Did you know new BMW V8s are hard-anodized?

Discussion in 'OT Driven' started by deusexaethera, Jan 22, 2009.

  1. deusexaethera

    deusexaethera OT Supporter

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    Basically that means the outer few nanometers of the cylinder walls have been converted from aluminum to aluminum-oxide ceramic; there is no steel liner, unlike in most other engines.

    Aluminum-oxide is the hard white ceramic used in porcelain and in ceramic bearings; it's much more abrasion-resistant than steel, to say nothing of bare aluminum. Also, because of the porous surface of the aluminum-oxide, it holds an oil film far more effectively than any bare metal does.

    So basically, the cylinder walls will never ever wear down -- as long as the engine doesn't get the shit beat out of it every day, anyway.
     
  2. Bugalu

    Bugalu OT Supporter

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    ok.................
     
  3. Bugalu

    Bugalu OT Supporter

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    Just wondering if their was actualy a point to your thread, or your just trying to show off some info that you just read about, like normal.
     
  4. Bugalu

    Bugalu OT Supporter

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    In other words, their is no point to the thread and you are just trying to show off something you read off the internet....
     
  5. deusexaethera

    deusexaethera OT Supporter

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    No. I was trying to start a discussion. About BMW using ceramic-coated engine blocks, specifically. Thanks for fucking it up.

    And people say I'm a troll. What the fuck were you doing, hmm?
     
  6. zumin3k

    zumin3k New Member

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    Seems like the point of the post was to inform people of this information. Which he did. STFU. Sounds pretty cool though.
     
  7. dr.zed

    dr.zed DR.ZED OT Supporter

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    After working on steel liners on LSx engines, this info is pretty cool indeed.
     
  8. art_VW_shark

    art_VW_shark OT Supporter

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    pretty interesting question man, I just don't know that many here would know an answer
     
  9. deusexaethera

    deusexaethera OT Supporter

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    The reason I thought it was cool was because I remember any number of news articles from the 90's about how such-and-so was developing a ceramic engine block that wouldn't need watercooling because it's so heat-efficient, and would run for 500,000 miles before needing resurfacing, but none of those ever came to pass.

    Presumably, that's because you don't really want an engine to be able to conduct heat out of the cylinder really effectively, since it's that heat that drives the pistons in the first place, and pure ceramic tends to be really brittle even when synthetically-manufactured.

    However, a microscopically-thin coating of ceramic would be very effective at least for preventing wear without needing exotic and/or heavy materials (like carbide or steel), and even though it might crack over time, it wouldn't flake off.

    I hear this is the engine BMW will be using in place of the turbo I6 in the future. Can anyone confirm?
     
  10. Priest Tango

    Priest Tango Custom User Tits

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    arent they floating cyl walls too?
     
  11. Cachee0

    Cachee0 OT's Technical Recruiter, Send me your resume

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    Yes but nobody likes you so they will pick on you:fawk:
     
  12. deusexaethera

    deusexaethera OT Supporter

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    This isn't elementary school.
     
  13. deusexaethera

    deusexaethera OT Supporter

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    I'm not sure what you mean. As far as I know, they're cast as part of the block itself.
     
  14. Cachee0

    Cachee0 OT's Technical Recruiter, Send me your resume

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    No man assholes in elementary got a beat down, your behind your computer.
     
  15. Priest Tango

    Priest Tango Custom User Tits

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    the cylinder walls arent solid, they have coolant run artound the cylinder walls. forgot the proper name for it
     
  16. Mr3GTP

    Mr3GTP OT Supporter

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    O motherfucking HI-O
    Wet liners? Like a heavy truck engine? Well, except for Mack, that is...


    Or just water jackets?
     
  17. art_VW_shark

    art_VW_shark OT Supporter

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    I assumed that was how all engines did heat exchange:mamoru:
     
  18. just_another_on

    just_another_on New Member

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    I can't even stand this Deux kid from what i've read in previous posts, but AWESOME Thread.

    Was reading about this shit in the Car Lounge. The new 740i and 750i are really stepping the game up for long term engine reliability.
     
  19. deusexaethera

    deusexaethera OT Supporter

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    Maybe it's a matter of whether the cylinder walls are completely surrounded by coolant, as opposed to just having coolant channels that run near them.

    Given aluminum's high heat expansion rate, I could see why they would want to uniformly cool the entire cylinder wall, to avoid hotspots that would cause the walls to bend and wear unevenly as the engine ages. However, I don't know whether they actually do that or not.
     
  20. turbodan

    turbodan OT Supporter

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    Ceramic is a very poor conductor of heat. You've got it backwards.

    Water cooling is neat because it allows you to carefully control the temperature of the engine block. Engines run most efficiently at slightly higher temperatures than they make the best power.

    I've never heard anything about ceramic engine blocks or anodized aluminum BMW V8's. I'm actually pretty sure BMW still uses plated aluminum cylinder bores in thier V8's. Anodizing just wouldn't last.
     
  21. ZCP M3

    ZCP M3 Active Member

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    sweet.
     
  22. deusexaethera

    deusexaethera OT Supporter

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    Ceramic is an excellent conductor of heat. Among other things, that's why it's used for coffee mugs. Aluminum oxide might not be the best conductor of heat, but in thin layers it doesn't pose a huge problem.

    Excuse me for bringing in a totally off-topic example, but I've owned a couple of expensive flashlights in the past, made of aluminum with military-spec hard anodizing on them, and the anodizing was strong enough that I could (and did) drop it on concrete and then step on it while trying to pick it up, and while the underlying aluminum was dented, the anodizing wasn't even scratched.

    Open-pore anodizing (not dyed and then sealed to prevent dye loss), combined with a coating of oil (which sticks to the anodizing better than bare metal), lasts damn near forever.

    http://en.wikipedia.org/wiki/Anodizing#Anodized_aluminium
     
  23. m3m750

    m3m750 Kickin' it old school

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    Umm, if ceramic were an excellent conductor of heat, wouldn't that make it a bad material for a coffee mug? You'd burn your hand every time you went to pick up the mug.
     
  24. jim1234664

    jim1234664 New Member

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    lol owned, I swear to god I hate how this kid always assumes he is right :squint:
     
  25. pedM5

    pedM5 New Member

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    ceramic is a good dissipater of heat, lot's of brake pads have ceramic compounds in them, when your brakes get hot you can end up warping something, so keeping temps down is the main purpose of putting in a ceramic compound.
     

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