Is zinc used as anything other than an anti-wear additive

[OffOrWFO]

Is zinc only used as an anti-wear additive or does it have another use in oils? So basically, is all the zinc that shows up in a VOA anti-wear additive?
I have noticed that the amount of zinc in most oils have been reduced and will probably go down even more when the new SM oils come out. What is the reason for the reduction and what is replacing the zinc?
I have been told that older non roller lifters and cams don't do well with less zinc. Anybody heard of or experienced this?

 

[Motorbike]

Zinc is also a good anti-oxident .

Your question about cams is answered with the actual type cam lobe and spring pressure . A combination of film strength of the oil and other anti-wear additives come into play there .

Others might have a better answer but the dang car makers were concerned about the money it would cost them to warranty the catalyst system beyond 80k miles and I guess it was the EPA pushing for that so reduced phos was thought to be the answer for longer lasting catalytic converters . There is a bit more to it than just that .

I am certainly glad some don't have any more power than they do because it seems to me some of the entinty's

cannot see the forest because of the trees .

They might should leave the phos cap at 800 for all of time left on earth and reduce the additives that cause deposits in the combustion chamber for a cleaner burn over the life of the car and tighten up the minimum NOACK more to include forcing better quality control when machining the valve guide chimney for the positive type valve seals . More than one engine series out there suffers from this problem that leads to premature seal failure . Another alternative might have been to force the auto makers replace the cats at 100k miles as part of the purchase if they cannot cowboy up and index the center of the valve guide to the OD of the chimney correctly before whipping those heads through the assembly process . I was always of the thought if I were to do a job to do it right the first time . It's senseless some of these motors are shoved out this way . Some are prone to failure at around 50k miles and smoke on start up for another 150k . Most don't see it because the cat takes care of it when newer . Pull the cat off certain GM and Ford engines with fairly low miles and watch what happens . The biotches smoke

Cats are relatively cheap and the metal is recyclable . The car makers who cannot get an engine to pass w/o using 40 precats with 20 actual cats behind them might should develop better engines .

[ August 19, 2004, 07:15 AM: Message edited by: Motorbike ]

 

[Ken2]

Not zinc.

The antiwear and antioxidant is zinc dialkyldithiophosphate, or a related compound, not just zinc. The phosphate part shortens the life of the cat con, so it is being reduced. There are other compounds that work as well or better but may cost more.


Ken

 

[MolaKule]

There other zinc compounds for automotive use.

One is called zinc diakyldithiocarbamte and is used as an metal deactivator and anti-oxidant. It is especially useful at deactivating copper metal interactions; as in keeping copper alloy components from becoming stained or from being attacked by EP additives in gear lubes.

 

[mechtech]

Motorbike - Hmmm... That's a good point to consider [a working cat conv reducing the smoke that would be evident otherwise].
Those rascals!

 

[Pablo]

Gee, you may be on to something, Motorbike

!

Seriously and the only thing I will add - there really isn't anything 100% scientific about 1000 PPM P or 800 PPM P....those numbers are not magic....

 

[OffOrWFO]

Motorbike-I don't think a cat will do anything to reduce smoke or emissions until it heats up. I've owned one car that started burning oil at 70K and the cat got so hot it melted things close to it and then died shortly after that.
The reduction in AW additives is partly because it poisons cats and the EPA requires new auto emission systems to last 150k now. But is the reduction of zinc due to this or because the EPA thinks it's bad for the environment?

quote:

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there really isn't anything 100% scientific about 1000 PPM P or 800 PPM P....those numbers are not magic....

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Pablo- could you spell this out for me? Do you mean that 1000ppm doesn't necessarily equate 0.001% of the oil?

 

[Pablo]

Actually what I meant is:

1000 ppm or 800 is not some "magic" number that automatically kills the cat if exceeded.....a good oil with 1800 ppm (or 801 or 1299 ppm) of P could be used for 30 years and the cat will be fine.

PS Your decimal place is off by a bit....