Replacement front cover bearing for '83 308 QV USA | FerrariChat

Replacement front cover bearing for '83 308 QV USA

Discussion in 'Technical Q&A' started by Plutexams, Apr 3, 2020.

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  1. Plutexams

    Plutexams Rookie

    Mar 31, 2018
    21
    Full Name:
    RICHARD R PLUT
    Does anyone know of a replacement bearing for the front cover of an '83 308 QV USA, Ferrari part number 174260? Also, the bearing part number for the USA QV and non USA QV are different. Are they interchangeable? Thanks in advance.
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    34,574
    Austin TX
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    Brian Crall
    #2 Rifledriver, Apr 3, 2020
    Last edited: Apr 3, 2020
    Check your part number. It isn't for a bearing. It is far too high a number for a 308 in any event.

    Also there are 2 possibilities for the 83 308. The inner bearing has 2 possible ODs and it would need to be measured.

    There is no difference mentioned for US and base version.

    If it is the outer bearing you are looking for it is a proprietary size and not commonly available. You won't be getting it from a bearing supplier off the internet.
     
  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,256
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #3 Steve Magnusson, Apr 3, 2020
    Last edited: Apr 3, 2020
    Here is the relevant page from the 1983 US 308QV SPC:
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    The earlier bearings (104918 inner and 112019 outer) are standard sizes (used in production 10/1983 and before).

    The later (larger) bearings (121275 inner and 121274 outer) are the more-difficult-to-get non-standard sizes that Brian mentioned (used in production 11/1983 and after).

    (Note: Usually, they are more specific, giving before and after engine SNs, for when a design change is made, but in this case they just give a date for when each style "crankcase" was made).
     
  4. Plutexams

    Plutexams Rookie

    Mar 31, 2018
    21
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    RICHARD R PLUT
    My apologies for the part number. I had several numbers on the page and wrote the wrong one. I meant part number 121274. From what I gather, it is proprietary. If the US and non US are the same, any idea why they have different part numbers? US, 121274, non-US 175260. From a previous post I saw bearing part number for non-US as SKF 6203-22/C3. Anyone know if this is correct and would work. Thanks much.
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,256
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #5 Steve Magnusson, Apr 4, 2020
    Last edited: Apr 4, 2020
    The US and non-US 308QV part numbers for these bearings (and the design change in these bearings) is exactly the same -- here's the non-US 308QV SPC page for these bearinjgs:

    https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/308-group/308qv/timing-system-controls.html

    The "175260" part number seems to be just an updated PN for the sealed 40mm OD 112019 bearing (at least that's what shown on Ricambi America's website, but, oddly, only for the late 308GT4 SPC, and, even more oddly, the quantity is shown as "1" -- whereas, this same sealed 40mm OD 112019 outer bearing is used on all the late 308 carb thru early 308QV with a quantity of 2). Where are you getting this 175260 PN from?
     
  6. Plutexams

    Plutexams Rookie

    Mar 31, 2018
    21
    Full Name:
    RICHARD R PLUT
    Thanks much for the reply. I now don't know where I got that number. To many numbers on the page. Bottom line, there isn't a replacement for the bearing that isn't Ferrari. Thanks again.
     
  7. 85QVEuro

    85QVEuro Formula Junior

    Jan 15, 2021
    421
    NYC
    Full Name:
    Joe
    Steve - for item 38 in the drawing, part #121279 which goes under the cam drive bearing, does the "conical shape" face up or down when putting it back together?
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,256
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #8 Steve Magnusson, Jan 31, 2022
    Last edited: Jan 31, 2022
    If the ID of the spring washer, 8, is larger than the ID of the bearing outer race as shown on page B37 of the 308QV/328 WSM, I would install it "cone up" (cone faces bearing -- spring washer touches snap-ring at the largest possible diameter):
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    (I'll give them a little engineering demerit for drawing this too accurately with the spring washer deflected into its near-flat shape so that you can't tell which way it goes -- should've been drawn "fudged" to clearly show the physical orientation the conical spring washer.)
     
  9. 85QVEuro

    85QVEuro Formula Junior

    Jan 15, 2021
    421
    NYC
    Full Name:
    Joe
    Thank you and super helpful (you think you are keeping track of everything when you're taking it apart but...)
     

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