ZDDPlus

[Joe C.]

Re: ZDDPlus

Duke and others:

The W rating for motor oils is the viscosity at 0 F and not 0 C (or 32 F). Those without the W are rated at 212 F as stated.

Agree with Duke that 20W-20 was the (generally accepted) straight weight factory fill during the early-mid 1960's. Not sure when the factories went to multi-weight.

During the 1960's when multi weight oils generally became popular, there were problems with the viscosity index additives not lasting very long. Many (self included) continued to run straight weights in their engines.....switching viscosity grades with the seasons.

Larry

Actually, the "W" stands for "winter rating", and the test temp varies as the viscosity.......it does not necessarily mean that it is tested at any specific low temp. The low temp varies from minus 5 to minus 40 degrees F. The high temp viscosity is always tested @ 212 degrees F. (100 degrees c)

[Larry M.]

Re: ZDDPlus

Actually, the "W" stands for "winter rating", and the test temp varies as the viscosity.......it does not necessarily mean that it is tested at any specific low temp. The low temp varies from minus 5 to minus 40 degrees F. The high temp viscosity is always tested @ 212 degrees F. (100 degrees c)

Joe:

You are correct. The current SAE J300 Specification has a sliding scale for the temperature used for testing W (winter) rated oils.

However, it was not always this way. During the 1950-60's when testing was not as sophisticated as it is now, W rated oils were tested at 0F and the viscosity compared to a standard range to determine the W viscosity rating.

Internet data searches show both methods/standards. The current/latest one should, however, take preference.

Larry

[Duke W.]

Re: ZDDPlus

Here's a chart of absolute viscosities for winter grade oils, but I'm not sure if it is current:

http://www.infineum.com/information/viscosity.html

The standard ring package for vintage Chevrolet OE engines (and I think it was used industry wide for automotive gasoline engines) consists of 5/64" wide top and second compression rings (not 5/32") and a single 3/16" oil control ring.

I've seen HD engine designs with up to three compression rings and two oil control rings, but those engines operate at low mean piston speeds - on the order of 1200-1800 FPM.

Piston rings design in a high speed engine can be tricky due to a phenomenom called "flutter" where the rings start vibrating and no longer provide an effective seal. Thin rings, low ring tension, and excess land clearance can exacerbate flutter.

Duke

[Joe C.]

Re: ZDDPlus

Here's a chart of absolute viscosities for winter grade oils, but I'm not sure if it is current:

http://www.infineum.com/information/viscosity.html

The standard ring package for vintage Chevrolet OE engines (and I think it was used industry wide for automotive gasoline engines) consists of 5/64" wide top and second compression rings (not 5/32") and a single 3/16" oil control ring.

I've seen HD engine designs with up to three compression rings and two oil control rings, but those engines operate at low mean piston speeds - on the order of 1200-1800 FPM.

Piston rings design in a high speed engine can be tricky due to a phenomenom called "flutter" where the rings start vibrating and no longer provide an effective seal. Thin rings, low ring tension, and excess land clearance can exacerbate flutter.

Duke

Modern applications use the 1/16" rings with standard tension for street use.

A common race ring set would be .043" wide with low tension. In cases such as this, special pistons with gas ports are used, which pressurize the top ring land, ensuring a very tight seal. The tradeoff here, is that ring durability is greatly reduced, necessitating changeout much more frequently than would be practical for street driven vehicles.

[Ron N.]

Re: ZDDPlus

VALVOLINE - VR-1 RACING MOTOR OIL / VALVOLINE - ZEREX

Duke, Bill & others, after reading many articles and forum posts I had major concerns regarding motor oil and coolant re-formulation. I did some research on motor oil and coolant products available on the ILSAC, API, Oil Company, other related sites and articles. To keep it simple I settled on 2 products (among many) that I believe would provide the quality and protection for my 67 Vette (original 327/300 (stock), original radiator, about 80k miles (never raced). Being a layman, the advice / comments from subject matter experts on these 2 Valvoline products & questions would be appreciated.

is zinc/phosphorus (.14/.13) and detergent level acceptable / too high?

2. VALVOLINE - Zerex ?

[Duke W.]

Re: ZDDPlus

I recommend Zerex G-05 and have given all the whys and wherefores before.

