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    • BMW B58 cylinder head pictures, impressions, and potential for modified intake lift Valvetronic supports

      A ton of great information below from BimmerBoost member @CobraMarty who is known for his MILV's (Modified Intake Lift Valvetronic supports). He recently got a hold of a B58 cylinder head for development and took photos as well as provided his impressions.


      Enjoy:

      Didn't sleep well so I got up early and took a pair of calipers to the B58 head that I have.

      Ports are BIG.
      B58 Intake is Oval shape- 35.7mm tall x 50mm wide. Not 'rectoval' like the N54/N55 at 29mm x 50mm.
      B58 Exhaust is also Oval- 29.2mm x 45.7mm wide. Not round like the N54/N55.

      B58 Valves measure- Intake 29.9-30.0mm, Exhaust 28.4mm.

      N52/N54/N55 Exhaust valves are all 28mm.
      N52 intake valves- 34.2mm, N54- 31.4mm, N55- 32mm.

      So just by 'looks', the B58 head is an improvement.
      Exhaust especially, Bigger ports and Bigger valves = more flow.
      Intake, maybe not so much, Bigger ports and smaller valves.
      IDK, but maybe that combination is better flowing than smaller ports and bigger valves. Or is there another reason or something else going on?

      The intake valves look to be moved out and right at the edge of the cylinder bore. It doesn't look like a bigger intake valve diameter would fit.

      Don't throw stones about the B58's 'smaller' intake valves just yet.

      Interesting is the different engines actual measurements.

      N52- 85mm bore x 88mm stroke = 2996cc and has the biggest intake valve 34.2mm. Cam is I-255*/E-263* durations.

      N54/55- 84mm bore x 89.6mm stroke = 2979cc and have 31.4mm and 32mm intake valves. Cams are N54- I-245*/E-261* and N55- I-255*/263* durations.

      B58- 82mm bore x 94.6mm stroke = 2998cc and has 30mm intake valves which looks to be the largest that would fit the 82mm bore. Cams to be determined.

      There is a correlation between cylinder bore diameter and intake valve size.

      Just some simple, basic engine generalities-
      Bigger bore (bigger intake valve) and shorter stroke make for a higher rev'ing engine. N52 engine.

      Smaller bore (smaller intake valve) and longer stroke makes for better intake filling and more torque and power across a broader rpm range. B58 engine.

      Head- very compact latest design, valvetronic eccentric cam and mechanism moved around, No exhaust cam clamshell like Nxx engines, Heavy, must be thicker in all the right places

      Supports for Intake Valvetronic- up high right on top, easy access, easy removal and replacement, hint MILVs?

      HPFP- mounts up high right on top, easy access, driven by 3 lobed on exhaust cam, easy to upgrade/replace, hint Xtreme DI

      Exhaust ports and close up exhaust port- big oval

      Intake ports and close up intake port- big oval

      Combustion Chamber and close up- very compact

      Valvetronic Eccentric cam Motor- externally mounted, up front, easy access, has hex screw to rotate manually

      Without a doubt, BMW did their homework. The B58 engine looks very promising!!





























      This article was originally published in forum thread: B58 MILVs !! started by CobraMarty View original post
      Comments 29 Comments
      1. CobraMarty's Avatar
        CobraMarty -
        These parts/supports are right on top and easier access. Changing them will be a much easier process.
        1 bolt, remove, replace, tighter, repeat x6 total. Replace valve cover.

        Click here to enlarge
      1. CobraMarty's Avatar
        CobraMarty -
        Ha, the 4 sets that I ordered have to come from Germany.
        I'm sure they are scratching their heads in Germany, thinking- 'these parts never fail', and Why 4 sets?

        At least the head shipped.
      1. CobraMarty's Avatar
        CobraMarty -
        Christmas in August!!
        B58- Cylinder Head

        Attachment 59326

        Attachment 59327
      1. Payam@BMS's Avatar
        Payam@BMS -
        Looking forward to your results!
      1. Sticky2's Avatar
        Sticky2 -
        Could we get more pics of that cylinder head? Like a lot more? Also impressions...
      1. CobraMarty's Avatar
        CobraMarty -
        Didn't sleep well so I got up early and took a pair of calipers to the B58 head that I have.

