Grandson Ben and I built up an engine for the Yellow Peril, a 1973 145E, about
a year ago. We got distracted with FI problems and temporarily abandoned the
project last fall. We picked it up last spring and through help from Mark
in Hutch and some of you folks and a lot of persistence, finally got it running.
It is stock bore, stock pistons, bore honed enough to give a pattern, and new
std size rings. Up till this weekend my guess is it had maybe 50-75 miles on
it, mostly around town here and pretty low speed. This weekend I drove it about
250 miles, mostly on the highway at speeds between 50 and 70 mph. Seems to
be running pretty well other than the idle speed seems to vary some.
I am using Phillips TropArtic motor oil, which I consider to be one of the
best petroleum based oils on the market, although I may be prejudiced.
At 250 miles the oil looks good and clean.

In the old days they used to consider the first 500 miles on an engine a
breakin period and advised an oil change at that point. Is this the
conventional wisdom these days?
--
George Downs Bartlesville, Heart of the USA!