Norton ES2 1939 oil in timing case

Your problem seems like it is due to pressure relief valve passing far too much oil.  Attached extract from the 1950's manual by F Neill describes how it should work.

Any oil in the magneto chain area is passing the inlet cam bush. Is the bush badly worn, incorrect or wrongly fitted ?

The exhaust cam bush which is entirely within the timing chest has oil grooves along the whole length of the bush. On the inlet bush which is only intended to pass oil mist onto the chain, the grooves stop about halfway. If the bushes have been swapped then far too much oil will pass. Otherwise, it's likely to be a wear problem.

hello,

just found one of my blurred photos showing an inlet bush.

barry

 Hi Dirk,

   All the above answers are relevant, but even if the inlet cam bush is very worn the oil should not leak so quickly, unless you have the wrong bush fitted. When you fitted the new oil pump did you check the that fibre washer that fits between the pump and the timing cover was the correct thickness ? This should hold the cover away, when you hold it by hand, by a half millimetre so when you tighten the screws the washer is slightly crushed to form an oil-tight seal. If the fibre washer is missing or not thick enougth the oil will spew out into the chest and not to the big-end bearing. You should also check the oil is returning to the tank O.K. which should be a dribble at tick-over. Another possibility could be the spring in the brass big-end feed quill that runs in the end of the main-shaft which could be missing or broken and allowing oil to leak into the chest.

   You should remove the timing cover and check the washer, the pressure release valve, the crank-shaft quill and, if possible, replace the cam-wheel bushes. Also check the engine breather behind the engine sprocket is clear and the ball is free to move so you do not get excessive crankcase pressure.