Break-in Oil Question

[CV355]

I searched through old threads and found some good info, but I don't know if it applies to my situation.

My 484 FE has been running since October 2021 and I have put a whopping 445 miles on it.  I have changed the break-in oil annually (Maxima Break-in 10w30) and it comes out clean (gee, I wonder why).  On other new or rebuilt modern engines, I'd run break in oil until 500mi and then switch to synthetic.  I was warned against doing this on an FE but not told why.  What should do I do for a roller FE?  I'm seeing a lot of people recommend VR1 but the range of weights is all over the map.  Any recommendations?   

[jayb]

I always use 10W-30 VR-1 with new motors, and have had good results with that.  Since your engine is broken in synthetics would be OK, but there are a lot of reports of oil leaks developing after the installation of synthetic oils.  The sealing systems used on an FE are not as good as those on modern engines, and that may be why there are these leak reports. 

[CV355]

I always use 10W-30 VR-1 with new motors, and have had good results with that.  Since your engine is broken in synthetics would be OK, but there are a lot of reports of oil leaks developing after the installation of synthetic oils.  The sealing systems used on an FE are not as good as those on modern engines, and that may be why there are these leak reports. 

I appreciate it, I'll give that a try this weekend.  I had a feeling it had to do with leaks and sealing methods in an older engine platform, even with modern machining and componentry.  A lot of people are swearing by 20w50 on FEs but I generally try to avoid going that heavy on anything but my tractor.

[Rory428]

I have been using Brad Penn/ Penngrade 1 oil in my flat tappet FEs for many years, since before all the flat tappet issues and low ZDDP levels became an issue. Prior to then, I had always used regular conventional oils with a bottle of the original GM EOS additive on new cam break ins.  In recent years, I have used Brad Penn break in 30 oil, as well as a bottle of EOS (When I heard that GM was changing the formula of the EOS, I bought 2 cases of the original blend). After the cam break in, a few Dyno pulls, and a couple hundred miles, I switched to Bradd Penn 10/30 oil.The Brad Penn is a "semi synthetic" oil, and my most recent 428 has 3 years and about 3500 miles since I built it, and no oil leaks.

[1967 XR7 GT]

The Brad Penn oils, such as the 10w-30, 20w-50 and even their SAE 70w and their other oils still have levels of the minerals such as phosprous & zinc, just not at the level of thier 30w break-oil. And their multi grade oils are a Semi-Synthetic Blend.

The full synthetic blend oils are thin and tend to have leak issues, from what I've seen. I, am happy with the Brad Penn oils. My water cooled motors I run their 20w-50 Semi-Synthetic Blend, and my air cooled motors I run their SAE 50w here in So California.

[Porkchop]

Is there a specific PPM of zinc (or phosphorus and moly) that is recommended? I have read generically (not specific to FE's) 1500 PPM for break in, 1000 PPM afterward for a non roller cam.

Valvoline VR-1 data sheet shows 1100 PPM. And I happened upon a review claiming they reduced Zinc content from 1400 to 1100 PPM recently.
https://sharena21.springcm.com/Public/Document/18452/a90245ef-03ba-ed11-b81d-48df3793b338/ec3c3f0d-04ba-ed11-b81d-48df3793b338
https://www.valvolineglobal.com/en/vr1-racing-oil/

Couldn't find anything for PennGrade.

Also looked at a couple of additives (Howard's/Rislone). If you spread their small volume across 5-6 quarts of oil, you get about 1000-1500 PPM.

What is the harm in running a break in oil with an additive on top for good measure?