Is zinc oil really necessary for our engines

[Per Lundgren]

In 2010, a question was asked in Classic Motor (a Swedish car magazine) if low levels ZDDP in engine oils is harmful to older engines. A part of the answer was this:

“Classic Motor has been in contact with a technician at Swedish Shell who says that no real case has so far been reported to them. On the other hand, there is plenty of rumors on various internet forums about these oils that are believed to be harmful to the camshafts on older engines. There is, of course, a grain of truth in all these rumors, but this seems to be mainly a US problem”

That being said, which of the following two engine oils do you think I should choose for my Porsche 356 with newly renovated engine that only runs during summertime. I don´t write the brands because they are only sold in northern Europe.
- Mineral oil 20W-50. Zinc 2200 ppm, phosphorus 2000 ppm
- Mineral oil 20W-50. Zinc 1100 ppm, phosphorus 1000 ppm

The Porsche factory recommends us to use 20W-50 olja in our engines so I stick to that
https://shop.porscheusa.com/porscheoem/ ... 20929.html

[John Clarke]

Isn't there a Sticky on this subject?
All items covered?

[Jim Clement]

Some good reading from Registry May - Volume 31

V31229 oil comments from Duane S.pdf

(568.98 KiB) Downloaded 16 times

V31125 LN on 356 Oils.pdf

(489.79 KiB) Downloaded 10 times

V31124 356 oils.pdf

(537.46 KiB) Downloaded 9 times

Both Duane S / John Wilhoit, and my engine rebuilder - Jack Moris all recomend Swepco 306 , I see that it also has the highest Zinc levels..

[Jim Liberty]

I've used high zinc oil (20W 50) "Racing" oil on dozens of cars, (engines). We have never had a camshaft failure. .......................Jim.

[Per Lundgren]

Thanks for all comments and links.
To be on the safe side, I will buy the oil with 2200 PPM zinc for the engine I am building for my Porsche 356.

But if ZDDP in the oil is so important, I don't understand why my SAAB (from the early 2000s) doesn't have problems with the camshaft and valve lifters. It does have overhead camshafts, but otherwise the design looks very similar to that of my Porsche 356. A camshaft that presses on a valve lifter. See picture.
I have never heard of problems with camshafts and valve lifters on a SAAB regardless of the oil used