Results 1 to 9 of 9

Thread: Speculation of a Project Car - 1991 850i v12

  1. #1
    Join Date
    Dec 2018
    Location
    Owensboro
    Posts
    6
    My Cars
    2020 BMW M2 Competition

    Speculation of a Project Car - 1991 850i v12

    So with retirement coming a bit early, I've set my sights on a project car to rebuild and upgrade over the next few years.

    The Target, 1991 BMW 850i, V12 5.0 -- I've been looking at buying one for a while, but might actually take the plunge in the new future.
    Now this car has two 2.5L IC M20 Six Cylinders essentially bolted together which each engine having their own respective systems for redundancies.
    Collectively producing around 300HP -- but what if we could get more?

    I've noticed that the early 2000's X5 3.0i's are becoming more and more prevalent in scrap years and auto auctions... so why not buy two, pull the engines and rebuild them in the same fashion for an engine swap in the 850i? Bringing two M54 Engines together to make a 6.0L V12

    Am I crazy? Please give your thoughts!

    Thank you.

  2. #2
    Join Date
    Mar 2004
    Location
    USA
    Posts
    3,241
    My Cars
    96 328is 6.0L
    Crazy? No. Ambitious? Yes. Obviously it's not as simple as it sounds and you need pretty fat retirement checkbook and A LOT of engineering/machinig skill. If you are not planning on doing engineering/machining yourself than that checkbook need to be even fatter.

    If you havent seen yet, lookup LS12 to get idea on what is envolved on "mating" two engines together.
    - 96 328is 6.0L. (LS1 to LS2 build thread: http://forums.bimmerforums.com/forum...ad.php?2098938)
    - 96 328is 5.7L. (LS1 build thread: http://forums.bimmerforums.com/forum....php?t=1289987)
    - 95 ///M3 6.0L. (LS2 build thread: http://forums.bimmerforums.com/forum....php?t=1619249)

    - 97 ///M3. (e46 Fender Flares/track car build thread: http://forums.bimmerforums.com/forum....php?t=1727098)
    - 96 328is (Dual Fuel Pump to Surge Tank thread: http://www.bimmerforums.com/forum/sh...ad.php?1964025)

  3. #3
    Join Date
    Mar 2011
    Location
    PNW
    Posts
    935
    My Cars
    LS E46
    What? I’m not sure you understand how engines work. Don’t quit your day job just yet.

  4. #4
    Join Date
    Mar 2011
    Location
    Dallas, TX
    Posts
    765
    My Cars
    2008 535i
    Unless you have 6 axis cnc to make you a new block forget it. The engines are not bolted together. It's a single v12 engine block with borrowed valvetrain and head geometry from the 6's.

  5. #5
    Join Date
    Mar 2007
    Location
    Norton, OH
    Posts
    4,358
    My Cars
    2019 Miata RF, 88 325i
    Quote Originally Posted by Feiht View Post
    Am I crazy?
    Yes. That's not how any of this works.

  6. #6
    Join Date
    Oct 2014
    Location
    Mesa AZ
    Posts
    242
    My Cars
    2000 740iL
    Quote Originally Posted by Kaane View Post
    Unless you have 6 axis cnc to make you a new block forget it. The engines are not bolted together. It's a single v12 engine block with borrowed valvetrain and head geometry from the 6's.
    Just for the record, the machine work could be done on a 3 axis cnc machine. If a guy were to get a raw casting, any engine machine shop with no could do the finish work on it, and even without a cnc machine.

  7. #7
    Join Date
    Dec 2009
    Location
    Detroit
    Posts
    447
    My Cars
    E36 Compact,Coupe,E30
    Quote Originally Posted by Kaane View Post
    Unless you have 6 axis cnc to make you a new block forget it. The engines are not bolted together. It's a single v12 engine block with borrowed valvetrain and head geometry from the 6's.
    Gahh we were born too soon for additive manufacturing/3D printed engine blocks from our local print shop. Semi serious there are "printers" large enough to make a block out of various metal mediums, but I have a lack of understanding how "strong" the block would be. Maybe if it were to be sleeved it could work in theory.

    OP - Rebuild the stock motor and do some small upgrades. Even a restoration will take someone years and longer if learning all the skills along the journey. If you want a high NA v12 there are a few companies for 50-100K that will build you a full spec race motor NA from that BMW V12.
    S52 E36 Compact
    E36 325is Coronaproject
    08 Saab 9-3 in Oxford Green

  8. #8
    Join Date
    Oct 2014
    Location
    Mesa AZ
    Posts
    242
    My Cars
    2000 740iL
    Quote Originally Posted by ZEKTI View Post
    Gahh we were born too soon for additive manufacturing/3D printed engine blocks from our local print shop. Semi serious there are "printers" large enough to make a block out of various metal mediums, but I have a lack of understanding how "strong" the block would be. Maybe if it were to be sleeved it could work in theory.

    OP - Rebuild the stock motor and do some small upgrades. Even a restoration will take someone years and longer if learning all the skills along the journey. If you want a high NA v12 there are a few companies for 50-100K that will build you a full spec race motor NA from that BMW V12.
    There are Aluminum alloys in the powderbed metal fusion process that can be printed so that it is considered as good or better than cast aluminum. I have not yet seen a machine though that is large enough to print a v12 engine block. Maybe a motorcycle or lawn mower block though.

  9. #9
    Join Date
    Dec 2018
    Location
    Owensboro
    Posts
    6
    My Cars
    2020 BMW M2 Competition
    Hey guys, so thank you for the mixed responses -- sorry it took me so long to get back here.

    I will do some research on the LS12 and see what I can come up with -- I recently learned the stock engine that is in the 850i that I am looking at purchasing has been religiously maintained over the last 28 years. So I am less hellbent on overhauling the engine situation, contemplating on perhaps a supercharger instead for this particular one. (Open for suggestions on what you guys would do)

    Should another large body BMW with a LARGE engine bay pop up with a less than spotless maintenance record, it will find itself as an overhaul project.

    And yes, you're right -- I don't know EXACTLY how all the internals of the engines being mashed together work -- not yet anyways.
    In regards to mechanical background... self taught for the most part, some certification classes, but I grew up around it. Eager to learn.
    Have access to a full service shop so any heavy lifting etc that would need to be done or specialized tools will be good to go there...
    Also have access to a facility and services of a family friend that does full industrial machine work... should I need to down the line.

    Just trying to get some ideas. Thank you all again for your input.

Similar Threads

  1. E31 1991 850i-6 speed project car
    By tvjake2 in forum 8 series
    Replies: 1
    Last Post: 09-16-2015, 07:43 PM
  2. Replies: 7
    Last Post: 05-14-2015, 10:09 PM
  3. Another Project Car ('92 850i 6spd)
    By rcrad6653 in forum Parts for Sale
    Replies: 19
    Last Post: 10-15-2010, 05:40 PM
  4. 1991 850i V12 - Yellow
    By wba1981 in forum 7 series
    Replies: 0
    Last Post: 08-18-2010, 08:47 PM
  5. 1991 850i Black on Black auto parts car ish.
    By Jefjsi in forum 8 series
    Replies: 30
    Last Post: 10-02-2009, 03:00 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •