How is it personal insults when I'm pointing out that you're being argumentative, especially when you're being so? How many references have you posted so far to counter my claims? I've answered many of your questions and your response every time has been to come up with a new question.
I told you to look at the second page (copyright page) of the book but you didn't. It was published by SAE in September 2004, 9 years 4 months ago. It's the second edition:
You dismissed a nine-year-old authoritative SAE book on engine oil saying that it was outdated.
Sure, the wear can be measured. It's measured by the Sequence IVA (ASTM D6891) test. However, good luck finding any results of the test disclosed. The only results disclosed I am aware of were during the Mobil 1 - Valvoline SynPower - Castrol Edge war. The maximum acceptable wear limit is 90 microns and the SM version of Mobil 1 had showed 180 microns of wear, according to private tests:
How is HDEO more affordable than PCMO? The original question in this thread was whether a flat-tappet engine could benefit from higher levels of ZDDP in CJ-4 oils. The answer, according to the references I posted, one of them being authoritative, is probably not, the reason having got to do the with type of ZDDP (primary vs. secondary), amount of dispersants and detergents, and optimization of the additive packages for gasoline or diesel applications. Would a CJ-4 be adequate for flat tappets? Probably, yes, and I've never said no. However, being adequate wasn't the original question. The original question asked whether a CJ-4 oil was a better choice than an SN/GF-5 oil. The answer, according to this reference, is no, and everything it says makes perfect sense. In fact, chances are that an SN/GF-5 oil provides better wear protection for flat tappets than a CJ-4 oil. Extra ZDDP in CJ-4 oils is to make up for wear induced by extra dispersants and detergents in CJ-4 oils, not to provide additional wear protection surpassing wear protection in gasoline engines. In fact, gasoline engines are more wear-prone and they demand more wear protection than diesel engines.
You can keep being argumentative and claim that we still don't know for sure because we have never seen the Sequence IVA results. Yes, you can never be sure which oil provides less wear in Sequence IVA or in real-life driving. However, we can still give a general answer to the question asked here originally.
After being told about the different types of ZDDP (primary, secondary, or a certain mix of a certain ratio of the two) used in diesel vs. gasoline oil and wear-inducing dispersants and detergents in diesel oil, if someone still thinks that 1000 ppm P of ZDDP in a CJ-4 oil will offer more wear protection for his flat tappets than 800 ppm P of ZDDP in an SN/GF-5 oil, well...
Anyway, Jim, I have no hard feelings here -- I was just frustrated by your seemingly argumentative responses.