        Ports are BIG.
        B58 Intake is Oval shape- 35.7mm tall x 50mm wide. Not 'rectoval' like the N54/N55 at 29mm x 50mm.
        B58 Exhaust is also Oval- 29.2mm x 45.7mm wide. Not round like the N54/N55.

        B58 Valves measure- Intake 29.9-30.0mm, Exhaust 28.4mm.

        N52/N54/N55 Exhaust valves are all 28mm.
        N52 intake valves- 34.2mm, N54- 31.4mm, N55- 32mm.

        So just by 'looks', the B58 head is an improvement.
        Exhaust especially, Bigger ports and Bigger valves = more flow.
        Intake, maybe not so much, Bigger ports and smaller valves.
        IDK, but maybe that combination is better flowing than smaller ports and bigger valves. Or is there another reason or something else going on?

        The intake valves look to be moved out and right at the edge of the cylinder bore. It doesn't look like a bigger intake valve diameter would fit.

        Don't throw stones about the B58's 'smaller' intake valves just yet.

        Interesting is the different engines actual measurements.
        N52- 85mm bore x 88mm stroke = 2996cc and has the biggest intake valve 34.2mm. Cam is I-255*/E-263* durations.
        N54/55- 84mm bore x 89.6mm stroke = 2979cc and have 31.4mm and 32mm intake valves. Cams are N54- I-245*/E-261* and N55- I-255*/263* durations.
        B58- 82mm bore x 94.6mm stroke = 2998cc and has 30mm intake valves which looks to be the largest that would fit the 82mm bore. Cams to be determined.

        There is a correlation between cylinder bore diameter and intake valve size.

        Just some simple, basic engine generalities-
        Bigger bore (bigger intake valve) and shorter stroke make for a higher rev'ing engine. N52 engine.
        Smaller bore (smaller intake valve) and longer stroke makes for better intake filling and more torque and power across a broader rpm range. B58 engine.

        Without a doubt, BMW did their homework. The B58 engine looks very promising!!
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        Without a doubt, BMW did their homework. The B58 engine looks very promising!!
        Get me a bunch of pics so I can turn this into an article.

        e-mail me them if you like and I'll take care of the rest!
      1. CobraMarty's Avatar
        CobraMarty -
        Some pics of the head-

        Click here to enlarge

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      1. CobraMarty's Avatar
        CobraMarty -
        So what are these pics and what do I like-

        Head- very compact latest design, valvetronic eccentric cam and mechanism moved around, No exhaust cam clamshell like Nxx engines, Heavy, must be thicker in all the right places

        Supports for Intake Valvetronic- up high right on top, easy access, easy removal and replacement, hint MILVs?

        HPFP- mounts up high right on top, easy access, driven by 3 lobed on exhaust cam, easy to upgrade/replace, hint Xtreme DI

        Exhaust ports and close up exhaust port- big oval

        Intake ports and close up intake port- big oval

        Combustion Chamber and close up- very compact

        Valvetronic Eccentric cam Motor- externally mounted, up front, easy access, has hex screw to rotate manually
      1. Sticky's Avatar
        Sticky -
        You said you ordered four sets of heads.

        Are they all from the same style B58 motor?

        The Supra head obviously will be difference due to the casting but everything else should be the same, right?
      1. CobraMarty's Avatar
        CobraMarty -
        1 head and 4 sets of the B58 Valvetronic suppports to experiment and make MILVs for the B58.

        2020 Supra head looks to be similar everywhere except the integrated 2 port exhaust manifold. I suspect that the 2020 BMW B58 will have the same integrated exhaust manifold.

        The only 2020 Supra head that I have seen is on Papadakis's B58 teardown video. Now if he would only send out that head and get it bench flowed.
      1. Sticky's Avatar
        Sticky -
        A ton of great information below from BimmerBoost member @CobraMarty who is known for his MILV's (Modified Intake Lift Valvetronic supports). He recently got a hold of a B58 cylinder head for development and took photos as well as provided his impressions.

        Click here to enlarge

        Enjoy:

        Didn't sleep well so I got up early and took a pair of calipers to the B58 head that I have.

        Ports are BIG.
        B58 Intake is Oval shape- 35.7mm tall x 50mm wide. Not 'rectoval' like the N54/N55 at 29mm x 50mm.
        B58 Exhaust is also Oval- 29.2mm x 45.7mm wide. Not round like the N54/N55.

