[Formulajones]

Ive never in my lifetime performed a flat tappet break in with a roller cam and I run a bunch of roller cams here.

I do however use break in oil because there are a lot of other high pressure and high wear areas in an engine that have to get happy with each other. Like pushrods, rocker arms, piston rings, piston skirts, etc.... the only difference with a roller is I don't run the engine at 2000+ rpm for 20-30 minutes upon first fire up. Some break in oils also help ring seating which is important

I will however as I explained dump the oil for fresh break in and continue making sure I keep clean oil in it with frequent changes for the first 1000 miles or so. Give the engine it's best chance, after all these things aren't cheap to build so a couple hundred bucks in oil is nothing.