Commonly available CJ-4 and CI-4 engine oils have more than enough P and Zn (measures of the amount of ZDDP anti-wear additive) for vintage engines, either original or freshly restored. There is no need to shop around and pay extra for any kind of "boutique oil".

I hope your research included my engine oil article published in the Summer 2008 Corvette Restorer. It was also in another publication that is online. A link to it is in a recent thread on the subject, or just google my name along with "engine oil".

Duke

[Bill S.]

Re: ZDDPlus

what about hyper lube? i remember that in a fairly recent post that rotellla no longer had zinc zt all and had not for a while i assume the CJ was the zinc rotella and ci w/o. hyper lube said it would satisy the needs on any solid lifter cam. i have an L72

[Jean C.]

Re: ZDDPlus

Bill, suggest you visit the Shell and Chevron websites (Chevron is www.chevronlubricants.com , not sure what Shell is) to view the specs on the Rotella and Delo oils respectively.

Also suggest you refer to Duke's post yesterday at 1008 hrs. Read Duke's article on engine oils in The Restorer for info on this subject.

Cheers,

[Bill S.]

Re: ZDDPlus

i don't see a post by duke at that time what was the post subject?

[Duke W.]

Re: ZDDPlus

[quote=Bill Snyder (46851);409332}i remember that in a fairly recent post that rotellla no longer had zinc zt all and had not for a while i assume the CJ was the zinc rotella and ci w/o.[/quote]

You must have read that on The Corvette Forum. If you want to learn the facts about engine oil (not just a bunch of myths and misinformation) follow Charlie's advice. Read The Corvette Restorer article, and just search the recent archives on this site.

Duke

[Jim T.]

Re: ZDDPlus

Joe 32899 reference your mentioning of piston slap. 85 Corvettes have forged pistons and my 68 original 327/350 has them as well.
I have not heard any piston slap on start up with these engines.
The 85 has about 102K and he 68 has 98K.

[Jean C.]

Re: ZDDPlus

Bill,
Duke's post is in this thread following a post by Ron Napoliello and before a post by Dave Perry, date of Duke's post indicates "Yesterday, 10:08AM".
Best regards,

[Bill S.]

Re: ZDDPlus

duke, i almost think that was the artical that enlightenedme to the fact not all rotella had zinc and the difference between CJ and CI. i read all Restorers cover to cover. any thoughts on the new Hyper lube product? i just put in a bottle with castrol gtx 10w 30 in my 66 L72 . it has about 1000 miles this was my 3rd change. i used the gm additive for break in.

[Joe C.]

Re: ZDDPlus

Joe 32899 reference your mentioning of piston slap. 85 Corvettes have forged pistons and my 68 original 327/350 has them as well.
I have not heard any piston slap on start up with these engines.
The 85 has about 102K and he 68 has 98K.

Piston slap much less likely if forged out of 4032 aluminum, as can be run with closer tolerances of about .003". Production pistons for street use are mostly made from 4032.

For race or severe duty applications, pistons are forged out of 2618 aluminum, which has a higher expansion rate. Consequently, the larger clearances necessary to accomodate their use (typical .005"-.006") will cause noticeable slap during warmup. Pistons made out of 2618 are not appropriate for street driven cars, unless they use pressurized induction.

[Duke W.]

Re: ZDDPlus

duke, i almost think that was the artical that enlightenedme to the fact not all rotella had zinc and the difference between CJ and CI. i read all Restorers cover to cover. any thoughts on the new Hyper lube product? i just put in a bottle with castrol gtx 10w 30 in my 66 L72 . it has about 1000 miles this was my 3rd change. i used the gm additive for break in.

I suggest you reread the article. I have no idea what "Hyper lube" is, and I've read enough marketing BS from various additive and boutique oil marketers to be thoroughly nauseated by it all!

Once again, I recommend CJ-4 or CI-4 engine oil with no supplemental additives other than a bottle of GM EOS or equivalent for fresh engine breakin, and I would not bet that there is any magic elixir out there that will make me change my recommendation.

Of course, ultimately everyone has to make their own decision on what fluids to feed their cars. I try to give everyone an objective view of the engineering and science behind automotive fluids. That's the best I can do, and I'm not trying to sell any specific products to anyone, nor do I have any financial interest in any product that anyone might buy, other than from time to time owning highly diversified mutual funds, which always include equity and/or bonds of the major oil companies.

Duke