458 ENGINE MOUNT TO A 355 GEARBOX? | FerrariChat

458 ENGINE MOUNT TO A 355 GEARBOX?

Discussion in 'Technical Q&A' started by ExcelsiorZ, Mar 2, 2016.

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  1. ExcelsiorZ

    ExcelsiorZ Formula 3
    BANNED

    Nov 7, 2003
    1,267
    Beverly Hills
    Anyone familiar with the 458 motor enough to know feasibility of mounting the 458 motor to the 355 transaxle with appropriate adapter(s)?
     
  2. INTMD8

    INTMD8 F1 Veteran
    Owner Silver Subscribed

    Jun 10, 2007
    6,815
    Lake Villa IL
    Bolt pattern is different and inside of crankshaft is not splined to drive a 355 input shaft.

    Maybe the thickness of the adapter could be taken up by a splined adapter that bolts to the crankshaft flange.

    Also, the corner of the 458 engine where the starter mounts may interfere with the shift rod. (not the end of the world however since you would be using an F355 starter).
     
  3. PAUL500

    PAUL500 F1 Rookie

    Jun 23, 2013
    3,136
    I have recently been studying the requirements to place a 355 box behind either an FF or 599 engine.

    You need to ditch the flywheel/clutch and starter motor on the engine side, have an alloy adapter plate made up to allow for the different bolt patterns between engine and gearbox plus a machined adapter bolted to the crank that has a splined insert instead of a spigot bearing to allow drive directly to the propeller shaft of the gearbox, this also needs to seal the gearbox oil in, just like the end of the crank on the 355 engine.

    A 458 motor would need all of the above, one of those is possibly plan B for me :)
     
  4. PAUL500

    PAUL500 F1 Rookie

    Jun 23, 2013
    3,136
    Ha great minds think alike at the same time!, good to see the same advice though.
     
  5. INTMD8

    INTMD8 F1 Veteran
    Owner Silver Subscribed

    Jun 10, 2007
    6,815
    Lake Villa IL
    Haha, we are on the same page :D

    Actually I think this would be one of the easiest parts of the project, whether it's a 458 engine going into a 355, a 355 box into a 458 or the engine/trans going into something else altogether.
     
  6. greyboxer

    greyboxer F1 World Champ

    Dec 8, 2004
    12,712
    South East
    Full Name:
    Jimmie
    Would the 355 gearbox be strong enough for the 50 % increase in power & torque of a 458 engine let alone double with a V12 ?
     
  7. PAUL500

    PAUL500 F1 Rookie

    Jun 23, 2013
    3,136
    The weak point of the 355 box appears to be the main shaft from the crank to the flywheel, it seems to snap off at the clutch end on occasion.

    From what I have seen and read this is down to the incorrect heat treatment cycle being applied to the shaft at times from the factory, and could also be due to the sprung flywheel needing re lubing with Kluber grease.

    Solution seems to be to have the shaft re heat treated to greater tolerances, the rest of the box appears very robust, but it is the potentially weakest link in the chain.

    For me I need to use it due to space issues, the transverse box of the 355 is very compact and allows the driveshafts to line up still in my application.

    Of all the available ferrari gearboxes they seem to be the most plentiful and economical to buy which I guess is due to replacements not really being needed as they stand up to a lot of abuse typically.
     
  8. Markphd

    Markphd Formula Junior

    Mar 10, 2012
    713
    With regards to the propeller shaft, it's rather shock sensitive, which could be rectified by partial annealing of the shaft near the clutch end of the shaft to provide more capacity to absorb shock without breaking. The shaft is just too brittle when hardened to the point the factory specified. It does however act in many ways like a fuse which prevents excessive shock loads from ever reaching the transmission (and if that fuse was cheap and plentiful it might be an acceptable compromise - it's neither).
     
  9. ExcelsiorZ

    ExcelsiorZ Formula 3
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    Nov 7, 2003
    1,267
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    Thank you. Yes, was looking at that splined shaft on the 355 gearbox. Definitely an issue. Will look also at the starter location on the 458.
     
  10. ExcelsiorZ

    ExcelsiorZ Formula 3
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    Nov 7, 2003
    1,267
    Beverly Hills
    Interesting. Are you going forward with your concept? Wouldn't the V12 motor want taller gearing given its far greater torque than the 355 for which that gearbox was intended?
     
  11. ExcelsiorZ

    ExcelsiorZ Formula 3
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    Nov 7, 2003
    1,267
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    Yes, compactness of the gearbox is amazing and it is what allowed Ferrari to keep basically the same architecture of a 308 and flip the motor longways within a similar wheelbase. What are you building in front of the gearbox?
     
  12. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    39,318
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    I would think V12 torque would shred an F355 gearbox. Ferrari eventually went to triple cone synchronizers and other tricks to make the V12 transaxles with 400+ lb-ft of torque live.
     
  13. PAUL500

    PAUL500 F1 Rookie

    Jun 23, 2013
    3,136
    Mine is down in the special projects section of fchat, I updated the thread a few days ago :)

    What are you putting together?
     

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