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flat crankshafts...

Discussion in 'Technical Q&A' started by psmaia, Mar 21, 2008.

  1. psmaia

    psmaia Karting

    Oct 26, 2005
    219
    greenwich, conn.
    Full Name:
    Paul Marchese
    i know that the v8's have flat crankshafts, but what about the v12's?..anyone know?..
     
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  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    21,407
    Texas
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Mar 21, 2008
    Last edited by a moderator: Sep 7, 2017
  4. psmaia

    psmaia Karting

    Oct 26, 2005
    219
    greenwich, conn.
    Full Name:
    Paul Marchese
    sorry to be a pain in the a**, but what is interlaced cross bank firing..?
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    21,407
    Texas
    Full Name:
    Steve Magnusson
    No trouble, but it means just what it says (you changed the words a little?).

    Interlaced alternate bank firing = cylinder firing events alternate in occurrance from bank to bank (so the time between the exhaust pulses in each bank is exactly the same, and it sounds cleaner/sweeter/more pure), and on most F, the two banks are offset by 1/2 the time period between firings in the same bank so it goes L-R-L-R-L-R-L-R and the time between all the pulses is the same too (they fudged this second part a little on the 65 deg angle V12 for packaging reasons). If you map out a US 90 deg V8 using a cross-plane crank, it goes something like R-R-L-R-L-L-R-L so, even though the time between all firing events is exactly the same, the time between the exhaust pulses entering each manifold is not the same -- so it sounds a little more jumbly/rumbly/mixed.

    Try a search on "alternate bank firing" and read those threads for a lot more.
     
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  7. psmaia

    psmaia Karting

    Oct 26, 2005
    219
    greenwich, conn.
    Full Name:
    Paul Marchese
    thanks...that was the best explanation i have ever gotten...
     

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