Zinc phosphate in engine oil

[Mark H.]

Re: Zinc phosphate in engine oil

I've just been walking over to the wall of motor oil and picking up each bottle and reading the Donut info looking for CJ-4/CI-4.

Did it again at a different AA this morning while I was picking up some fuel line. Didn't see the above mentioned Castrol either.

Oh well. Like any other Corvette guy, I don't give up easy.

Thanx again for sharing your considerable knowledge on the subject.

Mark

[Steve B.]

Re: Zinc phosphate in engine oil

I personally use vavoline 20 50 vr racing oil. It contains 1300 ppm zinc and is formulated for gas engines, just my preference.

[Duke W.]

Re: Zinc phosphate in engine oil

If the Zn analysis is 1300 PPM then the P analysis should be in the range of 1150-1200 PPM, which is about the same as CJ-4. For a given level of P the Zn is usually in the range of 100-150 ppm greater.

Some "racing oils" are formulated with little or no detergent/dispersant because they are designed for short life - one race. These oils likely do not carry an API service category certification and are not suitable for road engine use. Do your due diligence!

I recently ran across some infomation that implies that C-category oil has "too much detergent/dispersent" that reduces oil film strength making a vague reference to some published research without any detals, and this means that high performance gasoline engines run "too fast" for C-category oil. This is all nonsense!

HD diesel engines are governed at relatively low revs (typically 1800-2100), but they have much larger diameter bearings, so surface velocity at the bearing is similar to automotive gasoline engines except at the very top end of the rev range.

Just like too much ZDDP can cause problems, issues can rise with too much of any additive, but the fact that primary C-category oils carry a secondary S-category rating is proof that they are "safe" for gasoline engines.

As I've stated many times before, current primary category SM oils are formulated for currently produced engines, which have different requirements than vintage engines. In addition to modern engines needing less ZDDP due to their "roller everything" valvetrains, modern engines don't need as much detergent/dispersant as vintage engines because modern engines warm up faster, have much more precise fuel flow control, and generally less blowby than vintage engines, so they see less crankcase dilution, which detergents/dispersants keep in check.

The detergent/dispersant level can be compared by looking at the Ca (calcium) analysis, and C-category oils have traditionally been higher than S-category oils.

Another analysis result you will run across is TBN - total base number. This is an indication of the oil's ability to neutralize acids. Prior to CJ-4, C-category oils had very high TBNs because they were formulated for use with traditional high sulphur diesel fuels. All road diesel sold in the US is now low sulphur - about the same level as gasoline, and CJ-4 was specifically formulated for low sulphur fuel, so the TBN was reduced relative to CI-4, but it's still typically a bit higher than SM oils.

Of the major oil marketers, Chevron appears to publish the most comprehensive spec sheets for their engine oil products.

Duke

[Steve B.]

Re: Zinc phosphate in engine oil

Duke, that is a good point with regards to some of the race oils having less detergents/dispersents. This is true with Vavlolines not street legal race oil. It has a higher zinc content than the vr but its good for only 500 miles. The VR race oil is good for 3K miles 3months like most regular oil products. You are a true asset to this forum

[Mark H.]

Re: Zinc phosphate in engine oil

Found a source close-bye for both Delo and Rotella this afternoon.

[Steven B.]

Re: Zinc phosphate in engine oil

'Some additional info on zinc-dialkyl-dithio-phosphate, ZDDP, at www.zddpoiladditive.com, elimination in some oils and availability as an additive.

Steve

[Duke W.]

Re: Zinc phosphate in engine oil

Let's get this straight once and for all.

ZDDP HAS NOT BE ELIMINATED FROM CURRENT ENGINE OILS!!!

It has been reduced and the details about the reduction for the two service category oils are in the current Corvette Restorer article, and anyone who can post to this web site should have a copy of the magazine.

Beware of marketing and advertising. Much of it just promulgates the same old myths and misinformation like the "elimination" of ZDDP!

Duke

[Stuart F.]

