superscott said:
If a lifter gets stuck near the rear of the block; will that block oil flow to the other lifters down stream?
Also, what is it that happens with low oil to the lifters? I understand that they don't get the pressure to pump'em up, but do they compress and plunger gets stuck down? if so, can the lifter be fixed, or is it scrap at that point?
Because the lifter has a machined band around its circumference, oil will still be supplied downstream from a stuck lifter.
The lifters will stay pumped up w/as little as 5 psi- but obviously that wouldn't be enough to allow the engine to run normally at much above an idle, the lifters would quickly bottom out w/very low oil pressure, I would think. Nevermind the bearing damage that could result.
If a lifter bottoms out, as long as it's not damaged somehow, it should pump back up on its own accord given sufficient oil pressure. If it doesn't, the lifter may need to be removed and disassembled for inspection and cleaning.
To answer one of your original questions, if the rear cam bearing is installed incorrectly, this can affect the oil flow. If you look closely at the photo below, you can see how the rear cam bearing isn't installed deep enough, only 1/2 of the bearing oil hole is aligned w/the annular groove. If the bearing were a bit further forward the hole would be totally occluded.
The same thing can happen if the bearing is too deep.
If a gallery plug is leaking or missing, that can lower oil pressure also. If the oil pump is badly worn, damaged or has a sticky pressure relief, or if the oil filter is defective or the oil filter mount by-pass is defective- all these can cause oil pressure woes.
What brand of filter are you using? If it's a Fram, you might try a different brand- like NAPA or Mobil 1, etc. Some filters are just like Fram but I don't know which ones they are, you can google oil filters and see what's up for yourself.
How was the oil pickup/screen installed?