Zinc Rich Oil for Flat Tappet Cams

[71DodgeDemon340]

I think your premise is correct, but the post is a little misleading. At least to me.
This is how I understand oil ratings:
The numbers that oil is labeled with represent more than one thing, because the oil has to meet required "standards". So it gets confusing. It's like saying it's a certain shade of blue for SAE-API 10W30...lol.
I understand it as the weight of an oil primarily means that it must provide the protection (load carrying ability) of that given rating. The same number includes the viscosity rating, which is about how temperature affects it. Oil thins, or gets less viscous, with heat. Conversely it thickens, or gets more viscous as it cools.
Viscosity number denotes resistance to flow. So the higher the viscosity number, the less easy it flows at a given temperature. A "straight weight" oil may still thin as it heats. But not by much and must always provide the protection that weight oil has to per the SAE-API. I know of no oil that gets thicker as it heats up, and regardless of it's viscosity if an oil carries a certain weight rating it must provide the performance of that rating. So a "0-50" oil has to provide the protection of a 50-weight oil at 212*. Even if it's not very viscous (as in it's very thin). That being said a higher number rating is about performance, not thickness. In mineral-based oils more protection meant it had to be thicker. No so with synthetics. The first time I ran 5-50 synthetic I was terrified because it was so thin compared to the 20-50 I was running. It still had to provide the performance of 50 weight rating, but it was much less viscous. That's what frees up power: less power loss to pump it and less loss as the parts spin through it while maintaining the protection.
The "0*" or "W" number indicates the tendency of that specific oil to thicken in the cold. 30W is thicker at all temperatures than 10W. 10W is thicker than 0W, etc. So 10W-40 is a 40 weight oil which thins less when cold than 15W40 at zero degrees. It still has to protect to a 40 weight rating at 212*. Even though it's technically thinner.

Here is a decent read about it... I still don't think I "get" all of it but I think I get the gist. http://www.pqiamerica.com/apiserviceclass.htm

I was trying to give a short and sweet answer but as you know its hard to not type a book when trying to explain oil viscosity lol, thats a good article about the general information you need to know on the certification of the oil and how to look and see what specs it meets but lacks a little in explaining multi viscosity oils, you explained it much better than the article did

Heres what i found off of mobile ones site

What is oil viscosity and what impact does this have?
Viscosity is a measure of the resistance of a fluid’s flow. The thicker (high viscosity) of an oil, the slower it will flow.

Most oils on the shelves today are "Multigrades", which simply means that the oil falls into two viscosity grades (i.e. 10W-40 etc). In a 10W-40 for example the 10W bit (W = winter) simply means that the oil must have a certain maximum viscosity or flow at low temperature. The lower the "W" number the better the oil's cold temperature performance.

The 40 in a 10W-40 simply means that the oil must fall within certain viscosity limits at 100°C. This is a fixed limit and all oils that end in 40 must achieve these limits. Once again the lower the number, the thinner the oil: for example, a 30 oil is thinner than a 40 oil at 100°C.

Heres some good graphs that show the viscosity differences

15w-40

10w-40

5w-40

Sae 30

More comparison.

10w-40 vs sae 30

Right off the bat we can see the sae 30 is more dense at all temperatures from 32F degrees to 212F degrees compared to the 10w-40.

But if you look at the viscosity curve the sae 30 curves pretty hard by the time it reaches 32 degrees with a higher viscosity meaning its thicker. The 10w-40 has a less of a curve and remains much thinner at 32F degrees but both are the same viscosity at 212F.

Look at the line from 100 celcius or (212 degrees fahrenheit) to 30 celcius or (85 degrees fahrenheit) in both the 10w-40 and sae 30. From 212F degrees to 85F degrees both the 10w-40 and sae 30 are virtually the same viscosity.
Now look from 30 celcius (85 degrees fahrenheit) to 0 celcius (32 degrees farhenheit) in both the 10w-40 and sae 30, we see that once they both hit 85F degrees the sae 30 rapidly gets thicker all the way down to 32F degrees more so than the 10w-40. Thats why the 10w40 will appear thinner in colder temps, realistically all these weights should appear about the same viscosity when poured at anything above 90F degrees, it seems as though when the temp goes below 85F degrees thats when the winter rating comes into affect as below 30 celcius (85F degrees) the 15w-40 progressively gets thicker more so than the 5w-40 which remains quite a bit thinner down to 32F degrees

 

[fastr1]

My suggestion is use Schaeffer racing oil or their 7000 series that is fortified with tons of Moly, this company is the oldest USA oil company that is little known outside the industrial industries or people in the know, they spent money on product to reduce downtime and repair in industry and kept their product priced right not wasting it on sponsorship and mass qty advertising. Trust me and ask around those in the know will tell you nothing but great things, me included.

