STANDARDExcellent For Preventing Cam & Lifter Wear On Non-Roller Cam Engines Ideal Substitute For GM's E.O.S. (Engine Oil Supplement) ZDDP (Zinc Dialkyl Dithiophosphate) Brings Current SM Oil Catergory Back To SF Specifications For EP (Extreme Pressure) Required For All Engines Prior To OBD Vehicles With Flat Tappet Cams 4 Oz. Bottle It's a well known fact among engine rebuilders and mechanics, older engines especially performance engines prior to 1988, that have flat tappet setups required a well-known oil additive called ZDDP. The additive is made up of phosphorous, sulfur and zinc. By using the proper amount of these three chemicals, it makes ZDDP. This additive has been the most effective extreme pressure additive found in quality motor oil for almost 70 years. ZDDP is a surface modifier. It modifies bearing and journal surface characteristics to prevent metal-to-metal contact. Under the right conditions of heat and pressure, the zinc in the ZDDP actually plates over the contact surface and provides a sacrificial coating. As it breaks down, it dissipates back into the oil solution and remains in suspension until the right conditions arise and the process starts over again. This reduces the tendency of parts to scuff and gall under heavy-loaded boundary lubrication situations.
