Helios59

I'm back! It's been a few months since I posted...my car was in the shop getting a new transmission. Took forever to find a good rebuild-able '86 core. I'm back on the road...can find 5th each and every time...and no more howling from bad bearings. Finding 1st is still hit and miss and my 5th-to-4th downshift can be tricky. New bushings are on the to-do list and a Seine gate shifter may also be in my future.

I also switched from 20W50 to 15W40 and have enclosed my Blackstone oil analysis. This is the second sample I've run by them. Copper and lead are up; silicon is down. Bad bearings are the likely culprit. What's the consensus on oil change intervals...should I change in 3K miles or is 5K fine? I only put about 5K on the car yearly.

Hello to all

No HTwo O

Well, you only have 2 UOA's, but the last report is telling you something. Too bad you don't have more UOA history. From your last report, either your Porsche does not like the Brad Penn or something has changed significantly in your engine's internals (or your driving style).

Based on the spike in your copper and lead levels, I would not go 5,000 on this interval. BP is a great oil. I'd expected better numbers. You may be due for a top-end sooner than later.

No HTwo O

This is a typo, right? You went from the Valvoline 15W40 to the Brad Penn 20W50. BP is a blended oil, not a full sythetic. What was the Valvoline? This may have contributed to your elevated wear metals.

If you want to run a 20W50 oil, full sythetic, maybe consider the Mobil V-Twin. I run this in my Turbo. UOA's are excellent. 5,000 mile intervals.

TheMystro

X2. Why wouldn't you want to run full synthetic?? Check out Royal Purple. It's the best full synthetic with the added zinc/phosphorus. The allegiance to BP baffles me when there are much better oils out there.

http://www.royalpurple.com/product-c...!hps-motor-oil

bgiere

You need to do many UOA's to identify trends...Switching oils and doing two UOA's tells you almost nothing about the condition of your engine. Pick one oil and run it for multiple drain intervals...then you may have some data that's worth something.

theiceman

i doubt its a typo ... BP also has a 15w40 oil . I use it in the spring and the fall as we have cooler weather then, and i have no need to run 20w50 and it actually becomes too thick.

I dont run synthetics and never have .. these cars bearing clearances were designed around oil available at the day when synthetics didnt even exist. The only real advantage of synthetic in my mind is the oil is artificailly structured into a linear molecule.

Synthetic oils allow for smaller bearing clearances , allow for easier starting and reducing emmisions as well as going longer before breaking down.

If you are changing every 3-5K you dont need long life oil anyway ..

If you want to pour money into your cranckase for nothing more than peace of mind go ahead knock yourself out.

The 20/50 form BP is semi synthetic but i dont use it because of that , it just happens to be the oil I chose because of the high zinc and phosphorus levels.

I have never used synthetics and i only have used BP for the last 3 or 4 years. before that it was always a good quality dyno changed every 5 K

I have 250,000km on my car excellent compresion i use about 1 quart per 5,000 km maybe ... I dont need an oil analysis to tell me what is going on . Great if you want to do it but just leads you to worry about more, with very tiny pieces of random sample evidence you are trying to make decissions on.

KNS

Interesting to see how low the zinc and phosphorus are in the Valvoline compared to the Brad Penn.

The copper reading was elevated a bit on my last analysis as well. I'd like to know what the reason is...

theiceman

i have used VR-1 if i cant get the BP. No real issus here and is on my "approved" list