I just changed the mineral oil after 25 hours with new Superior Millenium
cylinders (standard cast). The rings are broken in and consumption has
stabilized. My analysis came back with high Lead, Chrome, and Nickel
levels which Superior says it normal with these cylinders. However, the
analysis also came back with very high levels of Tin (13.6 vs 1.2 before
the new cylinders). Aviation Laboratories said on the analysis sheet that
this could be caused by bearing wear. My A&P said the lower half of the
engine looked good when he installed the Cylinders. Superior says the Tin
shouldn't be in there from breaking in the cylinders. They suggest retesting
in another 25 hours.

Anyone know what may be going on with the Tin? Thanks in advance....


Trip Farmer
N8501N
PA28-235