S&S Oil Control Valve The factory oil control valve on all oil cooled M8 engines regulates the amount of oil flowing to the oil cooler/heads. The stock assembly includes a check ball retainer that is formed steel. Over time, this retainer can fatigue and break, causing chips to flow through the oil system, back into the tank and can causing significant damage along the way. Features: The factory oil control valve on all oil cooled M8 engines regulates the amount of oil flowing to the oil cooler/heads The stock assembly includes a check ball retainer that is formed steel Easy to Install