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308 Trans & Diff Cooling & Oil Req'ts

Discussion in 'Technical Q&A' started by pma1010, Mar 31, 2004.

  1. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    2,559
    Chicago
    Full Name:
    Philip
    Early 308s had no cooling excepting the metal fining. Later ones had some supplementary ductwork. Mine gets really hot at the track. As I posted in the venting discussion, when the vent was blocked once, I bled it for 20 - 30 seconds a week later. Scared me. On cars usually spending more time at the track (or at least designed that way), like the F40, Ferrari added a diff/trans cooler. Anyone looked at something like this or have an other thoughts on how to address the issue?

    Also, Ali Haas or one of the oil guys, what's the temp at which the trans oil starts to break down and how close to that is the trans likely to get after 3 or 4 hours hard use on a hot (90 degree ambient) track day?
    Philip
     
  2. AEHaas

    AEHaas Formula 3

    May 9, 2003
    1,350
    Osprey, Florida
    Full Name:
    Ali E. Haas
    Gear oils tend to have flash points around 200 - 220C. The heat should not hurt them. However, Ferrari transmissions have "yellow" metals as copper or brass that are corroded by some gear lubes at higher temperature. Redline and Shell are safe. Agip is probably safe. Mobil is definitely not safe.

    You may want to take a temperature reading just as you come off the track with one of those infrared meters. Make sure you use one that has a emissivity setting. It must be set to aluminum to give a proper reading. Otherwise you can be off by a factor of 2 or 3. My Maranello transmission runs around 125 - 130 F with around town driving. I consider this cold. The manual states that the cooling circuit does not even come on until 185F.

    The ambient temperature wether 70 or 90F just does not make much difference.

    aehaas
     
  3. 4re gt4

    4re gt4 Formula 3

    Apr 23, 2002
    2,279
    Roseburg, OR
    Full Name:
    Hans E. Hansen
    It's a bit up in the air as to whether 308 series gearboxes have any 'yellow' metal in them. Many who have overhauled their boxes insist that there isn't any. The syncros are magnetic and appear similar to sintered iron. However, someone suggested that there *may* be some bronze bushings.
     

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