308 Crank case/ Head vening Issues | FerrariChat

308 Crank case/ Head vening Issues

Discussion in '308/328' started by tomoshea, May 2, 2011.

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  1. tomoshea

    tomoshea Formula Junior

    Dec 29, 2003
    541
    Ireland
    Full Name:
    Tom O'Shea
  2. Brian Harper

    Brian Harper F1 Rookie
    Owner Silver Subscribed

    Feb 17, 2006
    4,078
    San Jose area
    Full Name:
    Brian Harper
    I think the flow path is normal. Blow by vents through the heads - you want to vent from a high spot to expel as little oil as possible and also remove some of the water vapor as well that likes to condense up high in the engine. If you block off the vents the pressure from blow by builds up in the crankcase and forces oil up the return line.

    Is your real concern how much liquid oil is coming out after the seperator?
     
  3. tomoshea

    tomoshea Formula Junior

    Dec 29, 2003
    541
    Ireland
    Full Name:
    Tom O'Shea
    Hi Brian,

    my concern is whether the blow by vapour is normal.

    Previoulsy before rebuild I didn't have any and it was a fairly worn normal compression engine working at between 140 and 155 psi per cylinder.

    Cylinder pressure is now noth of 210 in each cylinder and with the JE pistons there is one less seal ring in the pistons 2 + oil scraper vs 3 + oil scraper ring with the Borgos.

    I have changed oil for the bedding in process to mineral oil 20 -50, not sure if this could be contributing factor? I changed the oil after about 700 miles of run in period. Was filled with old school mineral oil for rings/ preventing cylinder glazing.

    i am not consuming oil and have no nasty black/ blue/ white smoke from the exhaust on acceleration under load or when static.

    In all honesty my primary concern is whether there is something not quite right with the rebuild that was completed?

    Interested in perspectives, planning to do a pressure test next weekend, just to confirm nothing signifncat has changed since tested at about 500 miles in.
     

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