308 Oil Pressure Regulator | FerrariChat
Buy

308 Oil Pressure Regulator

Discussion in '308/328' started by GNJ, Jan 13, 2008.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. GNJ

    GNJ Rookie

    Aug 20, 2005
    5
    #1 GNJ, Jan 13, 2008
    Last edited by a moderator: Sep 7, 2017
    I am getting oil spray in the engine bay of my 1977 308GT4 and am in the process of eliminating possible causes. I have dismantled the Oil Pressure Regulator (pictures attached).
    1. Is there a piece missing? (the exploded view on the parts list appears to show an additional part).
    2. The piston shows scoring on two sides and is also chamfered in two places. Is this correct?
    I would appreciate any comments on this.

    I think this is a great website with superb contributions - very informative and makes owning a Ferrari even more of a pleasure!
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  2. mk e

    mk e F1 World Champ

    Oct 31, 2003
    13,742
    The twilight zone
    Full Name:
    Help me get this thing finished! https://gofund.me/39def36c
    #2 mk e, Jan 13, 2008
    It's really a pressure relief valve that limits maximum pressure to something like 100 psi. I don’t recall ever seeing flats before and I’m quite certain they don’t belong there….there is no way to know how they will be oriented in the final assembly. The scoring indicate the piston in moving on a regular basis.

    I think your car has some kind of blockage in the oil system and has had for some time. I think the flats were added in an attempt to low the excessive oil pressure the blockage is causing and when you replace the piston your pressure will jump right to 100 psi…..then you’ve see where the leak is :)

    (but you'll still need to find the blockage and correct it)
     
  3. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    7,022
    Groton, MA
    Full Name:
    Verell Boaen
    #3 Verell, Jan 13, 2008
    That 'extra' piece is an optional shim that increases the oil pressure required to open the bypass.

    The shim compresses the spring, thus increasing the oil pressure needed to move the piston back against the spring.

    The shim is just a flat steel disc.

    Once you get the blockage fixed & replace the piston, you may need one.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Jan 13, 2008
    Where? (Is there some thread I missed with prior discussion?)
     
  5. GNJ

    GNJ Rookie

    Aug 20, 2005
    5
    #5 GNJ, Jan 13, 2008
    No, you haven't missed any of the thread. The oil leak appears as a mist on the inside of the engine hood. The back of the car also develops a yellow tinge (the car is white) which is due to an oil film. So it is not oil burning off or passing out through the exhaust. I have cleaned the engine (paraffin spray) and there are no obvious places that is it coming from BUT there are signs of weepage at the interface between the distributor casing and the cam cover. I have replaced the 'O' ring seal on the distributor shaft recently, but the oil mist could be due to oil forcing its way past the 'O' ring. Is that likely? And if so, does that mean that I have got excessive pressure in the cam casing?
     

Share This Page