The shop Z06 is on the mend from recent piston surgery, and I bought some Mobil1 0W-40 motor oil to fill up the dry sump tank for its initial fire. GM recommends 5W-30 Mobil1 and every LS7 leaves the factory filled with it, and I like the 0W-40 only because it has more zinc, and it is preferred oil in my crowd at the local tracks. I mentioned all that to Dave Crume (of Crume Racing Engines), who built the short-block, and he cringed. He told me to use Joe Gibbs break-in oil for a couple of hours, then switch to a quality non-synthetic oil, and then to a synthetic oil at 500-1000 miles. He said the engine wouldn’t break in properly unless I did that.
Call me skeptical. Continue reading