I see a lot of posts about breaking in cams, cams going flat etc...how would you tell if a lobe did round off?? never had one go , so I wouldn't know what to look for...TIA

you will sometimes hear a popping through the carb

sometimes you will get a miss
and if you pull the valve covers you will see the rocker over the rounded lobe does not move up and down as much as the rest if it does at all

I found out the reason (read it somewhere) why you run it for 20 minutes or so on inatail start up at 2 grand to break the cam in. Can anybody explain whats going on in those 20 minutes with the cam?