S.S.Bearing- What to Do about it??

[Dave Smith]

Eric:   Maybe this is a dumb question,but:- if the bearings are truly sealed,what good does after run oil do??

Regards,,,,,,,,Dave

  ----- Original Message ----- 
  From: Henderson,Eric 
  To: discussion at nsrca.org 
  Sent: Tuesday, August 05, 2003 5:44 PM
  Subject: RE: S.S.Bearing- What to Do about it??


  What is most curious are the vastly different numbers of runs we all get depending upon fuel and props etc. 

  I do know that my Hannos ran longer than the almost identical OS 61 rear exhaust with pump. I was told it was an electrolytic problem that was solved with differing metals. Hmmm.

  I do know that I see dry bearings when I do immediate diss-assemblies. The alcohol stuff evaporates and leaves dry oil??

  So far the only two fixes that have worked are Sealed bearings and SS with lots of oil between sessions. Watch out for sealed bearings though. The rubber can swell and mess up your power and idle.

  Only thing that I do that I have not mentioned is I severely duct the air over the main bearing on all my OS's. They run at about 78F all day. Heat is clearly the enemy. The Japanese told me this and go so far as to run 10%. 

  I have a case of 10/16 that I will test on the next 1.60 motor that I run.

  E.


  -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of Wayne Galligan
  Sent: Tuesday, August 05, 2003 4:30 PM
  To: discussion at nsrca.org
  Subject: Re: S.S.Bearing- What to Do about it??


  Verne,

  So what is the oil content of the fuel your are using?  I use Cool Power 15/17 and the original set of bearings lasted about 125 flights.

  WG

    ----- Original Message ----- 
    From: Verne Koester 
    To: discussion at nsrca.org 
    Sent: Tuesday, August 05, 2003 2:54 PM
    Subject: Re: S.S.Bearing- What to Do about it??


    Bob,
    The general consensus of pilots I talked to at the Nats (many of whom were long time competitors) was that the engine should have less oil, not more. The general idea was that more oil causes the balls to skid instead of roll. However, little or no oil, which was the case with my engine, causes the bearing to deteriorate rapidly. So far, the sealed, EFI bearing has worked just fine. 

    Verne


      ----- Original Message ----- 
      From: Bob Pastorello 
      To: NSRCA 
      Sent: Tuesday, August 05, 2003 7:17 AM
      Subject: S.S.Bearing- What to Do about it??


      Assuming that OS doesn't offer a solution to lubrication of the rear bearing on the 1.40, what other options are available?
          What mods could be made to the crankcase to permit more oil flow back there?
          Would increasing oil content of fuel make any difference?

      If the real core problem is undersizing of the bearing for the load application the motor endures, then a real fix would be a redesign of the crankcase to use a larger and wider bearing.  Pretty unlikely that would happen, I would guess.
          So what's the solution besides keeping the bearing suppliers well-funded??

      Bob Pastorello, Oklahoma
      NSRCA 199, AMA 46373
      rcaerobob at cox.net
      www.rcaerobats.net


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