Flat-Tappet and Camshaft Lobe Lubrication

This is the Technical Service Bulletin relating to AMSOIL’s main high zinc and ZDDP oils as discussed on a recent video posted on YouTube.


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


Flat-tappet camshafts undergo extreme pressures and
loads, requiring a motor oil fortified with anti-wear additives
to provide premium protection. The severity of higher
spring pressure in racing engines also creates the need for
additional wear protection.
Phosphorus levels in motor oil have been reduced to preserve
catalytic converter life, but concerns have risen that
oils containing lower levels of zinc/phosphorus could provide
insuffi cient protection in the high-pressure areas of
flat-tappet 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. AMSOIL Break-In Oil
is specifi cally formulated with zinc and phosphorus antiwear
additives to protect cam lobes, lifters and rockers
during the critical break-in period. Break-in duration varies
between engines and should follow the engine builder’s
or manufacturer’s recommendations. Once the break-in
phase is completed, AMSOIL synthetic motor oils, which
are formulated with high levels of zinc and phosphorus,
provide premium protection for flat-tappet cams.

Read more and see the list and Zinc levels of subsequent AMSOIL products…

Oils for Classic Cars