348 and 355 single disc clutch interchangable? | FerrariChat

348 and 355 single disc clutch interchangable?

Discussion in '348/355' started by plugzit, Aug 23, 2013.

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  1. plugzit

    plugzit F1 Veteran
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    Does anybody know if these are interchangable? For sure??? (Just the disc)
     
  2. Samy

    Samy Formula Junior

    Dec 2, 2005
    603
    Did you already got a answer to your question?

    I have both gearboxes and pumpkins here but dont had time to check if it is interchangeable. I also thought about using a 355 clutch maybe even flywheel and pressure plate on the 348 gearbox. I will tomorrow check if the clutch spline is the same ( i think it is ). And i can messure thickness and diameter of the disc.

    Samy
     
  3. mad dog

    mad dog Formula Junior

    Jan 5, 2006
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    andrew
    They are a different thickness but share the same diameters and hub. So you would need to take some material off. I think the 348 is also a little lighter construction which could only be a worry going the other way perhaps.
     
  4. Samy

    Samy Formula Junior

    Dec 2, 2005
    603
    #4 Samy, Sep 15, 2013
    Last edited: Sep 15, 2013
    I got the sizes out of the workshop manuals

    348 : 247.00 mm x 8.00 mm
    355 : ???.?? mm x 8.30 mm

    I think on that low difference it could be used. It will maybe loose some of pressure in the early lifetime due to the bit bigger thickness and over stretched pressure plate but will soon go on normal ratings. If the pressure plate is used maybe it also lost already 0.1-0.2mm wich would make the difference lower.
     
  5. mad dog

    mad dog Formula Junior

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    early size is

    8.3mm + or – 0.3 at rest.
    7.7 under pressure.
    wear limit 1.5mm

    It was changed in 1999 to 8.9 mm thickness.
    This gives more wear and has a greater tolerance. Unless you tell us otherwise, this is what we use:

    At rest 8.9 + or – 0.3 mm
    under pressure 8.3
    wear limit 2mm.
     
  6. Samy

    Samy Formula Junior

    Dec 2, 2005
    603
    Ok that looks like the early clutch is similar to the 348 clutch. But the new one is much thicker. Did they change the pressure plate on the new 8.9mm type also?
     
  7. mad dog

    mad dog Formula Junior

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    The pressure plate is essentially the same, with just a little adjustment to accommodate the extra thickness. what changes - and I dont know why - is the strength of the finger springs. you can tell which set you have from a letter stamped underneath Z is the stronger. But same size in 348 and 355.
     
  8. ernie

    ernie Two Time F1 World Champ
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    Here is another question.

    What about the flywheels? Could you change a dual clutch to a single clutch and still keep the dual clutch flywheel???? Or are the flywheels different between the two?
     
  9. plugzit

    plugzit F1 Veteran
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    Only the facing plate is different. Now, back to our originally scheduled program.....
     
  10. ernie

    ernie Two Time F1 World Champ
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    Right on, thanks Bruce.
     
  11. Samy

    Samy Formula Junior

    Dec 2, 2005
    603
    Ok then it should be easy to use a 355 clutch disc in the 348 pumpkin with 348 pressure plate. Just grind down the pressure plate 0.9mm and it should fit. Or put a small space plate under the pressure plate (where it is bolt to the flywheel).


    At the moment my plan is to use the hole 355 flywheel , clutch, pressure plate, throw out bearing and hub. That would atleast give some of my 355 gearbox bits a task. Because i still miss the shifting gate and shift rod to use my 355 gearbox in the 348. But to use these parts in the 348 there is one problem the starter gear sits lower on the flywheel and not on the pressuer plate :D. But maybe i can raise it up?

    But what is your plan Plugzit why you ask if it is interchangeable ?
     
  12. plugzit

    plugzit F1 Veteran
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    I have a new 348 pplate and a new 355 disc I'm selling. Wondering if I can sell as a set for a 348.
     
  13. Samy

    Samy Formula Junior

    Dec 2, 2005
    603
    ah ok , i would say if you messure 8.0mm thickness it should be possible. On 8.9mm only if you machine 0.9mm off.
     
  14. mad dog

    mad dog Formula Junior

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    Is it worth us swapping out one or the other? I'll check what stock we have but think I'd do you a 355 PP for the 348. (We had a 348 pp with pretty damaged fingers last week that needs replacing) although postage may make it unworkable.
     
  15. Bucci

    Bucci Karting

    Jan 5, 2020
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    So is there a how to video or post showing how to go from double disk to single disk in the 348?
     
  16. fatbillybob

    fatbillybob Two Time F1 World Champ
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    The dual disc pack and the single disc pack are discrete. You either have a dual or single unit and they are plug and play
     
  17. Ferrarium

    Ferrarium F1 Veteran
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    To switch you would need to switch fly wheels and a few bits, Andrew from MD Clutches in this post used to sell a conversion kit before closing doors. At this point what you have is what you have. Try pricing an OEM flywheel.
     
  18. Bucci

    Bucci Karting

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    No thanks I’ll stick with my duel.
     
  19. Ferrarium

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  20. KevZep

    KevZep Formula Junior

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    I think you have that backwards, the single was the upgrade.
    At 300 hp a twin plate clutch is completely unnecessary which is one reason they changed to a single plate, the other being a Lighter pedal, simpler and cheaper clutch without compromising performance....
    My car is a 1993, and it has a single plate AP clutch. The earlier single plate clutches were Valeo and at some point along the line changed to AP.
     
  21. m.stojanovic

    m.stojanovic F1 Rookie
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    I would not call it "upgrade". If the change was because twin plate was an over-design for 300 Hp, then it was a downgrade to what is adequate/sufficient. However, I agree with Eric that we should call it "not an upgrade" to avoid the negative impression.
     
  22. KevZep

    KevZep Formula Junior

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    I would agree with that, your statement is a more correct way of explaining it.
     
  23. Ferrarium

    Ferrarium F1 Veteran
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    Its like upgrading to a 2 bolt mail from a 4 bolt main to save weight.
     
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  24. KevZep

    KevZep Formula Junior

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    There's no point in having a twin plate clutch if its not necessary, that's all I was saying. You can have a heavy clutch pedal if you want, but there is no advantage at all to having one.
    So, in a way, having a lighter clutch pedal, which ultimately makes the car easier to drive, is in a way, an upgrade.....
    Ive had the AP twin plate clutches in all my race and rally cars which is where they needed, they are not needed in a 300hp road car which is why Ferrari changed to single.
     
  25. Ferrarium

    Ferrarium F1 Veteran
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    #25 Ferrarium, Jul 31, 2020
    Last edited: Jul 31, 2020
    Understood, we all agree.
     
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