Stamped steel rocker arms are common on budget crate engines, and many race classes require the use of stamped steel rockers. Because they do not feature a roller bearing pivot, stamped steel rocker arms generate more friction than performance-oriented roller rockers.
That’s why proper break-in of stamped steel rockers is a must to maximize the lifespan of the rockers.
Start by pre-lubing the inside cup of the rocker arm with engine assembly grease. After installing the rockers arms and setting the valve lash, pour break-in oil, such as Driven’s BR Break-In Oil, over the rocker arm assembly (16 oz per side on V8 or V6 engines). Upon start-up, bring the engine speed up to 2,800 rpm and hold steady for 10 minutes. After 10 minutes, shut down the engine, and allow the engine to cool down for 10 minutes. Restart the engine, and bring the engine speed back to 2,800 rpm for 10 more minutes. The rocker arms are now properly broken-in.
If the engine features flat-tappet lifters, you should follow the same procedure as above. However, it is recommended that you use a synthetic motor oil. Conventional motor oils, even high zinc racing oils, do not provide the required friction reduction needed to properly protect stamped steel rocker arms. Endurance testing conducted by Driven Racing Oil shows that synthetic motor oil reduces oil temperature, wear, and friction (see chart below).
If your next factory engine build or budget upgrade includes stamped steel rockers, you can avoid failures and extend the life of your engine by following the simple steps above.
16 oz break-in lube per side? At least 50% of that will run down into the oil pan.
Which component has the most critical break-in factor ? camshaft, or valve springs ? I will do 1/2 hr at a minimum of 2K variable rpm, a small cool-down cycle of 3-5min. and not restart for 24hrs, for the sake of the valve springs, along with the initial oil & filter change, other opinions are important.
Proper break-in of each is critical, especially as it relates to flat tappet cams. We’ve covered that topic here…and here’s a link to great article on spring break-in: http://www.compcams.com/Pages/415/truth-about-valve-springs.aspx