Hi Woody,
Back in the days when I was building racing engines, I used nothing but straight grade 20w Havoline. At the time I did the research on the break in oil, Havoline had the fewest addatives and more pure lube than anything else, and it was cheap. I would run the new engine for 10-15 minutes at 3000 rpm and watch the temperature and oil pressure, then shut it down and change the oil and filter. Then, I'd repeat the process. I also used nothing but WIX filters. You'll be amazed at how much crap is still in a "perfectly" clean engine, so two run-in oil changes were a flush,
too.
Every engine got a Melling HP oil pump, too. Then it was up to the owner to run what ever oil he thought best.
That was 30+ years ago, but I still stand by the process. About 15 years ago I built a stock Ford 300cid L6 using the same process. Today, it has over 300,000 on it and the head and pan have never been off!
Please remember, NEVER let a new engine idle until the rings and lifters have seated. It is also a good idea to turn the engine over until you get oil pressure on the gauge before you start it.
Any variation in temperature or oil pressure outside of normal, shut it down immediately and find out why. Remember, a "new" engine always runs a bit on the warm side until it brakes in.
best wishes,
Les
