Right, update time...
Head off, not to bad a job... One piston looks like it has been steam cleaned so suspect water getting in the cylinder. Therefore theory correct about the head gasket. Head bolts didn't seem tight. Does anyone know what they should be torqued up to?
Given lobe had worn off, also removed sump to have a look at crank and shells... Not a pretty sight on cylinder one. Shells in very bad state (starting to break up bad). Interestingly shells seem to be soft metal only. What happened to the steel backed ones?
Anyway, it's going to need at least shells...
Think I found the reason the lobe had worn, the cap adjacent to the worn lobe was completely slack, one of the cap bolts was stripped. Whoever rebuilt the engine (I know who, but am not prepared to say the Alfa specialist by name) stripped the thread and just left it... Anyway, that will need sorting.
Whoever did the rebuild seems to have an aversion to tightening bolts. All sump bolts were loose. One that goes through from the gearbox was finger tight!
Anyway, I digress. Anthing i need to look out for before I put it all back together.