make sure absolutely no grinding paste gets onto the stems or else you are enlarging the hole which is a BAD thing to do. 5 mins per valve with fine paste only is the rule of thumb - if you use the coarse stuff you can put ridges in that are really hard to get out. Then to test degrease and put 4 pencil marks 90 deg apart radially. A quick dry lap then see how the pencil mark has spread. It should be an even spread and not peaky
what exactly were you doing andy?
there was a mention of porting/polishing but funds wouldnt allow that.
so really learning tbh, enjoyed it, but eck hard work
I would have had it off you if you hadn't messed it up