Thanks for your input Neil.
I have already investigated the ‘splasher option’ but there is only about 2mm clearance from bigends to crankcase base! I decided this wasn’t going to happen.
I have made a new breather which is now much taller with a larger bore and a mushroom shaped top, under the rim of the top I have 3 small bore holes at 120 degrees drilled up at 40 degrees to meet the bore.
I have also fitted ‘O’ ring seals to the main bearings.
This afternoon I have had steam up.
With 15cc of steam oil in the sump this gives about 3mm dip of the bigends, and I am pleased to report that it is now oil tight!
It was running for about an hour and even when loaded and working hard (by me gripping the flywheel!) there was only slight wisps of steam from the breather.
Drainng the oil while hot immediately after running I found the oil was well churned up and moisture present, in fact I would consider that the level would rise with running due to moisture?
Anyway, bathtime next! complete with ‘oil slick’ round the bath!