How sealed is a sealed bearing

I have an oily problem with a dynamo on an old engine. Oil leaks from the engine, past the drive gear, lubricates a ball bearing (which it
is supposed to do), defeats a felt seal and then soaks the dynamo windings.
If I replace the ball bearing (an RLS4) with a sealed version will this stop the oil flow and negate the need for the felt seal? I figure that if the seals can keep the lubricant in the bearing then they should be stop the oil even getting to the felt seal let alone the windings.
Comments?
Charles
http://www.homeworkshop.org.uk
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On Tue, 15 Jul 2008 13:17:13 +0100, Charles Ping

Charles
    I suspect a modern 'sealed' bearing will significantly reduce the oil flow through the bearing. However, another option I know to have been successfully used in similar situations is for the felt to be immersed in hot tallow (candle fat) prior to installation!
    It's worked for me in the past when it was used very successfully on leaky wheel bearing felts which leaked onto thee brake shoes of an older car.
--
Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"

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On Tue, 15 Jul 2008 13:17:13 +0100, Charles Ping

How much crankcase pressure is there from the engine?
A sealed bearing will be fine.
Peter -- Peter A Forbes Prepair Ltd, Rushden, UK snipped-for-privacy@prepair.co.uk http://www.prepair.co.uk http://www.prepair.eu
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On Tue, 15 Jul 2008 13:34:46 +0100, Peter A Forbes

almost none - it vents all over the place (lately all over the magneto)
Charles
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Charles,
A sealed bearing is only as good as the seal which is fixed but the inner must still rotate therefore there must be a gap. The seal is generally to retain the grease and keep out the dirt.
Martin P
wrote:

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On Tue, 15 Jul 2008 14:12:11 +0100, "campingstoveman"

a Z (shielded) bearing will have a gap, but an RS (Rubber seal) bearing won't have a gap. A 2RS bearing is probably indicated in this application,
Mark Rand RTFM
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Mark, Agreed but oil pressure will break through over time.
Martin P
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wrote:

As written previously, they are only to keep dirt out and grease in. I only know of the black rubber oil/grease sealing rings.for this purpose. Dirk
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