complete 308 carburettor strip down and overhaul question | Page 2 | FerrariChat
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complete 308 carburettor strip down and overhaul question

Discussion in 'Technical Q&A' started by Martin308GTB, Dec 20, 2011.

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  1. Sledge4.2

    Sledge4.2 F1 Rookie

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    Geno
    #26 Sledge4.2, Dec 26, 2011
    Last edited by a moderator: Sep 7, 2017
    The bead blasted carb looks really nice.

    when i was rebuilding mine, i decided to experiment on one of my spare carb bodies, and I ball polished it. In the end, it looked too "blingy" for me, and i opted for the natural "yellowish" finish. Your dont look too blingy, but I suspect after a few months of heat cycles they will dull up to the natural finish :)
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  2. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
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    Mitchell Le
    #27 yelcab, Dec 26, 2011
    When I did mine, I just soaked them in carb cleaner and 3 turned out brighter, one was dull. I thought about it, left it alone, and installed them back in the car. After a few miles, I stopped caring what they look like because 1) they always were covered by the air box, and 2) there was always a bit of carburetor gunk after a few miles and they were no longer able to look like new. They did run really nice...
     
  3. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    #28 Martin308GTB, Dec 26, 2011
    I totally agree; but the picture shows a little bit too much of gloss. Either because of the flashlight I used, or because I sprayed the carbs with a small amount of WD-40 to protect them till further assembly.
    Directly out of the blasting cabinet they have a nice satin like, more matte finish.
    I simply enjoy creating a set of carburettors looking like new.
    Next step will be fresh plating of the steel parts. But the company, which will do this for me, is closed till 2nd January. In the meantime I will go on cleaning parts - still a lot to do - and checking small parts.
    So far I have discovered different slow running jets ( 45, 40, 50 ).
    More surprises to come. I hope not too many :)

    Best Regards from Germany

    Martin
     
  4. Ferraripilot

    Ferraripilot F1 World Champ
    Owner Project Master

    May 10, 2006
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    #29 Ferraripilot, Dec 30, 2011
    The 'new' look certainly is rewarding once done.

    I found it a pain reinstalling the butterfly plates to the shaft and getting them to seal as they did before. I got them and and they worked fine but they just don't seem to be as tightly sealed to the bores as before when closed. I checked this by closing the butterflies and shining a bright LED flashlight under to see any light/leaks through any cracks on the sides.


    Also, as an added bonus you could shave down the tops off the throttle plate screws so they do not protrude through the throttle shaft when fully seated. This frees up a few Cfm.
     
  5. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    #30 Martin308GTB, Dec 30, 2011
    Last edited: Dec 30, 2011
    a great idea really, but I don't know whether I will dare this :)
    Do you mean the slotted screw heads - I think so, because you say 'tops' - or the other ends which have to be punched ?

    At the moment I cannot proceed like I would like to, because noone works this week and I need some small parts.
    In the meantime I have discovered, that the seat of the throttle shaft bearings is different. One side is a tight fit, the other a loose fit. Identical on each carburettor. And there is absolutely no visible wear.
    As opposed to many, who think this is a fault and put Loctite onto the loose bearing I think this is correct, because on basically every bearing design one side has to be a fixed, the other side a floating bearing. Due to temperature expansion.
    One shouldn't jam this expansion gluing solid the floating race.
    The inner races are fixed on the shaft, so at least one outer race must be able to float a little bit in axial direction.
    At least this is a basic mechanical engineering doctrine.

    Does anyone have a different opinion ?

    Best Regards from Germany

    Martin
     
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  6. Martin308GTB

    Martin308GTB F1 Rookie

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    #31 Martin308GTB, Jan 10, 2012
    Last edited by a moderator: Sep 7, 2017
  7. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    #32 Martin308GTB, Jan 20, 2012
    Last edited by a moderator: Sep 7, 2017
  8. Sledge4.2

    Sledge4.2 F1 Rookie

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    #33 Sledge4.2, Jan 20, 2012
    wow, that is a work of art! very well done.
     
  9. Peter

    Peter F1 Veteran
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    Dec 21, 2000
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    #34 Peter, Jan 27, 2012
    Superb!
     
  10. ME308

    ME308 Formula 3

    Nov 5, 2003
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    Michael
    #35 ME308, Jan 28, 2012
    great work Martin,

    if I should ever have a carb car, I will gladly send the whole stuff to you for rebuild ;)
     
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