        B58 Valves measure- Intake 29.9-30.0mm, Exhaust 28.4mm.

        N52/N54/N55 Exhaust valves are all 28mm.
        N52 intake valves- 34.2mm, N54- 31.4mm, N55- 32mm.

        So just by 'looks', the B58 head is an improvement.
        Exhaust especially, Bigger ports and Bigger valves = more flow.
        Intake, maybe not so much, Bigger ports and smaller valves.
        IDK, but maybe that combination is better flowing than smaller ports and bigger valves. Or is there another reason or something else going on?

        The intake valves look to be moved out and right at the edge of the cylinder bore. It doesn't look like a bigger intake valve diameter would fit.

        Don't throw stones about the B58's 'smaller' intake valves just yet.

        Interesting is the different engines actual measurements.

        N52- 85mm bore x 88mm stroke = 2996cc and has the biggest intake valve 34.2mm. Cam is I-255*/E-263* durations.

        N54/55- 84mm bore x 89.6mm stroke = 2979cc and have 31.4mm and 32mm intake valves. Cams are N54- I-245*/E-261* and N55- I-255*/263* durations.

        B58- 82mm bore x 94.6mm stroke = 2998cc and has 30mm intake valves which looks to be the largest that would fit the 82mm bore. Cams to be determined.

        There is a correlation between cylinder bore diameter and intake valve size.

        Just some simple, basic engine generalities-
        Bigger bore (bigger intake valve) and shorter stroke make for a higher rev'ing engine. N52 engine.

        Smaller bore (smaller intake valve) and longer stroke makes for better intake filling and more torque and power across a broader rpm range. B58 engine.

        Head- very compact latest design, valvetronic eccentric cam and mechanism moved around, No exhaust cam clamshell like Nxx engines, Heavy, must be thicker in all the right places

        Supports for Intake Valvetronic- up high right on top, easy access, easy removal and replacement, hint MILVs?

        HPFP- mounts up high right on top, easy access, driven by 3 lobed on exhaust cam, easy to upgrade/replace, hint Xtreme DI

        Exhaust ports and close up exhaust port- big oval

        Intake ports and close up intake port- big oval

        Combustion Chamber and close up- very compact

        Valvetronic Eccentric cam Motor- externally mounted, up front, easy access, has hex screw to rotate manually

        Without a doubt, BMW did their homework. The B58 engine looks very promising!!

        Click here to enlarge


        Click here to enlarge


        Click here to enlarge


        Click here to enlarge


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      1. maxnix's Avatar
        maxnix -
        Very informative pictures and excellent comments.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        Very informative pictures and excellent comments.
        Best thread of recent memory.
      1. CobraMarty's Avatar
        CobraMarty -
        Here's what 4 sets of new OEM BMW supports directly from Germany looks like.

        And I think that I will have my machinist machine in some 'MILVs' lettering on the top of the supports.

        Attachment 59356
      1. Eleventeen's Avatar
        Eleventeen -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        Here's what 4 sets of new OEM BMW supports directly from Germany looks like.

        And I think that I will have my machinist machine in some 'MILVs' lettering on the top of the supports.

        Attachment 59356
        No need for the “s”, if you are machining it on every piece, since that refers to a set of MILV components. Plus “MILV” will fit perfectly since it’s only 4 characters.
      1. CobraMarty's Avatar
        CobraMarty -
        Found my silver sharpie.

        Attachment 59357
      1. CobraMarty's Avatar
        CobraMarty -
        Yeah but it is MILVs

        Modified Intake Lift Valvetronic Support

        Not pleural.
      1. Eleventeen's Avatar
        Eleventeen -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        Yeah but it is MILVs

        Modified Intake Lift Valvetronic Support

        Not pleural.
        That makes sense, but why don’t you capitalize the S, then?
      1. CobraMarty's Avatar
        CobraMarty -
        IDK, play on letters?

        MILVS or MILVs?

        Should put it to a voting poll, ha. 'Forum Open Group Sourced'. FOGS, you heard it here first.

        Both make sense and have merits.
        Historically it was MILF which was singular or plural. It wasn't MILFs or MILFS. And why leave out the 'to'?

        Probably all capitals as it is probably the easiest for the machinist to do in the end. MILVS.
        OK I've casted my vote.