GM EOS and Diesel oil…

[dust]

After reading many threads on multiple forums and other real life sources, I concluded that:
For flat tappet engines, you must use diesel oil OR conventional oil with GM EOS to prevent excessive cam wear due to lack of vital ingredients (mainly zinc).

But today I was reading the Hot Rod September 2006 issue about a Chevy 500HP build. They used Rotunda diesel oil and a qt or GM EOS.

Any ideas on why they did this? Or am I mistaken and you have to use EOS w/diesel oil?

Sorry, another oil threadÂ

[TK]

LOL.

Well, I use castrol, and STP. Seems to work great, unless it is this one cam manufacture, which I will never, ever use again.

You don't have to use diesel oil with the additive from GM, according to GM, I just think it helps.
Rotella isn't the greatest oil though, if you are using diesel oil, I would use Del-Vac, or DELO. Valvoline premium blue is a good one too.

[451Mopar]

I usually use regular engine oil with EOS or Mr. Moly (simular to EOS, but alot cheaper.)
The Deisel oil seems to have a higher amount of zinc, and so people are using it for engine break-in.

[kamstra]

Dust

A good friend, I trust got me to use Rotellla T in my engine. The extra zinc helps reduce wear and helps with flat tappet lifters

I had a friend wipe a cam recently with his new install, He was using Standard oil and EOS. He used Rotella on the second cam with no issues. I cannot say that Rotella made all the difference but it did not hurt.


You can use both EOS and Rotella for Extra Zinc and phosphorus. You can but do not have to use both. I just use the Rotella

[George G. Leverette]

I think we have two issues the EOS is used for engine break-in because it adheres to the surface better than other lubes. The Rotella is for long term use with flat tappet cams because it provides a high zinc content. Synthetic oils are reputed to have an additive that subs for the zinc.