FWIW, many of us have spent considerable time researching suitable engine oils for our '91 and earlier flat tappet engines that require the additive ZDDP or Zinc/Phosphorus to help prevent wear. Cross posted on the 911/964 forums.

Without getting into a mile long thread or debate on the subject, I thought that those interested would enjoy seeing an actual oil analysis of a DE tracked, 3.6 engine.

Notes:
A...20-50 Valvoline VR-1 Racing oil
B...55,000 miles on engine
C...Oil and filter change every 4th event
D...Analysis is from 1,000 track miles on the 2.9 mile road course at Texas World Speedway and the 2.8 mile course at Mid Ohio.
E...The time period was from April thru September of this year.
F...Blue (C) and Yellow (B) run groups
G...Engine pulls hard all the time, rarely falling below 4500 and continually up to 6800, oil temps typically run at the 8:00 position and at the hottest hit the 9:00 position.

Attached are the Blackstone Oil Analysis and PDF Spec sheet from Valvoline on the oil...

 

Impressive results...but...the oil hadn't been in long, so presumably the trace materials increase with engine running time...so it suggests that you're changing your oil too early?

 

I have a Blackstone sampling kit on the shelf. I will try a test next oil change.. but I am afraid to see what the results will indicate... My car is nearly at 200K...

 

Actually, in the DE only environment, with prolonged hi rpm for a cumulative 1000 miles, coupled with a 5-6 month change interval, I'm thinking I may actually need to change it every third event.

 

How/ where do you take the sample from? Engine running, from the file tube via vacuum pump with suction hose mid level?

 

I take it from a hot engine (driven on the road for 10 miles or so. Then catch samples MID DRAIN from both the crankcase and the T-stat / pressure regulator drains. Yep you'll likely make a 'small' mess. Get a large pizza pan or similar pan to catch what the drain pan misses.

Wear safety glasses, long slkeeves and gloves, the oil is damned hot!

 

It will be very intersting to see what things look like. I bet you will be pleasantly surprised by the results.

Btw, how many of those miles did you put on the car?

 

I got the car 2 years ago at ~160K

 

Just do it Tom! I also think that you will be pleasantly surprised.