Ray H, the reference to imported valve lifters is NOT referring to the OEM Import Lifters, but to the multitude of "off shore" or "Asian sourced" valve lifters that are pretty much everywhere in the automotive replacement parts supply chains. These lifters do not carry USA OEM name brands as such, but are usually available from auto supply and machine shop sources. Just as with other aftermarket parts from those regions, there are good ones and less-good ones -- which you don't know when you buy them as "they all look the same" outside of the materials used in their packaging.
If the parts have an OEM manufacturer or (OEM or USA name brand) aftermarket vendor's name on the packaging, those parts are made to the seller's specific specifications and quality/durability standards. Otherwise, items sourced from those regions can vary from one name on the box to another name on the box.
It's the inconsistent quality issue that has prompted some camshaft manufactuers to make the statements they have, which some has interpreted to be "bashing" in nature. From the perspective of the camshaft manufacturers, THEY have to protect their good name and do not desire it to be downgraded if a customer decides to buy some auto supply lifters (of undertermined quality) rather than their more expensive "matching" lifters with the camshaft. I suspect the cam manufacturers have done enough R&D with their camshafts and replacement lifters to know what really works and what does not.
On the subject of the GM Engine Oil Supplement, which many cam manufactuers recommend, possibly in conjunction with their own "moly" lube paste . . . there used to be TWO forms of GM EOS. One is the "small bottle" supplement that is currently available (highly viscous) and the other one is the "one quart of oil replacement" that was formerly available.
Both tended to have the same dialogue on the container, but were used in different manners. GM now has a "Camshaft and Lifter Prelube", which seems to mimick what the aftermarket camshaft makers have offered for years (at least in size and orientation of the packaging).
I went into PepBoys a while back and read oil bottles for notations of "ZDDP". Some specific Valvoline and Castrol products have these notations on the back of the container. Certain Valvoline VR1 "off road use" racing oils and motorcycle oils, plus the Castrol Tection 15W40 oils, but not on the GTX Diesel 15W40 bottles (obviously for lighter duty diesels). A mixed bag of sorts, but still "options". Considering that ZDDP is what it is, I suspect the marketing operatives will note its presence in the product (seizing the moment, so to speak) for the more informed consumer.
To me, the really big question would be what is replacing the small amount of zinc that has been removed? Some manufacturer's website charts list the % of zinc and such in them. Surely, the oil companies know that these products will be or can be used in flat tappet engines rather than exclusively in roller cam motors?
Just some thoughts,
CBODY67
