Chuck Dunlap wrote:

I just took apart my 13b after replacing it with my spare. I removed it
because it was low on power and blowing oil out the breather tube.  I found
the front rotor overheated. The front face was the worst, the side seals
were partially disintegrated and totally seized in their slots. The oil seal
O-rings were completely gone on that side, only part of an O-ring remained
on the rear face.

The cause was a piece of silicone sealant stuck in the E-shaft oiling jet,
blocking oil cooling to that rotor. I had modified the jets by removing the
ball and spring and installing a smaller Weber jet. This was a bad idea, I
think the spring would have acted as a filter and kept the debris out. The
offending debris came from too much sealant used for the stock oil filter
bypass plate. Second lesson learned: Don't use silicone sealer anyplace
after the oil filter. Or at least use it very sparingly.

Paul Lamar responded:

Amazing you flew that airplane all those years with this problem.

Eh?  How do we know when the silicone sealant debris obstructed the oiling
jet?  I'm not saying that it happened only 15 Tach minutes ago, but how do we
(or at least Paul) know when it happened?

Russell Kent

Chuck has been noticing something wrong for years. In fact I probably
got a ride in the airplane back when it was suffering from this
problem. I assume the silicon was used when the engine was assembled
for the first time. Jerry Hey got a ride not too long ago when we did some
airflow measurements on Chucks cooling system so the performance
was not all that bad. I drove my Cosmo with shot oil O-rings
for about ten years.

Paul Lamar
 
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