It would seem like he talked to a mechanic at the ECI tent at Osh.

Oil leaks are a long subject.
The engines were never designed to be totally leak proof but they can be made 
relatively leak proof.
Eliminating the leaking of oil and going to the subject of blowby, the blowby 
oil would be on the belly and not so much in the "engine room" or running along 
the side of the plane.

As for blowby:
Most mechanics do a simple compression check to get some numbers to write in 
the log book. However, if you have a blowby problem, you would very likely have 
low compression on one or more cylinders.
If you do have low compression on a cylinder, while holding the prop at the top 
of the compression cycle with 80 PSI going in, ( you need someone strong to do 
this for you), while you check where the air is escaping. The air can escape 
three ways:

A) Past the rings, in which case you can stick one end of a plastic tube in the 
breather tube and the other end in your good ear and hear the air escaping into 
the crankcase. A honing and a new set of rings may fix this.

B) Past the exhaust valve, in which case you stick the end of the tube into the 
exhaust pipe, ( no, the other end of the tube ) and hear the air escaping into 
the exhaust manifold.

C) Past the intake valve, now you stick the end of the tube up the carburator ( 
yes, that end, you have got the idea now.) and hear the air escaping into the 
intake manifold.

This gives you an idea of what to look for in a cylinder rebuild.
I sent the same cylinder several times to get the exhaust valve fixed and they 
kept doing a very poor job. I spent more on UPS and repairs than a new cylinder 
costs. After a while I pondered that these were after all the original 1946 
cylinders, so I sprang for four new ones and never had another problem.
the new cylinders have newer metallurgy, are made for 100LL fuels, the intake 
valve seats are steel, not brass, valves and guide metallurgy are much 
improved, rings and cylinder walls are much more durable. New springs...

We have come a long way in metallurgy over the last 65 years.


Alan Fairclough
N87333
N94694

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