AMSOIL and Flat Tappet and Camshaft Lubrication

Provide facts outlining lubrication requirements of flat tappet camshaft engines and the importance of higher levels of zinc and phosphorus.

Flat tappet camshafts undergo extreme pressure and loads, thus requiring an engine oil that is fortified with antiwear additives to provide premium protection. The severity of higher spring pressure in racing engines also creates the need for additional wear protection.

To preserve catalytic converter life, phosphorus levels in motor oil have been reduced. Concerns have risen that oils containing lower levels of zinc/phosphorus could provide insufficient protection in high-pressure areas of flat tappets and camshaft lobes found in many older and high performance engines.

The most commonly used anti-wear additive in motor oils is zinc dialkyldithiophosphate (ZDDP). ZDDP contains both zinc and phosphorus components working together to provide anti-wear protection, and is most important during cam “break-in” procedures. Proper break-in lubes should be used during the break-in phase for all new or rebuilt engines with fl at tappets. These lubricants provide the extra protection required to reduce wear at the point of contact during break-in and help the fl at tappet face properly mate with the cam lobe. Once the break-in phase is completed, AMSOIL motor oils, which are formulated with high levels of zinc and phosphorus, will provide premium protection to flat tappet cams.

The American Petroleum Institute (API) and International Lubricants Standards Approval Committee (ILSAC) have mandated the reduction of phosphorus to extend catalytic converter life. However, reducing the level of ZDDP can compromise protection to engine components, most notably in fl at tappet camshafts. Current API SN and ILSAC GF-5 specifications for gasoline engines have maximum and minimum phosphorus levels of 800 ppm and 600 ppm, respectively, for SAE 0W-20, SAE 5W-20, SAE 0W-30, SAE 5W-30 and SAE 10W-30 motor oils.

All engines, especially high-performance modified engines, benefit from oils with superior film strength and antiwear properties. The flat tappet/camshaft lobe interface is the one area in an engine that has extreme contact load. Since this load increases significantly when non-stock, high-pressure valve springs are employed, the use of properly formulated motor oils is extremely important to reduce wear and extend fl at tappet/camshaft life.

AMSOIL recommends motor oils containing high levels of zinc/phosphorus for superior protection. The following tables list many of the AMSOIL synthetic motor oils that are formulated with high levels of anti-wear additives: