I was talking with a friend about oil a few days ago. Since then I logged on to the Kendall Oil site in the following steps:
1. Google "Kendall Motor Oil.com"
2. Click on "Kendall Motor Oil Online"
3. Click on "New Product Data Sheets"
4. Click on "Automotive Engine Oils"
5. Click on "GT1 High Performance Motor Oil"

At this point is Kendall's story, including their claim to have fortified their oil with additional ZDDP additive. Scroll down the page until you reach a side by side comparison of GT1-20/50 and a lighter weight GT1. (1) I realize that this site was last updated in 2006. (2) I've been a fan of Kendall products (I know that they are now Conoco-Phillips) for many, many years.

If you would be so kind, could you comment on the following (I'm only concerned with the 20/50 version of the basic, non-synthetic GT1 as it applies to 1989 and earlier Porsche 911s).
1. Is Kendall's published information for the 20/50 GT1 consistent with your testing?
2. Do you find anything in the Kendall chart, or in your own testing, that would cause concern over using GT1 20/50 in either a weekend toy, or a daily driver.

The reason for these questions is that I never saw cam/rocker failures at my shop (which I sold in 1999) in Kendall engines. I know that some SoCal shops still use and rely on Kendall 20/50 (I realize that viscosity is not suitable everywhere in the USA and Canada, and that the ZDDP story changes with the lighter oils), and I'm not getting any cam lobe failure feedback regarding engines that use 20/50 GT1.

I want to thank you for your past posts, and I apologize for my questions, although I think a more specific approach (discussion of only one oil) might help to further clarify this issue.

Best Regards!

 

Hey Pete,

Sorry for not responding sooner.

Long story short, the Kendall product you were using around the time you sold your shop is closer to the current Brad Penn than what is being sold today. The old Kendall/Amalie product that was in distribution probably was being phased out and replaced with Conoco/Phillips products somewhere around the new millennium.

I can somewhat recollect somewhere around 2000/2001 Kendall going to a Gold color, at which time the formulation changed. I know of some shops that at that point started having high rates of non-catastrophic cam/lifter wear which have since been resolved by their switching to Brad Penn.

To my best knowledge, the new(old, been around since 2000) Kendall GT-1 20w50 is nothing special, with ~1200 ppm Zn/P and a Ca based detergent. The lighter weights have only ~600ppm Zn/P, on the low end of the SM scale, so I'd never use them in anything on mine. I'd venture to say that all things considered, the aforementioned M1 current reformulated 15w50 is probably a better oil than the Kendall product and that there are still better oils out there than both.

If you want the old "green" Kendall/Amalie oil, Brad Penn is what you are looking for.

From Brad Penn's site:

"In 1997, American Refining Group, Inc. (ARG), a privately held energy company headquartered in Philadelphia, PA, purchased the Kendall/Amalie refinery located in Bradford, PA, from Witco Corporation. As a result of the sale by Witco, of the Kendall® and Amalie® brands to a third party, a new name was given to the products produced at the site: Brad Penn® Premium Pennsylvania Grade Lubricants."