In a message dated 5/24/11 12:04:40 AM, coudesluijs at chello.nl writes:
> I have never used "running in" oil but always primed the rebuild engines
> turning over by hand first and then on the starter without plugs until
> oil pressure was shown.
>
What is called "running-in oil" is simply a good high-grade, heavy-weight
oil with a guaranteed high amount of ZDDP additive. Torco oil is one good
example. In Europe, you may never have had the problem we had here for several
years, when the oil companies were removing ZDDP from all of their regular
oils and one of the consequences was that engine rebuilders were encountering
problems with new cams being destroyed during the critical first 15 minutes
of operation of the new engine, when there was no Zinc to bond with the
Molybdenum to fill in the microcavities on the surface of the cam lobes. With
more over-the-counter oils in the 15/40 and 20/50 range now with ZDDP
additive again, it seems to be less of a problem, but the rebuilders I know
still
use the high-quality oil during that critical first hour or so of engine
operation.
Gary
|