Re: Zinc phosphate in engine oil

The October issue of the Corvette fever Magazine has "another voice" heard from on the subject on Page 75, Resto Clnic, in answer to an inquiry. Don't exactly know who the responder is, but it is an extensive write up for the column. He claims, among other things, that CJ-4 won't do any good. Interesting reading on the subject. Guess this just can't be put to bed.

Stu Fox

[John F.]

Re: Zinc phosphate in engine oil

I have been using Valvoline oil since my first car rebuild (1955 Ford). Used it in a 56 & 62 corvette back in the late 60s-early 70's. Have been driving Toyota camrys for years with Valvoline SYNpower full synthetic 10w-30 with no problems. Now that I have a 62 again I continue with the same.

[James B.]

Re: Zinc phosphate in engine oil

Duke,

I too, live in Southern California. Just curious, what weight of CJ-4 oil do you recommend for a street-driven vintage Corvette engine for year-round use?


James

[Stuart F.]

Re: Zinc phosphate in engine oil

John F.:

I am crushed! you mean to tell me your Toyotas aren't completely maintenance free? Boy! Have I gotten the wrong perception. To watch them wipe up everything in NASCAR with their Chevy R07 engine copies, I thought they could do it all without even changing oil. I was just about ready to go out an order one now that my GM Retiree health benefits are going away - figured they went to Toyota.

Stu Fox

[Duke W.]

Re: Zinc phosphate in engine oil

Duke,

I too, live in Southern California. Just curious, what weight of CJ-4 oil do you recommend for a street-driven vintage Corvette engine for year-round use?


James

Didn't I provide the necessary information in the article for everyone to select a suitable viscosity range?

Take another look. What do you think?

Duke

[Jim D.]

Re: Zinc phosphate in engine oil

The October issue of the Corvette fever Magazine has "another voice" heard from on the subject on Page 75, Resto Clnic, in answer to an inquiry. Don't exactly know who the responder is, but it is an extensive write up for the column. He claims, among other things, that CJ-4 won't do any good. Interesting reading on the subject. Guess this just can't be put to bed.

Stu Fox

As if anyone believes anything printed in that POS rag. It always has more mistakes than first graders doing calculus.

[David D.]

Re: Zinc phosphate in engine oil

Today's Zerex G-05 is completely different than any antifreeze product available in 1975, and the industry consensus is that it is the best replacement for traditional "green" antifreeze for older cars that have a wide mix off cooling sytem materials - iron, aluminum, brass, solder. It will provide superior protection without precipating out deposits that will eventually clog tubes like green.

Most antifreeze products are ethylene glycol based, but the big difference is the corrosion inhibitor package. "Green" is known as an IAT and G-05 is an HOAT. And then there are OAT types like Dexcool.

More info in the archives and on the Web.

Duke

Duke,
Not to take this back off topic yet again, but I gather you are saying that the Zerex G05 is thee stuff to find and use? vs. what I just bought was Prestone (I assume the Greem stuff).
I haven't bought anti-freeze in forever, but when I went to pick some up I was amazed that everything out front was a 50/50 mix? I asked the guy if he had the straight stuff. BTW-same price and size as the 50/50 mix (Go figure). He said sure, but it was tucked off to the side a bit. I asked him if people just can't figure out the 50/50 mixture deal and he just laughed and shook his head, as if to say, oh well it takes all kinds.
So....bottom line what is it I (we) should be looking for in Anti Freeze these day?
Thanks yet again,
David

[Stuart F.]

Re: Zinc phosphate in engine oil

Jim;

With all due respect to your low member number, not that I'm waving the flag for any particular magazine, but you should be aware there are some fairly heavy hitters on the CF editorial staff - a number of which are well known and respected NCRS members. If you disagree with any of their points, you should offer counter information/proof to dipute what they put in print. We are all free to read what sources we wish and digest the information as presented, but in the end make up our own minds. I have personally followed a number of our most respected contributors on our TDB and found some of their information in conflict with my own experiences. I respect their credentials, their knowledge and experience, but will consider much of what they say as theory to me until and if I can prove or disprove what I question.

Stu Fox