 

[S'cuder]

A few are having trouble with some of the concepts of how oils, straight grade and multi-viscosity relate to temperature. 71DodgeDemon340's charts are excellent, but are extremely detailed, so I'm going to put out some basics.
Oils thin as they are heated, and thicken when cooled. That's just common sense, and we all get that. The difference is that multi-grade oils do this at a slower rate, which allow them to flow cold equivalently to a SAE 10W at 0*C, and yet have the same thickness as a SAE 30 at 100*C.
Please see the attached chart for a simplified illustration. I've used versions of this hundreds of times over more than 30 years, and it has never failed to help folks understand.

 

[fjr]

Ok everyone! I know this has been beat to a pulp. But currently what oil preferably conventional is good enough to run in a 360 with stock clearances? I have been using 30 weight vr-1. But need other sources of oil please!!

There are a lot of good replies here already but I'll put in my 2¢.

While flat-tappet engines require ZDDP, those with oem-style valve trains don't need huge amounts. The thickness of the ZDDP layer doesn't depend on ZDDP concentration. Since the layer is sacrificial, more ZDDP really just extends how long you can run the oil. Engines with high valve lifts and spring pressures consume ZDDP additives at a faster rate than milder engines. See Engine Oil Myths - GM TechLink and Engine Wear.

For valve train protection, Heavy Duty Engine Oils are better than racing oils because they also have high ZDDP levels but have better detergents and will keep an engine cleaner for longer. See the Corvair Oil Guide. 30-grade oils that are approved for API CK-4/SN are considered resource-conserving and are limited to 800 ppm of phosphorus but 40-grade HDEOs (like 15W-40) are limited to 1200 PPM even when approved for API SN. Phosphorus is the antiwear component of ZDDP.

I run semi-synthetic PetroCanada SHP 10W-30 in my car because it uses the SHP 15W-40 additive package so it has the high ZDDP level of a API CK-4 oil and meets the 1000+ PPM requirement of Ford WSS-M2C171-F1 but is good for gasoline engines because it is suitable for API SN.

 

[S.Rodney]

Hey S. Rodney! Is quaker defy still around? I have looked for it and not much luck.

Unfortunately, the QS Defy (which had about 1070 ppm of zinc) has been replaced by QS High Mileage (which I've heard has a bit less... around 890 ppm)

I still have 4 quarts in my Trunk (of Defy) so... that'll be it after that.

So, you could take a look at AMSOil's Z-Rod.

Also, I did talk with an engineer at Shell in Texas (you can contact them at pqstechnical-us@shell.com)
They recommended Shell Rotella-T 15w-45
(SOPUS owns "Shell", "Quaker State" and "Pennzoil"... they also make most of Canadian Tire's "Motomaster" branded oils)

 

[S'cuder]

There may have been more than a few inquiries or complaints about Quaker State discontinuing their Defy oil. On this web page, they assert it was only a packaging and name change.
New Green Bottle – Same Reliable Oil

 

[Mattax]

@71DodgeDemon340 If you can find the 10-40 vs 30 chart that's missing, the text would be easier to understand.

If not, here's a similar pair of charts snipped from Widman's Oil for Corvairs.
I've added some notes to show why multi-weights are better for starting and warm up in cold and moderate temperatures.

Once an engine is warmed up, we have to zoom in to see the differences.

In terms of viscosity at operating temperatures, a straight SAE 30 and a multi-weight 10W-30 will be almost the same.

The graph is just representative. For any 30, 10W-30, or even 0W-30, the viscosity at 212 F can be 9.3 to 12.5 cSt. If you want to know exactly, then you need to get the spec sheet or have the oil tested.
Note: I've taken the liberty to extend Widman's 'Zone of Protection' from 12.5 cSt. to 15 cSt to represent the wider range Chrysler seemed to have allowed for its water cooled engines versus the air cooled Corvair engines.