One of our HQ Techline members, Battersby, was kind enough to provide these pics while "pre-charging" his lifters. Thanks. Here's a few more facts about lifters from Doug:
There is an expression in the lifter industry. ‘Hydraulic lifters are the best oil filters on the market’. In simple terms, that means dirt can get in a lifter through the oil feed, but can’t get back out. A lifter will capture dirt particles as small as 1 micron. A top quality fine oil filter only captures dirt 5 microns or larger. So clean engine assembly is a must.Over 90% of failed lifters are a result of dirty oil. Wear as fine as 50 millionths of an inch (that is 1/2 of 1/10th of ONE thousanth of an inch can make a lifter fail. And it takes only seconds.Clean engine assembly, clean oil and priming of the lifters before initial start up is essential.