If your running a lot of spring pressure the extra oil from grooving the cam will help cool the valve springs a bunch. Years ago Car Craft or Hot Rod did a article on Air Flow Research using a 50 HP electric motor to spin a SB Chevy test mule motor over with no spark plugs and then with no rods or pistons with the crank oil holes block out.(This was when they where under exclusive contract with Jr Johnson Racing)They ended up determing that 80% of the oil temp was generated by the valve springs I groove all of my cams now, hydraulic,solid, hydraulic roller or solid roller, BB, SB or Hemi I do use a crankshaft scraper also to help aid oil control and controling the slinging onto and off of the rotating crankshaft