Close

Results 1 to 15 of 15
  1. #1
    Join Date
    Jul 2012
    Location
    On the Road Again
    Posts
    289
    Rep Points
    301.5
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No

    Will reduced oil temps result in less oil vapor in the intake?

    In another thread, I posted how I installed the BMS oil thermostat delete and saw an immediate 30F reduction in oil temps as a DD driving around town with little boost (I.e., no fun). So I'm wondering whether this will result in less oil vapor in the intake? Anybody with an OCC and BMS thermostat delete notice less oil being collected in the OCC with the cooler oil temps?
    2008 E90 335xi AT 58K MILES - FAILING XFER CASE MOUNT
    MHD CUSTOM E50, N20 TMAP, FUEL-IT TBI & STG 2 LPFP, cPE CHARGE PIPE, HELIX IC, FORGE DV, BMS DCI, BMS T-STAT DELETE, BMS OCC, RB PCV, KW-V1 COILOVERS, APEX ARC-8, 235/265 MICHELIN PSS, ALPINA B3 TCU, SCOOPSClick here to enlarge

  2. #2
    Join Date
    Jan 2012
    Location
    Northern VA
    Posts
    111
    Rep Points
    200.4
    Mentioned
    13 Post(s)
    Rep Power
    3


    Yes Reputation No
    Theoretically, yes, lower oil temps will reduce vaporization significantly. I'm running the Dinan OC with oil temps in the 210-220F range on the street driving easily or hard, hot weather, sitting in traffic, etc. Still yet to see track use (Nov at VIR, yes!), probably see 250-270F driving hard.

    What oil are you using? I've used Motul 8100 Xcess 5W40 in many different BMW engines, including lots of N54s, with very low oil consumption and very little oil in the intake, no lifter noise, reduced or eliminated VANOS rattles, etc. Anecdotal at best, but that's what I'd also recommend.
    James Muskopf
    RRT Racing
    2007 E92 335i/6MT Procede Rev3 w/PWM meth, otherwise stock
    E28 M5, R171 SLK320

  3. #3
    Join Date
    Nov 2011
    Posts
    6
    Rep Points
    6.4
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    I posted a similar thread on N54tech...
    http://www.n54tech.com/forums/showthread.php?t=21033

    Seems plausible.

  4. #4
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Yes Reputation No
    I disagree completely! Oil "vapor" is not really oil vapor. Rather its condensation, fuel dillution and blow by gasses that naturally form during the engine operation. Higher oil temperatures allow for those solubles to evaporate and sort of burn off, leaving your oil clean of them.

    Here is an example of an engine that runs very low oil temps from the factory and as a result of that this is extremely common:

    Click here to enlarge

    By burning off solubles, your engine oil stays cleaner for longer and therefore it is able to protect the engine internals for longer. This, combined with high quality synthetics explains the unusually long drain intervals that BMW is recommending. ....not that I follow them anyway...
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  5. #5
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Yes Reputation No
    Try heating up motor oil to 260F. There are absolutely no oil vapors whatsoever. This is not extra virgin olive oil. The smoke point is extremely high on motor oils.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  6. #6
    Join Date
    Jul 2012
    Location
    On the Road Again
    Posts
    289
    Rep Points
    301.5
    Mentioned
    10 Post(s)
    Rep Power
    4



    Yes Reputation No
    @vasillalov, that is the first time I heard this point of view that the oil temps need to be hot to evaporate water and dissolved gases. This does make sense to this chem eng guy! The question then becomes how low is too low? In the VW engine picture you provided (btw, what part was that?) of what happens when the oil temps are too low, what were the temps? I would think a minimum of 100C (212F) would be sufficient to dewater and degas the oil.

    Coincidentally, the E90 N54 manual advises not to go WOT until oil temps have reached a minimum of 210F. I understand this is mainly in connection with viscosity level for maintaining proper lubrication of engine parts at high shear rates.

    Again, thanks for the very informative post!

  7. #7
    Join Date
    Nov 2011
    Posts
    6
    Rep Points
    6.4
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    I disagree completely! Oil "vapor" is not really oil vapor.
    What? What is oil volatility then? And why do oil manufacturers try to hard to fight it with synthetics?

  8. #8
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by e90man Click here to enlarge
    What? What is oil volatility then? And why do oil manufacturers try to hard to fight it with synthetics?

    Any material in the universe will burn and evaporate if heated sufficiently. Even diamonds and titanium.

    The point I am trying to make here is that engine oils are stable within certain temperature range. If the oil temperature is too low water vapors, fuel dilution and other blow-by gasses and chemicals will remain in the engine oil for much longer. They will also react chemically with the oil and each other. Usually, this causes the acidity of the oil to go high, the effective flash point to go down, and the viscosity and lubricity of the oil change.

    The way to combat this is to keep the engine temperature above certain point, so that these "solubles" have a chance to evaporate and burn off by being recirculated through the PCV system into the combustion chamber. What that temperature is depends on each individual engine design.

