[SPAM] Re: [SPAM] Re: A Bearing Tip - Boca Bearing Newsletter

[Grow Pattern]

By all means leave in the seals on sealed bearings. 

Be careful, however, if you are using shielded bearings. The metal type shield is not a seal. The bearings come lubricated with grease. When it heats up this grease gets out of the shields and does cause problems. It will make its way to your tank or carb. depending upon your fuel tank pressurizing system. I have seen the grease come out of the carb intake! Also it does not get replaced by oil if the shield is still there.

I have run these bearings with and without shields. If they are stainless they do just fine with one shield removed. I leave the cage and ball-bearings exposed to the crankcase fuel mix.

BTW - even sealed bearings can get too hot. I have seen the seals swell and prevent idle due to "rubbing" against the crankshaft counter balance.

Regards,

Eric.
  ----- Original Message ----- 
  From: Wayne Galligan 
  To: discussion at nsrca.org 
  Sent: Friday, May 20, 2005 2:23 PM
  Subject: Re: [SPAM] Re: [SPAM] Re: A Bearing Tip - Boca Bearing Newsletter


  I have been using the Bearings Limited bearing from Purvis and they are steel with seals and I just leave the seals in.  So far about 300 flights my OS  engine and no signs of problems.  So I think if you go with the stainless and leave the seals in they should go far a long time like the others have stated. The first time I used the Bearings Limited version I took the seal out and the bearing only lasted about 30 flights.  

  I have to raise a point here about the issue of taking the seal out.  If you take the seal off the front part of the bearing leaving the rear seal in it is still a sealed bearing because the front of the bearing will be sealed by the crankcase itself.  As Bob's post states "shield"  this could mean the bearing is not truly sealed.

  I am willing to bet that next time I change my sealed bearing that I could remove one of the seals and there will still be lube in it.   We use sealed bearings in many applications that do not require any outside lubrication influence, i.e.  alternators,brushless motors(20k plus rpm),fan motors, wheel bearings.    

  I am convinced the rust is the number one contributor to bearing failure and load being secondary.   
  I run two head shims so this could also be the reason my bearings are holding up better then some.

  Wayne G.

    ----- Original Message ----- 
    From: Rodney Tanner 
    To: discussion at nsrca.org 
    Sent: Friday, May 20, 2005 10:33 AM
    Subject: [SPAM] Re: [SPAM] Re: A Bearing Tip - Boca Bearing Newsletter


    Thanks Verne,
    That is what I had heard. 

    Rodney Tanner.

    Verne Koester <verne at twmi.rr.com> wrote:
      Rodney, 
      If you're putting it in an O.S. 1.4, definitely leave the seals in. You'll get 300-500 flights with the seals in. With them out, you'll be lucky to put 5 gallons  through the engine before they're shot!

      Verne Koester
        ----- Original Message ----- 
        From: Rodney Tanner 
        To: discussion at nsrca.org 
        Sent: Thursday, May 19, 2005 10:33 PM
        Subject: [SPAM] Re: A Bearing Tip - Boca Bearing Newsletter


        Bob, So using an OS 140 EFI bearing, is it advisable to remove the seals?
        Rodney

        Bob Pastorello <rcaerobob at cox.net> wrote:
          Since I use theirs, I get this e-newsletter.  This month's tip;
          <<If your Front engine bearing has two rubber seals you should not remove them. These bearings have their own grease and can help stop oil leaks. If your bearing has two shields, we recommend you remove one of them. For instructions on removing your shields take a look at this Help Section.

          Your Rear engine bearing should be open on both sides to allow as much fuel as possible to pass through and act as a lubricant. You may however want leave one shield on in the rear which would help to protect the rest of the engine from any foreign matter getting through. This should not be done with one seal. If you find your engine is stingy in getting fuel to the rear, you should definitely leave the bearing open.
          In our next issue of the Boca Bearings Tips & Advice Newsletter we will show you how to remove your bearing shields. >>

          Note - if you open your crankcase, using sealed bearings, and the crankshaft counterweight it dry-looking, or the lower part of the bearing isn't pooling oil, you may think about removing the seals.  I do, for this reason.


          Bob Pastorello
          www.rcaerobats.net
          rcaerobob at cox.net
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