Again Fryfly is mis/ill informed and relating things he knows little about. .

We use ASHLESS oils in our engines. . oils containing NO SOOT. this is because an "Ash" oil leaves behind deposits inside the combustion chambers that very quickly form carbon, buildup, and can cause pre-ignition or detonation. EVERY model engine manufacturer/supplier says to use ASHLESS oils.

Our engines have TIGHT clearances in the bores, whereas NASCAR engines (I used to build hi-po motors and live next to a NASCAR race shop) have very loose clearances in their piston-bore area. . usualy on the order of .0025-.003" at least, and as much as .005" in some cases. What do the NASCAR teams run?? 50-60 weight RACING oil, petroleum based for the most part but some synthetics, and they cool it with a cooler and use dry-sump systems operating at over 100 PSI at 7,000+ rpm. EVERY NASCAR engine is test run in on a Dyno or engine stand for 8-10 hours before it ever gets inside an engine compartment. There are no green bores, fresh ring facings or unbroken in engines in the car haulers and pits at a NASCAR race. how are the engiens broken in? A very methodical run-in is done, with 5-6 periods of running, to check the motors out and break them in and let them heat cycle a few times to let things settle out.

It's nice to be able to cut and paste selected information gleaned from a website so that everyone else can read it, but it also shows that the recommendations concerning proper break-in of our engines (as suggested by the manufacturers) , that is, to use 32:1 - 50:1 ashless petroleum oil for 8-10 gallons for proper break-in, then switch to synthetic after that, is exactly what the SAE recommends for this type of activity.

It kind of makes you wonder if these "suppliers" of engines, rather than people who actually BUILD them for a living, know what they are doing. Anyone can be a salesman, but few KNOW their product well enough to be able to tell you exactly WHY it does what it does, and how best to get the most out of THEIR design. Thanks, I'll listen to the people who designed and built the motors I use . . .rather than some wannabe importer who will say whatever it takes to make a sale.