In reply to a message from Jack Hollibaugh sent Sat 17 Sep 2011:
Interesting thread
A subject that I have been interested in for the past 50 years.
What I noticed is that over the years engine cleanliness has
changed drastically. All in all they are much cleaner today than
at any other time I can remember. To a very large extent the
engines are cleaner because of the oil that we using these days is
simply better.
The additive package is better, particularly the additive that acts
as an antioxidant . It�s the antioxidant that prevents the
formation of sludge. But when the additive wares out, and it
does, the sludge will be start to grow again. A good reason to
change oil.
The API certifications change about every two or three years . Most
times in response to changes in engine technology as well as
changes in EPA requirements. A few years ago it was common to
have a bunch of ZDDP as an additive. It was a great high pressure,
anti scuffing additive. Frankly without it engines with flat
lifters and high valve spring pressures are living on borrowed
time. But the EPA found out that the ZDDP was reducing the use
full life of our catalytic converters, so every two or three years
since the late 80�s the API has come out with a new specification
that the API responds to by reducing the amount of ZDDP in the
latest oil spec… That started when we had SH oils, still the
best for motorcycles and muscle car engines. As far as I know
Oilzum is the only company making an SH oil these days. Today SN
is the 2011 spec. It�s focus is to improve gas millage, reduce
pollution, and one of the new additives that ha s been added is
an additive to protect engine from the use of E-85 gasoline.
In addition to the API periodically changing our oils, we have
this incredible collection of petroleum based oils that according
to our courts can call themselves 100% Synthetics. Hog wash.
These synthetic wannabes s have gone through an additional
Chevron Iso De-Waxing Process that has reduced the amount of wax
in the oil from a full dinner candle to � a dinner candle. That�s
nice!
Real synthetics don�t have any wax! In addition the wannabes
have also been refined further to increase their natural viscosity
to 120. That�s a good thing. It allows the additive package to
reduce the amount of Viscosity Index Improvers.
So we get to the question where does the crud in the engine come
from.
I have been doing leak down tests on my own engines for the past
20 years. What I have found is that if the engine isn�t sealing
itself very well, it�s because the top compression rings cannot
move freely in their ring groves … What�s should happen; as
the ignited gasses in the combustion chamber are expanding, a
small amount of them sneak between the piston and the cylinder
wall, until they get to the compression ring. Then they travel
across the top surface of the ring and into the space behind the
ring pushing the ring out against the cylinder wall, sealing the
engine preventing the products of combustion from getting into the
crank case.
So if you have any blow by, the chances are that you have been
using good old fashioned petroleum oil for a long time and your top
ring is stuck in the ash from burned viscosity Index Improvers.
Real synthetic oil doesn�t have any VII�s. And it doesn�t have
any wax. So the ash left from burning
VII �s doesn�t exist and the wax that forms sludge when the
antioxidents wear out doesn�t exist either.
The real synthetics made from esters that make up what they call
group V stocks, also have a natural solvent action that dissolves
varnish ,and coaked oils, and sludge. Using them will, over time,
eventually, get rid of the stuff that�s plugging up the top ring
land and will return the engine to leak down tests that will be
better than when the engine was new. Performance gets better,
gas millage gets better, the engine will last longer, and the oil
change interval will increase dramatically if you have a
professional oil analysis done once a year you will see gradual
dramatic improvements in all of the things they measure
particularly the additives will be in great shape even after 20,000
miles. After it�s cleaned up. But it won�t happen immediately
you will need to be patient while your oil does the wash.
Would I use Seafoam, not even in my lawnmower.
Would I use an oil that is basically the same as it was 50 years
ago, not even in my lawn mower.
I wouldn�t use the Petroleum / Synthetics either, even though they
are much much better than the plain old Group III Stock based oils
that still represent over 85% of the motor oil being sold.
Regards
Pete–
SpeedyPAL 1995 XJR
Milford / OH, United States
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) OEM Solex carburetor while it idled. And yes, lot of white smoke out the exhaust until the engine almost stalled out 
… Let it idle awhile longer and then resumed pouring, back and forth like that, until the bottle was empty. I admit for that type of engine (i.e. carbureted) it did seem to make a big difference in her performance afterwards, esp. in regard to maintaining smooth idles. 