Your new engine will require some break-in (see sidebar). But first, you need to add some additives to make sure the flat tappet cam doesn’t immediately flatten itself out. The cam in the engine is a Comp Cams part, so we decided to use Comp’s break-in additive to keep it happy. In 2005 the EPA mandated lower levels of zinc and phosphorous in oils to reduce emissions. For roller lifter engines there was no change. For our flat tappet engines this made a huge difference. Comp also now offers break-in oil with the additives already mixed in.