Los Gatos CA
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    Mark Johnson
    Well after the valve job there are a few valves that are out of spec +/- a couple of thousansths of an inch. I let the machine shop butt grind the valves so they are very close to spec. I want to let the valves seat properly before I make any adjustment. Intuition and experience tells me that it shoud be ok to run for a while like this before shimming. What do you guys think?
     
    MaterMech, Jun 29, 2007
    #1
  2. ernie

    ernie Two Time F1 World Champ Lifetime Rossa Owner

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    The Bad Guy
    I say shim them on the loose side of the specs. That way you leave some room for them to tighten up.
     
    ernie, Jun 29, 2007
    #2
  3. gothspeed

    gothspeed F1 World Champ

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    +1 the valves will settle slightly into their seats and heat will expand the valve stem length. So err on the looser side ;)
     
    gothspeed, Jun 29, 2007
    #3
  4. No Doubt

    No Doubt Seven Time F1 World Champ

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    I did not know that. Thanks Goth and Ernie!
     
    No Doubt, Jun 29, 2007
    #4

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