The Ford Barn

Mitch//pa · 06-01-2010, 09:17 PM

[QUOTE=Bruce Adams;19952]Interesting, Mitch.
I was led to believe, (by Shell's Chemical Support Team) that no oil meeting the SM grade level with the "Sunburst" (which is kind to Catalytic Convertors) could match Rotella's ZDDP content, since Rotella is a diesel rated oil.
Where did you obtain your information about Mobil 1?
Thanks[/QUOTE
the zinc content in mobil 1 15w50 is 1200-1300 ppm. i read somewhere this fall rotella cj 15w40 is lowering the zinc content to conform with stricter regulations. what that new spec is i am not sure.

Bassman/NZ · 06-02-2010, 05:55 AM

I believe it is around 600ppm, which is too low.
I know a large percentage of A owners still use Rotella, but diesel oils are not really that suitable for gasoline engines. They typically have a very high detergent content, and detergent does to flat tappet cams what low ZDDP does. The only thing thats saving A cams running Rotella is that the valve springs are so weak. Diesel oils are designed for larger bearing clearances than gasoline engines have. They also contain additives for things like soot control.
Since Mobil 1 is fine for newish engines but finds all the leaks on older engines, most A owners are better to use regular oil and add ZDDP, or use Kendall 20-50 or Brad Penn. These are probably the only regular oils that contain over 1200ppm ZDDP. There are racing oils, such as Valvoline that contain 1200+, but they're not really suitable for typical street use.
The need for ZDDP is still a matter of debate. In a stock engine, with stock valve springs and original cam it's probably not necessary but why take the chance? In a modified engine running high tension springs and maybe an aftermarket cam it is definitely needed. Incidentally, most aftermarket cams made in the US are ground on chinese powdered iron billets which have a very low Rockwell hardness rating. Original Henry Ford cams had quite a high hardness rating. There are a few cam makers, such as Comp Cams, who use quality American made billets.

jr-41ford · 06-02-2010, 06:14 AM

Found this article on oils.

http://www.animegame.com/cars/Oil%20Tests.pdf

06-01-2010, 09:17 PM	#21
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: Type of Oil That Can Be Used in My Model A [QUOTE=Bruce Adams;19952]Interesting, Mitch. I was led to believe, (by Shell's Chemical Support Team) that no oil meeting the SM grade level with the "Sunburst" (which is kind to Catalytic Convertors) could match Rotella's ZDDP content, since Rotella is a diesel rated oil. Where did you obtain your information about Mobil 1? Thanks[/QUOTE the zinc content in mobil 1 15w50 is 1200-1300 ppm. i read somewhere this fall rotella cj 15w40 is lowering the zinc content to conform with stricter regulations. what that new spec is i am not sure.

06-02-2010, 05:55 AM	#22
Bassman/NZ Senior Member Join Date: May 2010 Location: Napier, New Zealand Posts: 2,001	Re: Type of Oil That Can Be Used in My Model A I believe it is around 600ppm, which is too low. I know a large percentage of A owners still use Rotella, but diesel oils are not really that suitable for gasoline engines. They typically have a very high detergent content, and detergent does to flat tappet cams what low ZDDP does. The only thing thats saving A cams running Rotella is that the valve springs are so weak. Diesel oils are designed for larger bearing clearances than gasoline engines have. They also contain additives for things like soot control. Since Mobil 1 is fine for newish engines but finds all the leaks on older engines, most A owners are better to use regular oil and add ZDDP, or use Kendall 20-50 or Brad Penn. These are probably the only regular oils that contain over 1200ppm ZDDP. There are racing oils, such as Valvoline that contain 1200+, but they're not really suitable for typical street use. The need for ZDDP is still a matter of debate. In a stock engine, with stock valve springs and original cam it's probably not necessary but why take the chance? In a modified engine running high tension springs and maybe an aftermarket cam it is definitely needed. Incidentally, most aftermarket cams made in the US are ground on chinese powdered iron billets which have a very low Rockwell hardness rating. Original Henry Ford cams had quite a high hardness rating. There are a few cam makers, such as Comp Cams, who use quality American made billets. Last edited by Bassman/NZ; 06-02-2010 at 06:10 AM.

06-02-2010, 06:14 AM	#23
jr-41ford Senior Member Join Date: May 2010 Location: Pasco, Washington (USA) Posts: 241	Re: Type of Oil That Can Be Used in My Model A Found this article on oils. http://www.animegame.com/cars/Oil%20Tests.pdf