crane cam

Yes, all cams slow down a bit on closeing the valves. Opening can be as quick as you can get it. The newer engines should last longer than older ones or sooooomebody didn't learn there lessons. LOL

Key to many mile engines is fresh fluid and cool running.
Key to long valve train life is another ball of wax. The roller cams can cover 2 bases at once by compare to the older cams.

Ya gotta love the advancements made in these areas. Hollowed cams, better metals for componets, rollerized, it's great. Makes our old iron better and last longer.