break in oils

[VintageMusclecar]

One other thing I forgot to mention...

Another potential issue that can contribute to cam/lifter failure is a tight or dirty lifter bore. A flat tappet lifter absolutely must be able to rotate freely in its bore...if it can't spin, it will go flat.

As I've mentioned before, as a matter of SOP, I now run a small ball hone through the lifter bores of every engine I build just to make sure there's no varnish or "boogers" left behind after the block has been cleaned.

Afterwards, during mock-up I test-fit the lifters in their bores to make sure they all slide right in and will spin with no effort. You'd be surprised at how many "snug" lifter bores I've encountered even after the block has been cleaned.

Eric