Note: never use synthetics for engine break-in... john Re: New engine break-in Posted by: eastvns Date: Wed Aug 9, 2006 8:59 am (PDT) How far has the technical side of this group dropped to post such misleading information about something as simple as engine break-in? Break-in demands 1800+ rpm for a minimum of 20-minutes - for flat tappet cam. The rpm should be changed from 1800 to 3000 during cam break-in to alter the load on the lifters (the dynamic load changes with rpm and allows the lifters to rotate at different speeds to prevent a wear pattern wave on the lifter and cam lobe faces). The varied rpm change also varies the splash oiling of the wrist-pins and rocker arms (and allows the valve spring rotators to spin the valves & springs so the exhaust valves seat properly and the springs do not hammer through the shims). Extended duration idle engine speed will not splash lubricate the wrist-pins or lower the dynamic load on the valve train (it is a recipe for trouble on initial break-in). Motor Oil has been regulated by the federal government to eliminate almost all of the zinc (ZZDP) and other surface hardening lubricant additive in the last two years. These metal based additives can damage a catalytic converter during the federal 50,000 mile EPA warranty requirement (and are not needed with roller lifter cam followers). These additives are no longer present in the current SAE grade motor oil, the current SAE spec oil provides no break-in anti-wear protection for sliding lifter surfaces (for flat tappet cams and lifters). This lack of additive is why the number of cam failures have been extremely high in the last two years. The anti-wear additives still remain in Diesel grade motor oils (through 2007). Break-in should be performed with diesel specification oil (Shell Rotella or other diesel specification oil). Change the filter at 100 miles or the first two hours of operation. Change the oil at 500 miles or the five hours of operation. Change the oil as often as you want, but use a grade of oil (or an additive package) that is designed for the style of cam and lifter used in the engine (diesel spec. oil, some off-road spec. racing oils, or use an oil additive with ZZDP). HTH? Happy Trails! Ed A. Stevens