    There is a reason why our thermostats open at such temperatures. There is a reason why BMW adds additional cooling with the PPK but does NOT change the thermostats.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  9. #9
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Yes Reputation No
    Click here to enlarge Originally Posted by Jeffman Click here to enlarge
    In the VW engine picture you provided (btw, what part was that?) of what happens when the oil temps are too low, what were the temps?
    That's the oil cap. This is on an older NA VR6 engine. Same thing happens with the VW 2.0 8V engines. I've owned one for 6 years and I used to work and tune extensively VW and AUDI engines back in the days. The "milky" oil cap is a result of water vapor that condenses and froths on the oil cap because the engine oils are not hot enough for this to evaporate. This "frothing" is also occurring in the PCV valve, rendering it clogged and thus further complicating the problem.

    The only way to help this is to actually go for a very spirited drive for 30-50 miles. It heats up the engine oil and all the "froth" gets cleared away...

    Now, clearly, this is an extreme example that I am trying to use here to get the point across. While I don't think this will happen to the N54 if you remove the thermostat to this extent, some of the effects I am describing above will be inevitable.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  10. #10
    Join Date
    Nov 2011
    Posts
    6
    Rep Points
    6.4
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    I think maybe the intention here by the OP, and my thread I linked, was to not cool the oil too much, but enough to effectively reduce oil vapor in the intake. Like the OP said, a 30 degree drop in temp would seem to reduce vaporization. It would be nice if we could try to get close to a happy place between proper oil lubrication and water burn-off yet "cool" enough to reduce volatility, and therefore less carbon build up (theoretically).

  11. #11
    Join Date
    Dec 2012
    Posts
    30
    Rep Points
    38.0
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    First, I reversed my stock Tstat and my oil temps have gone down significantly. Secondly, that helped in my hot summers here in Jersey but I won't run it like that during the winter, will change it back soon. I think both points are correct in this way. You want the oil to get up to operating temperature which I believe (don't quote me please) is 212 in order to burn everything off. I would think running the oil at 230-240 is the best possible range. Here in Jersey, or anywhere hot and humid as many of you know pushes the temp up above 250 even with a cooler and 5w-40. They might be too high.

  12. #12
    Join Date
    Jul 2012
    Location
    On the Road Again
    Posts
    289
    Rep Points
    301.5
    Mentioned
    10 Post(s)
    Rep Power
    4



    Yes Reputation No
    Click here to enlarge Originally Posted by jnat Click here to enlarge
    First, I reversed my stock Tstat and my oil temps have gone down significantly. Secondly, that helped in my hot summers here in Jersey but I won't run it like that during the winter, will change it back soon. I think both points are correct in this way. You want the oil to get up to operating temperature which I believe (don't quote me please) is 212 in order to burn everything off. I would think running the oil at 230-240 is the best possible range. Here in Jersey, or anywhere hot and humid as many of you know pushes the temp up above 250 even with a cooler and 5w-40. They might be too high.
    Hey jnat, I hear you. I may put my Tstat back in, too, but after my experiment....you can't argue hard data...
    I'm going to send a sample into Blackstone for oil analysis after a total of 500-1000 miles with Tstat delete, and then do the same after I reinstall the Tstat. If the first test shows more "junk" (e.g., fuel) in the oil than the second test, then we have our answer- and Vasillalov would be correct! Tests are about $25 each and I am more than happy to do this. Stay tuned!

  13. #13
    Join Date
    Dec 2012
    Posts
    30
    Rep Points
    38.0
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    Cool, can't wait to here results!

  14. #14
    Join Date
    Nov 2010
    Posts
    404
    Rep Points
    758.8
    Mentioned
    11 Post(s)
    Rep Power
    8


    Yes Reputation No
    I suspect running a low VOC (volatile organic compound) will help more than modestly lowering normal oil operating temps.

    FWIW, I use a BMS occ and Rob Beck's upgraded PVC. In addition, the Blackstone oil analyses I've done over the last 40,000+ miles and 50+ days on road race tracks suggests that a good quality synthetic has no problem with high temps.

    Before going with a custom oil cooler set-up (with a 32 row Setrab), I'd regularly see oil temps of 285-290
    and there was not oil breakdown whatsoever according to the analyses. Mind you, my oil change intervals were excessive, generally in the 3,000 - 5,000 range.

    I usually run Motul 8100 5W40 or Motul 300V 10W40, but I've also run other good qualilty synthetics.

    I'm considering doing the stock thermostat delete but am waiting for Improved Racing to come up with a 210 degree version.

    Neil

  15. #15
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Yes Reputation No
    I run Valvoline Synpower 5W-40. I also have the Rob's PCV valve. It has absolutely no effect on the oil consumption. My OEM PCV valve was just as good.

    What I would like to see on the market is a way to manually bypass the thermostat with a valve and go to the track. For the rest of the time, the valve will be redirecting the oil through the OEM thermostat.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

Tags for this Thread

Bookmarks

Posting Permissions

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