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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 35 Comments
      1. CobraMarty's Avatar
        CobraMarty -
        OK, my vote-

        Attachment 59358
      1. Eleventeen's Avatar
        Eleventeen -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        OK, my vote-

        Attachment 59358
        Looks good. Whatever you decide, you should trademark it! This is a nice mod. Stealthy and simple!
      1. Sticky2's Avatar
        Sticky2 -
        Yeah I just kept thinking MILFS
      1. 93siro's Avatar
        93siro -
        Who wouldn't love a good set of Milfs? Click here to enlarge
      1. Sticky2's Avatar
        Sticky2 -
        Click here to enlarge Originally Posted by 93siro Click here to enlarge
        Who wouldn't love a good set of Milfs? Click here to enlarge
        Depends on their performance...
      1. Payam@BMS's Avatar
        Payam@BMS -
        Yea, I keep coming to this thread in hopes of MILFS Click here to enlarge

        It still doesn't disappoint though LOL
      1. CobraMarty's Avatar
        CobraMarty -
        Picked these up from the machinist.
        Added some Bling.

        Next is to install them on the B58 head and take measurements.
        Each one is machined differently to see which one works better.

        Attachment 59482
      1. CobraMarty's Avatar
        CobraMarty -
        Yes these will work on the 2020 Supra MKV!!
      1. HeadgamesDave's Avatar
        HeadgamesDave -
        that's not the B58 in the Supra or new BMW the exhaust port is integrated. Your local to me, I have one of those heads (that you have) I would have given you the MILV's.

        Everything is the same in the valve train from what I have seen so far, from old B58 to new. The chain is in a different spot so it wouldn't be a bolt on
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        Yes these will work on the 2020 Supra MKV!!
        Any plans to get some numbers or have someone test them on the Supra?
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        Picked these up from the machinist.
        Added some Bling.
        Not sure why your attachment didn't embed:

        Click here to enlarge
      1. Solid67's Avatar
        Solid67 -
        Any updates on this? Would this improve the top end power of the stock b58 turbo?
      1. Sticky2's Avatar
        Sticky2 -
        Click here to enlarge Originally Posted by Solid67 Click here to enlarge
        Any updates on this? Would this improve the top end power of the stock b58 turbo?
        @CobraMarty
      1. CobraMarty's Avatar
        CobraMarty -
        Sorry everyone. I have been swamped with work and no time for the fun projects. I will finally have some time off starting later next week.

        I have 2 parts machined to different specs and will install them and measure the valve lift gains and compare.

        As they will add +1mm to the intake valve lift and 2-3* to the intake duration, I expect that when installed they will add power across the whole power and and top end.
      1. NewbBimmerGuy's Avatar
        NewbBimmerGuy -
        Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
        Sorry everyone. I have been swamped with work and no time for the fun projects. I will finally have some time off starting later next week.

        I have 2 parts machined to different specs and will install them and measure the valve lift gains and compare.

        As they will add +1mm to the intake valve lift and 2-3* to the intake duration, I expect that when installed they will add power across the whole power and and top end.
        Marty, I'm hearing whispers and rumors that with the extra boost pressure from a good tune the stock springs at the upper end of the RPM scale are already at / beyond their limits, more lift makes that problem a little worse. Do you recommend spring upgrades on the intake or exhaust with the MILVS?

        -If so, any chance you'll offer an appropriate spring package?


        Adam