Toyotec's debunking the myth about 12v VR6, MLS and fibre AAA and AMY head gaskets.

Discussion in 'VR5, VR6 & Wx' started by Toyotec, Mar 21, 2017.

  1. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Years ago, I owned a late model Golf MK3 VR6 from 2009 to 2015. The engine was very faithful and our family put 80K miles in our ownership. During that time naturally I looked after it and even had reason to improve the powertrain.

    Some of my experiences are captured in this thread.

    In that thread post 139 of that thread I made mention of the gasket thickness of the MLS gasket of later 12v engines, as found in vehicles such as the Ford Galaxy 2.8 and VW Sharan within the AMY 12v engine.
    This post seeks to clarify the internet suggestion if the MLS 12v gasket does indeed increase the CR on an early 12v AAA, ABV or AES engine.

    Myths about MLS gaskets and compression increases

    During the refresh of my car's engine, following a suspect blown head gasket, the thickness of the MLS and compressed OE fibre gasket were compared. This would test the claim that the MLS gasket can increase the CR of the VR6 12v motor by 0.5 points.

    The thickness of the used composite gasket was measured with a vernier.

    [​IMG]

    The thickness was found to be 1.68mm on average as measured at various fire rings.

    [​IMG]

    Once complete, this data was put in an excel sheet to calculate compression ratio.

    The same was done for the MLS gasket after.

    VR6 MLS_AMV_Gasket.JPG

    NB


    • All gaskets measured at several points of the cylinder fire rings.
    • Fibre gasket 1.68mm
    • As the MLS was measured before at 1.65mm, a re-measurement of the new MLS was found to be 1.64mm and for the calculator, it was corrected to 1.63mm assuming for clamping force from bolt torque.


    Results from the calculator

    Compressed Victor Reinz Fibre/Composite gasket

    [​IMG]


    MLS VW/Elring gasket (021103383N or 401.820)

    [​IMG]

    Conclusion from actual measurements.

    Yet another myth busted.
    The difference in compression from the use of a MLS gasket is about 0.048, based on the data above and can be considered to have an negligible in pact on cylinder pressure or combustion efficiency when the engine is running.

    Thank you for reading.

    Ed.
     
    Last edited: Mar 21, 2017
  2. razzor13bt New Member

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    I have a Elring MLS gasket p/n 401.820 pic attached.
    We have been using these for years on customers cars and use it for our thicker head gasket shims.
    Std it measures around .8mm thick. Listed as .64 compressed thickness.
    Its listed for the Sharan and T4 Transporters.
    having a problem to attach pics.
    Your gasket used must have been packed or labelled wrong.

    Victor Reihnz 61-34125-00 is MLS 1.6mm thick.
    Elring 401.820 is MLS 0.64mm thick.
    Elring 917.908 fiber type 1.65mm thick.
     
    Last edited: Jul 11, 2023
    RoccoMatt likes this.
  3. razzor13bt New Member

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  4. RoccoMatt New Member

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    Just to add some more noise to this after all these years. I have some brand new Reinz 61-34125-00 gaskets and have just measured 1, uncompressed at 1.2mm. I've struggled to find conclusive data from Reinz on the thickness )not listed in any of their catalogues etc) but this lines up with what I've been able to find spec wise for the AES and AFP engines and lines up with the circa 0.5 CR increase people talk about.

    Interestingly I've seen this gasket part number quoted as having both 1.6/1.65mm and 0.65mm thickness, but nothing official, just in website listings etc.

    I need to get one installed and check it afterwards but suspect it's just 1.2mm as MLS gaskets without a fire ring insert don't tend to change thickness.

    Thanks razzor13bt for the additional data on the Elring gaskets, very useful to know and have options to fine tune CR, along with pistons
     
  5. razzor13bt New Member

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    I actually have 3 gaskets came in this week for another motor we building.
    Will measure with a vernier and take pics again to confirm the last info i posted.
     
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