AMSOIL has updated a technical service bulletin on Flat Tappet and Camshaft Lobe Lubrication and the importance of using a motor oil containing generous amounts of zinc and phosphorus. Owners of older or high-performance engines with flat tappet camshafts are always watching for motor oils with sufficiently high levels of zinc dialkyldithiophosphate (ZDDP). ZDDP contains both zinc and phosphorus components. AMSOIL offers a multitude of motor oils at most every viscosity grade which contain suitable zinc/phosphorus content for flat tappet cam protection. This service bulletin lists each product and their zinc and phosphorus levels.