Dennis:
The newer motors use roller cams, so the old concerns about
breaking in the
cam do not apply in these cases. As for the reduced oil consumption,
valve stem
seals are now 'de rigueur' so that path for oil loss has been closed
off. The
pistons and rings have also been redesigned for reduced oil consumption.
All of
this is to reduce emissions.
Add to all of this the improved materials and tolerances and you
have much
lower emissions and oil consumption. Another plus is unleaded gasoline,
which
eliminates deposits on valves and keeps the engines running at peak tune
for
much longer.
Another improvement are the newer motor oils. Synthetics are the
king,
but even the regular petroleum based oils are much better, with improved
lubricity and better detergents. The manufacturers have also learned
that
the majority of wear occurs at startup, and so are recommending lighter
oils
now that circulate more quickly and reduce startup wear.
Many of these improvements are available for our sixes, such
as oil seals, improved oils, unleaded gas, etc. Many of them require
internal
work in the motor to realize the benefits, however =:-(
Vance
P.S. Was the "coating" your friend referred to "Parkerizing"? If
so
this is an inexpensive surface hardening and corrosion inhibiter
process. It as
been around forever.
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Dennis Costello
Sent: October 20, 2005 8:09 AM
To: Six Pack
Subject: Synthetic oil and break-in
I see the reference again, and the curious question that has been in my
head
for some time is this: In the old days (60's) when I read the car mags,
the
crosshatched cylinder was a fact, and break-in a usual process. Even
today,
on rebuilds, the new cam must be bedded in at a suitable RPM in order to
ensure lubrication. The '61 Ford I had rebuilt in high school always
used
about a quart of oil every 1,000 miles. I was told that was a good
sign, as
the rings and cylinder walls were being lubricated. So, how is it that
today, with emissions as they are, and the oil consumption being held to
a
minimum as a result, that engines don't seem to use drop from new, and
there
is no run-in of the cam? A friend in the agricultural diesel business
says
the cams from the factory are coated (brain dead, can't remember what it
is). So, better machining for a rounder cylinder, better materials for
reduced wear, er what?
old minds want to know!
-Dennis
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