308 QV - Correct Radiator / Surge Tank Cap | Page 2 | FerrariChat

308 QV - Correct Radiator / Surge Tank Cap

Discussion in '308/328' started by robo330, Feb 6, 2017.

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  1. Labman

    Labman F1 Rookie

    Jun 25, 2010
    3,774
    Long Island, NY
    Full Name:
    Steve
    Just replaced my new OEM style (squarish) cap with a Stant 10331 with red lever. I let the car warm up and when it got to temperature, coolant started spewing out of the overflow tube going to bottom of car. Does this mean I have a bad Stant? Scared the heck out of me so I put the OEM style back on. 1983 308 QV.
     
  2. GordonC

    GordonC F1 Rookie
    Owner Rossa Subscribed

    Aug 28, 2005
    4,119
    Calgary, AB, Canada
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    Gordon
    That depends on what the fluid level in the tank was when you switched caps. If you topped up the fluid and the level was within an inch or two of the top, then some overflow would be expected.
     
  3. robo330

    robo330 Formula Junior

    Apr 15, 2014
    608
    Michigan USA
    Full Name:
    Karl Robertson
    I believe seeing somewhere on a previous post that the coolant level should be between 45mm and 50mm down from the top of the Filler Neck when the engine is stopped.
     
  4. Labman

    Labman F1 Rookie

    Jun 25, 2010
    3,774
    Long Island, NY
    Full Name:
    Steve


    This could be. Major was done last year and I think it was filled close to the top. So what causes it to come out with the Stant? Pressure difference?


    Sent from my iPhone using Tapatalk
     
  5. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
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    Brian Crall
    Water expands when hot and is not compressible. The cooling system needs X amount of air for expansion space so it spit out water until that space was achieved.

    Also many times the Italian caps rubber seal will expand not allowing pressure relief. I have tested some that would peg the gauge on my tester, your may have been one of those.

    Put the other cap back on.
     
  6. Labman

    Labman F1 Rookie

    Jun 25, 2010
    3,774
    Long Island, NY
    Full Name:
    Steve


    Interesting and understood. I most certainly will. Thanks Brian :)


    Sent from my iPhone using Tapatalk
     
  7. tinterow

    tinterow Formula 3

    Nov 1, 2014
    1,339
    Houston, Tx
    Full Name:
    Chaya Tinterow
    IMHO...I switched recently and the 1.1 is the best...for me ;)
     
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  8. bpu699

    bpu699 F1 World Champ
    Owner Silver Subscribed

    Dec 9, 2003
    16,210
    wisconsin/chicago
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    bo
    Anyone know of a generic radiator cap that works/fits?
     
  9. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
    3,079
    SanFrancisco BayArea
    Full Name:
    1983 US 308 GTS QV
    Stant 10230
     
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  10. bpu699

    bpu699 F1 World Champ
    Owner Silver Subscribed

    Dec 9, 2003
    16,210
    wisconsin/chicago
    Full Name:
    bo
    #35 bpu699, Jul 5, 2020
    Last edited: Jul 5, 2020
    ‘thanks!

    That’s the 1.1 or 16psi one, correct?

    I have a 0.9 right now, is there a part number for that’s psi also?

    Will try the one you suggest...

    Does a higher psi increase risk of water pump seal/failures? This is for a testarossa, if that matters...
     
  11. Dr Tommy Cosgrove

    Dr Tommy Cosgrove Three Time F1 World Champ
    Owner Rossa Subscribed

    May 4, 2001
    35,282
    Birmingham, AL
    Full Name:
    Tommy
    No.
     
  12. Brian A

    Brian A F1 Rookie

    Dec 21, 2012
    3,079
    SanFrancisco BayArea
    Full Name:
    1983 US 308 GTS QV
    Apparently Ferrari issued a Service Bulletin for 308s where they increased the recommended system pressure to 1.1 bar.

    The first owner of my car used 0.9 bar caps for the 30 years he owned it. When I bought it, I decided to increase the pressure with a 1.1 bar cap figuring if a measly 0.2 bar pressure increase blew my hoses, I wanted to know about it. I've been running 1.1 bar ever since.

    I can't comment on TRs; ain't never even got a ride in one.
     
  13. Dr Tommy Cosgrove

    Dr Tommy Cosgrove Three Time F1 World Champ
    Owner Rossa Subscribed

    May 4, 2001
    35,282
    Birmingham, AL
    Full Name:
    Tommy
    I have been using a 1.1 cap since Sept 1997.

    If they were going to cause a problem, im sure I would seen it by now.
     
  14. miketuason

    miketuason F1 World Champ
    Owner Silver Subscribed

    Feb 24, 2006
    15,517
    Cerritos, CA.
    Full Name:
    Mike
    Although my .09 bar cap still works great, I went ahead and switched to 1.1bar a few months ago and it works great.
     

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