"Lifters bleed down slightly w
"Lifters bleed down slightly when there is no oil pressure and the valve is open with the spring putting pressure on the lifter. Best way to make sure valve is fully closed and you are not on the ramp is to adjust valve directly opposite in firing order from valve that is open. Adjust number one intake valve when you see number six is open, etc. I always adjust my valves before I put the intake manifold on. If you have to adjust valves on a hydraulic lifter engine after it has been run you have other problems. Many engines like 302 Ford have no adjustment, you simply bolt the rocker arms down. If you have been tightening them down you may have to back them all off a couple of turns, spin the engine long enough to get oil pressure, zero lash all the valves opposite of open valves working your way through all, then add your half to one turn preload. Allow them to sit for ten minutes or so to bleed down then start the engine."