Originally Posted By: 99
Originally Posted By: Gary Allan
These are typically engines with higher spring rates. If you've got normal spring rates ...you don't have to worry about it.
No, if I think I know what you are referring to. Flat tappet cams/lifters need ZDDP to provide a buffer between direct metal to metal contact irregardless of spring rate. Flat tappet cams/lifters basic operating principle is direct contact, so you can see why a pressure additive is so critical to the life of these parts. This has been a very hot topic in the hot rod community and EVERY major cam manufacturer (Crane, Comp, Erson, Isky, Lunati, etc) say to use a oil with elevated levels of ZDDP in it if you are going to run a flat tappet cam. Call them and they'll tell you personally. In a perfect world every engine would use a roller cam, but that's not the case and hence the ZDDP issue.
Oh ..you mean that even the GM 3.1 V6 ..that SWRI uses to certify the GF4 SM oils is being destroyed by the same oils that they're certifying?? (admittedly, they do, more or less, destroy them ..but you get the point)
Every magor cam man isn't selling aftermarket STOCK cams. Where are the flat tappet failures of the OEM engines? I just haven't seen them. This leads me to believe that either the cams aren't manufactured correctly (not likely) or they're under higher spring rates (VERY LIKELY) ..or the people installing them aren't doing proper cam wear in (EXTREMELY LIKELY) ..or all of the above (minus the lame manufacturing).
How many stock engines, over history, have had cam FAILURES due to too long an OCI that surely would have depleted the zddp level to useless? None that I'm aware of (although there are probably a few) ..now cam "degradation"? ..sure ..but "wiping lobes"?? Nope. The notion just isn't supported in real world observations.
