Topic: lack of zinc in engine oil....

[BobbyR]

Hmmmmmmm, this is very good data. I may get one done myself. I did one on a Pontiac I had and I won a claim with GM. Good to know empirical data on the health of your engine.

[crazypj]

Pretty weird in my opinion.
 Rotella has higher levels of zinc than 'normal' car oil but its still not too high.
 high iron content is easy to explain, along with some of the other materials- transmission wear, cam chain & sprockets,
 Phosphor bronze bushing, steel on steel, clutch friction material, etc.
 I guess it would mean more if compared to fresh Rotella?

PJ

[Deltarider]

Why this emphasis on zinc in oil?
I've always understood that zinc and copper are not particular friends.

[crazypj]

Zinc is a high pressure lubricant for steel ( cam&cam followers, transmission gears)
 copper and zinc like each other a lot.
http://en.wikipedia.org/wiki/Brass
PJ

[BobbyR]

The idea behind the oil analysis is like a blood test you get from the Doctor. Many parts of an engine are plated to a known thickness with known metals. When the metal below the plating makes it self known, they infer that the parts have worn. I am not sure if having clutch material mixed in the oil skews the readings. I assume the company do the analysis has data on that. I know large truck fleets and railroads rely on them to decide at what point an engine need rebuilding. Rather than relay on hours run. Why I find interesting is they recommend he try a non synthetic and retest. I am not sure what they mean by that, I just find it an interesting comment.

[Inigo Montoya]

I wondered about that comment as well. It implies that they think conventional oil would be better but maybe it is solely for benchmarks.

[crazypj]

You send a sample of new oil and pay to have that analysed, that way you have a baseline.
They have already analysed many 'stock' oils.
 The only synthetic they specifically mentioned when I got kit was Mobil 1
 Rotella has been modified a few times in last 12~18months

PJ

[Duke McDukiedook]

Yeah, that is what I was thinking when super pasty submitted his used oil.
Would have to send fresh oil "control" to compare to.

[HondaMan]

roller top end for the vintage cb's, now that would be cool

They were available from about 1978 to around 1986. There was just one manufacturer, and the kits showed up in various aftermarket shops. They were harder to assemble than a Rubik's cube, with all those tiny needle bearings... 
The only history I had with them was on drag bikes: they made a noticeable throttle response difference and probably increased the top end RPM. But, the needles on the rocker shafts were too small, and the top end needed more oil to keep them alive in regular street use, which would mean lots of engine mods for a daily-rider bike.

And lots of zinc in the oil to make them last.