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Oil Pressure valve

in General Tech Discussion 9 years ago
If the mushroom valve for the oil pressure is supposed to be an upgrade and an improvement on the ball bearing, why are new engines supplied with the ball bearing?

Mark

  • Re: Oil Pressure valve

    by » 9 years ago

    The "Mushroom" valve is not now (and never will be) installed as a standard factory part, and in most cases it is not an upgrade - it's an optional substitute part that is only used in certain situations where there can be unusual fluctuations in oil pressure.
      
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  • Re: Oil Pressure valve

    by » 9 years ago

    I have a question or two on this too.
    This may be a minefield.

    Wasn't it required for the TBO extensions on some of the engines?
    If it was thought to be important for the TBO extensions why not on every engine?
    If the ball bearing was thought to cause fluctuations then why leave that up to chance on all engines?
    If just using the ball bearing allowed the spring to deviate against the case wall why use it when the option is better?

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

      
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  • Re: Oil Pressure valve

    by » 9 years ago

    Good questions, Roger. I expect to be opening up a relatively new engine that has the new (recessed head) bolt on the oil pressure regulator, but is experiencing oil pressure fluctuations. While I had, previously, expected to find the "mushroom" valve, even though I am aware that (at least some) engines with the recessed bolt head still have the ball bearing, I now understand that the ball bearing is almost certainly in the oil pressure regulator. After I open it up, I will let you know what I find, and whether the mushroom valve fixes the fluctuation issue. While I am ready and able to hook up a mechanical oil pressure gauge, at this point I wonder whether there's even any reason to do so.

    UPDATE: The engine came from the factory with the "old style" ball bearing. Upon replacing the ball bearing, spring, and bolt with the "mushroom" valve, along with a new spring and new bolt, the fluctuations went away.
      
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  • Re: Oil Pressure valve

    by » 9 years ago

    Some confusion between the mushroom and plug screw here?
    The mushroom is not required for the TBO extension, it is not even mentioned in the TBO service bulletin SB-912-057.
    You only need to replace the plug screw with the taller, teflon coated screw.
    Admin is correct, the mushroom will never be a standard part and it does not make any sense to make it a standard part as it is not required for most installations.
      
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  • Re: Oil Pressure valve

    by » 9 years ago

    Hi Rob,

    I never quite understood the reasoning for this. (The plug screw I fully understand why) They make the ball bearing for years and later on come out with the mushroom style and thought it was better for some reason or they wouldn't have taken the time or effort to design it and then offer it as a substitute over the ball bearing. If the ball bearing never has an issue why develope the mushroom? If Rotax thinks the mushroom will help in some cases why not use it in everything to prevent those cases from becoming reality at anytime during the engine's life. I have installed 40-50 of them. Most seem to stop oil pressure fluctuations and many times have raised the oil pressure about 5 psi.


    Here's the perfect example:
    "UPDATE: The engine came from the factory with the "old style" ball bearing. Upon replacing the ball bearing, spring, and bolt with the mushroom" valve, along with a new spring and new bolt, the fluctuations went away"

    The engine didn't start life this way, but did end up having the issue. Isn't this one reason why Rotax developed the mushroom?


    Is my way of thinking off or I have missed something altogether?

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

      
    Report
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