Zinc Additives, Cam Shaft Or Rocker Wear, And Mileage - A Poll

[Zed Head]

A note, or warning, for anyone reading through this who has a later year, or CA, car - these ZDDP containing oils will probably degrade your catalytic converter.  You can't use them.  So the focus for those people would be on the best wear resistance, without ZDDP. 

 

 

So far, the things that stand out to me, from what I've read, are that zinc,or ZDDP, level alone will not predict wear protection (it's the complete oil and additive package).  ZDDP is most important during break-in, like within the first few seconds of contact and pressure and the first hour or two of wear-in.  Once the galling starts, it just keeps going.  ZDDP is more important for engines that have high pressure areas, like flat tappet cams with high performance cams and springs.  Cam and rocker materials probably play a factor too, they need to work together.

 

And it's a complicated subject that's hard to understand, even for the professional  engineer.  Some of the most interesting work out there is by engineers who were trying to do a study on another issue, but their mule engines kept wiping cam lobes.  I've collected several papers and may add them later.  They're long and boring though.

 

Also, the most reliable recommendations, after break-in anyway, will probably be from people who run (ran) fleets of cars, like taxi companies.  High mileage, abusive conditions, and the bad oils are probably weeded out pretty quickly.  But it would have to be from before the shift to roller-rockers.  I'm still looking for that kind of information.  

 

In today's world, the marketing guys just have too much influence,  I can't believe anybody's ad copy.

[Zed Head]

Pennziol GT Performance Racing Oil 25W-50.  Highest zinc of any available engine oil at 1,968 PPM.  Our oil analysis reports zinc levels over 2,100 PPM and its all we use in air cooled Porsche engines.

Aren't the racing oils designed for low miles?  How often do the Porsche guys change their oil?

 

Pretty cheap at Amazon though, with free shipping. http://www.amazon.com/Pennzoil-3623-12PK-Performance-25W-50-Racing/dp/B00B2IO58W

[Jeff G 78]

A note, or warning, for anyone reading through this who has a later year, or CA, car - these ZDDP containing oils will probably degrade your catalytic converter.  You can't use them.  So the focus for those people would be on the best wear resistance, without ZDDP. 

Not doubting you, but unless the car is burning oil, there should be very little ZDDP getting to the cat.  I am surprised the cats are that sensitive.

[Zed Head]

Apparently the phosphorous ash coats the catalyst particles, rendering them ineffective.  It doesn't pack the pores, just makes the catalyst inert.  Doesn't take much, but it probably does take a while.

 

That's the reason they removed the ZDDP from the oil in the first place.  As I understand things. 

[Jeff G 78]

Interesting.  Thanks for the history lesson Zed!

[Diseazd]

A picture tells a thousand words......with 5 hungry Z's to feed, I keep a couple extra quarts of VR1. You never know when they are going to ban ZDDP altogether!

[siteunseen]

How often do the Porsche guys change their oil?

 

 

The air cooled 911SC I had held 13 quarts if I remember correctly, so for my broke a$$ not too often.  I didn't drive it that much anyway, it was my "bar car".

[Zed Head]

"Bar car"?  Pickup car?  That's a lot of oil.

 

 

Just stopped by the auto parts stores, OReilly and Baxter are side by side, to check out oils.  Three big names in diesel oils, Motorcraft, Delo, and Rotella, all had notes on the bottle about how they were formulated for with low ash  for the latest emissions devices, one even said catalysts.  Could be that ZDDP is leaving the diesel oils too.  May not be the cheap option anymore.

 

Baxters had the whole selection of racing oils, except for Brad Penn and Pennzoil.  The VR-1 was $6.29 per quart, the others ranged up to $12.  Redline's synthetic oil said right on the label - not for break-in, only after 3000 miles.  Kind of implying that you need that ZDDP in there for a few thousand miles, at least.  So maybe the whole deal is to get any roughness at all smoothed away before the ZDDP isn't necessary.  Which would make sense since roughness would have extreme pressure and ZDDP is also defined as an extreme pressure additive.  Although I think it was originally added for oxidative stability.  If I remember right.  

[siteunseen]

Like a "slow" kid at a petting zoo, it pulled a lot of tail.

[S30Driver]

A little more inventory, and he could apply for membership in OPEC ...

 

[John Coffey]

Racing oils are not designed for low mileage.  The base stocks are the same as any other oil - refineries don't make special cracks of racing oil.  They just have a different additive package focused on higher rpm use and heat.  They might also have fewer cleaners/surficants.

[240260280z]

I always wondered who Mr. Lube was.... now we know