How much ZDDP gets used up?

[edhackett]

I don't think you can use UOA to determine zinc usage. The ZZDP molecules are broken down when reacting to heat and pressure, but the zinc doesn't go away. The figures 440Magunum shows for VOA/UOA are withing the normal accuracy of cheap UOAs.

Ed

 

[440Magnum]

Originally Posted By: edhackett
I don't think you can use UOA to determine zinc usage. The ZZDP molecules are broken down when reacting to heat and pressure, but the zinc doesn't go away. The figures 440Magunum shows for VOA/UOA are withing the normal accuracy of cheap UOAs.

Ed


Good point. This is where I say "duh"

What is the end product of the reaction when ZDDP breaks down under pressure?

 

[440Magnum]

Originally Posted By: OVERK1LL

Just another reason I am thankful to be running a billet roller in my performance junk.


There are lots of reasons to be thankful for rollers

Next build I do will probably be a roller. I've always been a little nervous about retrofitting rollers to old blocks- I was always suspicious of the mechanical spaghetti code (the crosslink bars between lifter pairs) that they use to keep the rollers aligned in the bores- at least for high-mileage street use. I had visions of rollers getting more and more sideways as the link wears, but apparently its not a problem.

 

[OVERKILL]

Originally Posted By: 440Magnum
Originally Posted By: OVERK1LL

Just another reason I am thankful to be running a billet roller in my performance junk.


There are lots of reasons to be thankful for rollers

Next build I do will probably be a roller. I've always been a little nervous about retrofitting rollers to old blocks- I was always suspicious of the mechanical spaghetti code (the crosslink bars between lifter pairs) that they use to keep the rollers aligned in the bores- at least for high-mileage street use. I had visions of rollers getting more and more sideways as the link wears, but apparently its not a problem.



Nope, its not. Apparently they work VERY well according to my cam grinder which uses them in everything.

 

[[RT] ProjUltraZ]

i've read articles that say ZDDP volatilizes and can poison catalytics conv, the main reason for the reduced zn/phos in SM oils

that's probably where the losses are coming from. higher heat = higher volat as in racing

UOAs have a margin of error but many look like they have reduced zinc and phos

 

[bountyh]

Originally Posted By: Blink7
Well I do think its an issue, and a real one. I just had my cam ruined with these newer oils. And to top it off, the oils I have ALWAYS used in the motor have been synthetic 5w-40.

Originally Posted By: mechtech2

But according to an oil engineer on a car talk show I was watching, the whole deal is not a real issue.


There is another aspect of the Zinc story nobody addresses:

I read many horror stories of cams in newly rebuilt high performance engines being scored and ruined running the low (or NO) zinc oils. That's a catastrophic failure which obviously screams "HERE I AM!". One could try to write that off as "strong spring" problem. But, does that mean that low zinc oil is as good?

What about simply increasing wear rates on specific engine surfaces. The zinc builds a barrier to reduce wear on metal-to-metal contact. Both my car (and my motorcycle) sometimes go a week or more without being run..... no job, that's another story.

Anyway, when the oil has drained down and you fire up cold, zinc would be essential to reduce wear until the oil gets up and establishes proper film strength. So, in brutal cases wher you have a lot of cold (dry) starts, seems like zinc would reduce wear. I'm not saying the new oils would cause a catstrophic failure, but I believe they certainly would not protect as well as zinc barrier oils would.

 

[bountyh]

Originally Posted By: [RT
ProjUltraZ] i've read articles that say ZDDP volatilizes and can poison catalytics conv, the main reason for the reduced zn/phos in SM oils

that's probably where the losses are coming from. higher heat = higher volat as in racing

UOAs have a margin of error but many look like they have reduced zinc and phos


I read the EPA is forcing the Zinc and phos out so the cat converters will last 150,000 miles. More important, they don't want the gradual degradation of the cat over time that allows increasing emissions but still doesn't fail. I think it's a load of baloney and I think they don't care what it does to engine life as long as it doesn't increase emissions when it dies.

 

[BuickGN]

Originally Posted By: bountyh
Originally Posted By: [RT
ProjUltraZ] i've read articles that say ZDDP volatilizes and can poison catalytics conv, the main reason for the reduced zn/phos in SM oils

that's probably where the losses are coming from. higher heat = higher volat as in racing

UOAs have a margin of error but many look like they have reduced zinc and phos



I read the EPA is forcing the Zinc and phos out so the cat converters will last 150,000 miles. More important, they don't want the gradual degradation of the cat over time that allows increasing emissions but still doesn't fail. I think it's a load of baloney and I think they don't care what it does to engine life as long as it doesn't increase emissions when it dies.


I think my car is going to be a good example whether it's good or bad. I switched it to a high ZDDP oil when it was new and have run it for 77,000 miles. If and when I have a convertor failure, assuming no obvious problems like a misfire, I'll have a pretty good idea how much of a problem this is or isn't.

 

[Gary Allan]

Quote:
I read the EPA is forcing the Zinc and phos out so the cat converters will last 150,000 miles.


That's probably a future goal; getting OEM certs for 150k. It won't stop you from putting even more zinc and phos through your engine by changing it out real early like many do here. You'll still volatilize some percentage of it and poison your cat (NOT) in smaller continual doses of the poison instead of larger doses.

 

[Peted]

Originally Posted By: bountyh
I think it's a load of baloney and I think they don't care what it does to engine life as long as it doesn't increase emissions when it dies.


They could care less.