ok - so on my 86 motor I am rebuilding for my 89 SPG - what would be ideal break in oil?? I typically run 10W-40 now a days on the 9000 i have done 10W-30 in the past. Which should i use to break it in - then continue running it on. Keep in mind I am fairly cheap on things - but at the same time I get name brand and quality. Currently I run Exxon Oil - have used Mobil (not 1) as well as Penzoil and Quaker State. Those are my brands I varry on. I am consistant with my AC Delco oil Filters however. All the cars I own get one at every oil change (about 3,000 miles)
I actually work for Walmart TLE, and I swear by full synthetics for new engines. As long as you don't go back to non-synthetic from full, then your good.
I actually use Redline 5W-30 (made for turbocharged engines), and its the best oil i've ever used. Before i started using Redline I tried basic Penzoil (non synthetic), and i noticed a huge difference. My car sounded horrible. I'll never go back to non synthetic.
The reason for this is that the particles in a non sythetic are not uniform is size. Therefore they break down at different times. Compared to a full synthetic that break down at a uniform rate.
The guys on the bobistheoilguy site tend to be freaks..total oil freaks who mix their own blends and get their oil analyzed after 8,000 miles or so. They scare me, but they do come up with some good data.
From scanning the site, they're big on a couple of things:
*Redline seems to help alot with lifter noise on startup. Some people mix that with the GC or other oils to get the optimum blend
*Oil viscosity selection should be dependent on the weather.
*There's a HUGE variance in oil filters...avoid FRAM
*They're big on extended changes as the holy grail (10,000 miles) and anyone who follows the dealer specs should have their oil analyzed.