Zinc & Phosphorus -- Brad Penn Oil

[elmariachi]

Originally Posted by patrickt

But I will tell you from my experience in discussing these matters with other engine nuts who send their oil in for analysis, the results of these tests are notoriously wrong. Identical samples sometimes come back with vastly different numbers. Mostly, I like to see a reasonable zinc & phos number, and no water or antifreeze in the oil. Other than that, I take everything it says with a grain of salt.

Just curious, how you can say the results are wrong, but then rely on the zinc/phosphorus numbers and the absence of coolant? FWIW, I have used Blackstone for analysis of my expedition Toyota Land Cruisers (I've had 11 of them in 20 years) and found their data to be extremely consistent and reliable. Like you, I have relied it mostly for detecting water/coolant, as these trucks are prone to HG failure after 150k miles.

[patrickt]

Originally Posted by elmariachi

Just curious, how you can say the results are wrong, but then rely on the zinc/phosphorus numbers and the absence of coolant?

That's a fair question! For the zinc & phos numbers I only look for a range, as the BP people swear to me that it really does have 1200ppm. If the numbers had come back anywhere from 1000 to 1900, that would be fine. If there was any moisture in the oil, I'd send them another sample to double check it (since it's still sitting in plastic containers in the garage). Same if a metal came back really high. The accuracy reports come from the forums on BITOG, Pelican, LN Engineering, and what not where VOAs of the same oil come back with significantly different values or where guys send the same sample to two different labs for comparison. I've only sent in a handful of samples myself, and honestly some of the accuracy problems could be the result of the user's method of oil collection. But, I suppose they're just like blood tests -- double check them before you sign up for the operation.

[elmariachi]

Originally Posted by patrickt

and honestly some of the accuracy problems could be the result of the user's method of oil collection. But, I suppose they're just like blood tests -- double check them before you sign up for the operation.

Hahaha, good analogy. And clearly the results will be different if you collect oil as it drains out of the pan versus pouring some into the Blackstone canister after its been sitting in an open drain pan on your garage floor for a week.

I've got about 3 hours total runtime on this engine, I think I am going to unscrew the filter and pour off a sample so I can compare it when I do my first oil change. Probably a waste of $$, but what the hell....

[patrickt]

Originally Posted by elmariachi

I've got about 3 hours total runtime on this engine, I think I am going to unscrew the filter and pour off a sample so I can compare it when I do my first oil change. Probably a waste of $$, but what the hell....

Jeez, an engine with only 3 hours on it, I believe, will have a veritable shi_load of metal in the oil, as compared to what you'll see after it has really broken itself in. The report is likely to look pretty scary. Uhh, if you were so inclined you might want to put on the sample "Engine has 10,000 miles on it, this oil sample has 1,000 miles on it" and see what their diagnosis is.