Rocker arms/ lifter questions

[Blzr6.2'83]

I pulled my valve covers to see if I had bad lifters because I heard knocking. I ran the engine and noticed it took a while for all of the rocker arms to have oil come out of them. Some started puting out oil quickly where it took a others a few minutes with some slight reving to get oil out of them. Is this a sign of bad lifters? And if so, do they have solid lifters that would not go bad like the hydraulic ones or doese it need hydraulic lifters?
There was also quite a bit of blow by inside the heads and crank case. I have checked it by watching how much came out of the oil fill tube and there was not much, but it looked like alot in the heads and down in the crank case. Is this normal?

[john8662]

All 6.2's and 6.5's feature Hydraulic Roller lifters, so they're the basic hydraulic lifters but with the added wheel on the bottom that rolls on the cam (less resistance and wear).

Anyways, to diagnose the lifters you'll want to find a way to rotate the engine over by hand. Since you have an '83 you don't have to remove your crank pulley to get access to the harmonic balancer bolt. Get the appropriate socket and 1/2" wrench drive and rotate the engine over with that bolt. Don't worry about loosening it, it's torqued to 200ft. lbs. so no worry there. Now, go ahead and remove all your glow plugs, that way cranking over the engine will be MUCH easier (as it will be releasing it's compression).

Once you've done the previously mentioned tasks, you are ready to search for a bleading down or flat lifter. You will now rotate the engine over until you see #1's valves open and close. I watch the first valve of the pair open and close then immediatly following the second valve will open and close, as soon as the 2nd valve's rocker returns back upward fully (valve closed) you will stop rotating the engine. Then take and grab the rocker and push it down on the pushrod side. You shouldn't be able to push the rocker down into the lifter below via the pushrod, if the lifter is pumped up.

A flat lifter will allow you to rotate the engine over and at a point when the valves are supposed to be closed, the pushrod will be loose. A bleeding down lifter you will be able to push down on the rocker and it will be springy, the pushrod will also be loose.

While you're in there you will also be looking for bent pushrods, and to help you find a bad lifter, while you're rotating the enigne over you'll be able to hear a click at one point, and that usually finds a bled down lifter.