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    • BMW S58 engine technical document - Specs, bore x stroke, electrical, block material, sump, valve sizes, camshafts, redline, pistons, exhaust manifold, etc.

      BimmerBoost already went over many of the technical aspects of the BMW S58 motor but obviously not to this level of detail. BMW's own internal engine technical document is simply fantastic and covers the motor to a level only true enthusiasts will appreciate.


      It is interesting to note certain details. For example, the oil sump system went to an aluminum pan while the S55 started with a magnesium unit. The S55 shifted to an aluminum design later on in its production cycle. It seems BMW cut costs here.

      Furthermore, the cam specs are basically identical to the B58B30O1. Intake valve diameter, exhaust valve diameter, maximum valve lift, etc., all the same.

      Enjoy geeking out over the technical details.








































































































































































































      This article was originally published in forum thread: BMW S58 internal technical document - Specs, bore x stroke, electrical, block material, sump, valve sizes, camshafts, redline, pistons, exhaust manifold, etc. started by Sticky View original post
      Comments 12 Comments
      1. CobraMarty's Avatar
        CobraMarty -
        Great read.

        2 HPFPs and 350bar, WOW.

        Valvetronic mechanism with intake valve having 9.7mm lift.
        Click here to enlarge- MILVs? I need a set of parts, they seem to be the same as the B58.
      1. maxnix's Avatar
        maxnix -
        Note drop in geometric CR to 9.3.

        Single cooling system now instead of stratified on B58.

        Anyone know in which vehicle the B58B30TU engine (upon which the S58B30T0 is based) is installed?
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        MILVs? I need a set of parts, they seem to be the same as the B58.
        I'm surprised it's the exact same as the B58 in that respect.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        Anyone know in which vehicle the B58B30TU engine (upon which the S58B30T0 is based) is installed?
        No idea. I'm guessing the new X5/X6.

        Edit: Nope, not that.
      1. CobraMarty's Avatar
        CobraMarty -
        As it says, "The design of the valve lift control system has not changed in comparison with the B58TU engine".
        They call the part #4 a 'Gate'.

        Attachment 59137
      1. Payam@BMS's Avatar
        Payam@BMS -
        Full forged internals eh? Pistons, rods, and crank. This is going to be some interesting stuff when people start going larger turbos.
      1. maxnix's Avatar
        maxnix -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        No idea. I'm guessing the new X5/X6.

        Edit: Nope, not that.

        Well, I did see something in Chinese that referenced the B58B30TU mentioning the (presumably new) X6. I am just mystified why BMW would refer to an engine that has not been produced as a predecessor.

        On the other hand, the plumbing in this engine with 3 pumps is daunting, I cannot fathom replacing the plastic parts as they fail.
      1. sahyoun's Avatar
        sahyoun -
        I would'nt call ditching magnesium cost cutting necessarily. Whenever bmw uses magnesium it almost never holds up. Look at the M60/m62 valve covers, they disintegrate before your eyes. The S55 requires the use of rubber screws to help prevent the pan from corroding from being bolted by aluminum. Its not worth the ~2lb weight savings bmw claims. The s58 does look promising though, it seems like they're not taking too many chances with mechanical design just wish the main bearing caps had more than two bolts but im sure it'll be fine.
      1. atorrealba's Avatar
        atorrealba -
        So it's going to basically follow the footsteps of the S55 sharing parts with the N55.

        If thats the case, whats the point of BMW continuing to water down the "M-Factory" parts into regular 3-series. Every M car past the E92 after the F10 M5, including the F80 M3 has officially lost the way if this is the case.

        F80s and F10s are no longer considerably valuable in terms of future-classic potential and will just deprecate into the hands of kid-racer tuners tbh
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        I am just mystified why BMW would refer to an engine that has not been produced as a predecessor.
        I think the confusion stems from them using B58B30TU name instead of the full proper engine code. So TU likely refers to a technical update B58.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by atorrealba Click here to enlarge
        If thats the case, whats the point of BMW continuing to water down the "M-Factory" parts into regular 3-series. Every M car past the E92 after the F10 M5, including the F80 M3 has officially lost the way if this is the case.
        Old news: https://www.bimmerboost.com/content....-in-production
      1. sahyoun's Avatar
        sahyoun -
        Click here to enlarge Originally Posted by atorrealba Click here to enlarge
        So it's going to basically follow the footsteps of the S55 sharing parts with the N55.

        If thats the case, whats the point of BMW continuing to water down the "M-Factory" parts into regular 3-series. Every M car past the E92 after the F10 M5, including the F80 M3 has officially lost the way if this is the case.

        F80s and F10s are no longer considerably valuable in terms of future-classic potential and will just deprecate into the hands of kid-racer tuners tbh

        This is nothing new, look at the m50/m52/s52 family, all share more or less the same rotating assembly aside from a few dimensional changes. They are all forged rods/cast pistons with around the same bottom end power limit. Same goes for the m60/m62/s62. The S58 and B58 have totally different pistons and rods. Crank is likely different as well. Cams are different, the entire head is different. This engine is far more unique to its non-m counter part than the s55 was. By the looks of it, this seems to be the most mechanically overbuilt bmw i6 since the s38 and even that's debatable. I cant think of any bmw engine that came with truly forged pistons from the factory. Combine that with two hpfps and a much higher rail pressure with low compression and it sounds like a beautiful recipe for tuning.