Well ive finally got round to changing my cam in car as it was worn on number 4 lobe and had destroyed a tappet which i replaced and worked fine for a while.but ive taken all lifters,cam and rockers off and it looks like the rockers have been rubbing on the head and worn bits off it away now this aint right its got the little black spacer plates fitted on the bit you slide rocker over before putting nut on. but why would it do this is it because the cam is worn??????? any ideas as dont want put back together and it do more damage

few pics of it but not to clear..


Where its yellow is where its worn

cheers
jon