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Weber jet sizes

Discussion in 'Vintage (thru 365 GTC4)' started by Colin Angell, Sep 26, 2004.

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  1. Colin Angell

    Colin Angell Karting

    Jun 17, 2004
    117
    #1 Colin Angell, Sep 26, 2004
    I have a 365 GTC with tripple 40 DFI/7 carburettors, which need some attention. Does anyone know the original "standard" jet sizes? I know that mine have been played with over the years and I would rather go back to the right starting point before tackling any development.
     
  2. dm_n_stuff

    dm_n_stuff Four Time F1 World Champ
    Lifetime Rossa Owner

    Dec 10, 2003
    43,755
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    Dave M.
    #2 dm_n_stuff, Sep 26, 2004
  3. Peter

    Peter F1 Veteran
    Owner

    Dec 21, 2000
    6,440
    B.C., Canada
    #3 Peter, Sep 27, 2004
    According to "Ferrari Tuning Tips & Maintenance Techniques" by Gerald Roush and John Apen, they only list a close example for the "365 GT" with 40 DFI/5 carbs, whose specs are:

    Choke: 32mm
    Mains: 195
    Idles: 60
    Pump Jet: 60
    Aux. Venturi: 4.50
    Air Correctors: 200
    Needle Valve: 175
    Idle Air Corrector: 125
    Emulsion tubes: F2

    Float level is only specified as 6.50. Whether this means the travel, or the distance from the carb top, I don't know.

    Hope this helps...
     
  4. Colin Angell

    Colin Angell Karting

    Jun 17, 2004
    117
    #4 Colin Angell, Sep 28, 2004
    Thank you Peter.

    Unfortunately there were a few cars fitted with 40 DFI/7's and of course mine has to be one of them! I seem to draw a blank from all the places I have tried and everyone assumes I should have 40 DFI/5.

    Is there any clever weber expert out there who can help?
     
  5. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    #5 Ferrari_tech, Sep 28, 2004
    Colin,

    Am making some enquiries, could take some time though, I must confess that I didn't know of the 40DFI/7's on the 365.

    Are you based in the UK - your name seems to ring a bell ?
     
  6. Colin Angell

    Colin Angell Karting

    Jun 17, 2004
    117
    #6 Colin Angell, Sep 28, 2004
    Hi Malcolm,

    You have been giving me advice with my transaxle rebuild, which is why my name sounds familiar to you. I'm pleased to say the case is sealed up again and I should have it back in the car very shortly. Thanks for all your help and I hope you are able to dig out some information for my Webers'.

    Colin
     
  7. Kram

    Kram Formula Junior

    Jul 3, 2004
    867
    Park bench, Canada
    Full Name:
    Mark
    #7 Kram, Sep 29, 2004
    Colin,
    Good luck with the Webers - and here’s why. The standard jet size is a good starting point if you are using the same fuel blend that Ferrari did when the car was new. If your gas is different, such as being lead free or not being 101 octane, then you will need slightly different jets anyway. I’ve found this out the hard way, having run the same 250 GT for over twenty years in three different countries. Every time a government legislates a new emission law that alters the gasoline or I move to an area with a different blend it’s back to the box of jets to compensate for the new burn characteristics. I don’t have a 365 so I can’t help you directly, but when you do get the information it probably wont' be a plug and play solution.
    Put another way, looking at the present jets will probably be more help to you than knowing what the factory settings were when the car was new.
    Kram.
     
  8. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    #8 Ferrari_tech, Sep 29, 2004
    Colin,

    Thought so - Still no luck with the information, I'm relying on someone who is digging through the archives at what was Webber UK.
     
  9. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    #9 Ferrari_tech, Sep 29, 2004
    Colin,

    Not good news, Webber can't find any information on the 40 DFI/7's, they have info on the 2,5, and 6's but nothing on version 7.

    Italy has drawn a blank, not surprising as they ceased production some 20 years ago.

    I can't think of there being a major difference between 5 and 7 (although there must have been a reason for the change) and would recommend setting your carbs to the basic setting of the version 5 as a starting point.

    Do you have a problem with the running of the engine - do you suspect the carbs, have you checked to see what jets you have in your carbs ?

    Might be worth posting your question in the Technical section, maybe someone from across the pond has some information that can help
     

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