I suspect that the top hats are blocked Derek, all mine valve chest cover joint are covered in oil. Leaving the top hats out isn't a good idea the vacant holes seem to have a magnetic attraction for valve collets.

It's not blocked Top Hats. I have replaced the block but using the same top hats I checked them and were clean so have used them again. The mystery goes on.
Thanks for your help chaps

Location: Oakley , hants

Thinking back to my first Ruby, when the piston rings broke up (due to rusty ridges following a 10 year lay up in a damp shed by the P.O.) she blew smoke rings out by the starting handle. I wish I had thought to video them!

In your case Derek I would think it is possible that steam filling the tappet chest could have stopped the flow of air through the top hats and the oil mist that would have lubricated the valves may have exited your engine via the nose too.

I have not tried steam cleaners... but...

I thought I had a lot of oil leaking from my tappet chest recently, then remembered something about the square headed bolt into the front cam bush... oh joy

Location: not in the garage :(

Thanks Nick,
You may well be right. Have now done four miles on the new engine but am loathed to disturb the valve chest cover to have a look.

Location: Oakley , hants

I strongly suspect that oil mist will not get into the valve chest if there are no ventilation holes on the cover. If there is no outlet then the valve chest will just be at the same pressure as the crankcase so there will be no incentive for it to flow into the valves.
The same thing happens I believe with the rear main bearing on 1-1/8" cranks. There is no outlet on the gearbox side of the bearing so no incentive for oil to find its way through the bearing.
The inside of a splash lubricated engine must be a very oily place indeed. The oil from the jets hitting the fast moving crank will create a great deal of oil mist. The main reason why the engines leak oil at the slightest excuse.

Location: not in the garage :(

Good idea

Location: Oakley , hants