Originally Posted by Docpsycho
MouseFink- In my case, half of my new lifters came "collapsed", the other half is "pumped up", If they were all the same, I would not be concerned with them.
You should never pump lifters full of oil before installation. If the lifters are full of oil, they will not allow the valves to seat. If you try to start the engine, the valves can then hit the pistons, bend some valves and push rods.
Set the pre-load with the lifters dry, and then either crank the engine with the starter or turn the crank three or four revolutions by hand while pre-lubing the engine with a variable speed drill motor. If you have set the pre-load using the correct procedure, there will not be a need for a re-adjustment after the engine is running.
New lifters are lightly coated with a preservative inside and out. Since the clearance between the plunger and lifter body is less than .0002", some of the plungers may be stuck after being in storage. In order to free up the lifters, rinse and cycle the lifters with a push rod in mineral spirits and let dry.. As you install each lifter, lightly coat the lifter bore and the lifter will motor oil. Adjust the pre-load using your favorite method. Crank the engine over a few times with the starter then let the running engine fill the lifters.
Standard GM lifters set at .060" to .080"pre-load (1-1/2 turn to 2 turns) which is 1/2 plunger travel.
The net lash pre-load adjustment cannot be set with oil in the lifters. Those lifters set at .120" pre-load (21 lb. torque) with the cam lobes in any position..