Peter Frederick wrote:
Actually, it turned out that removing lead from gasoline REDUCED valve
wear -- lead oxide is an abrasive, and far from collecting and making a
wear resistant surface, it was actively grinding on the valves and seat
as the valve operated.
Fine lead oxide particles made their way into the oil as well, nicely
"polishing" the oil carrying hone marks off the cylinder walls and
slowly reducing the size of crankshaft journals and wrist pins.
Engines last much longer without the lead than with it.
Not the same with sulfur containing compounds in diesel fuel, though --
they provide most of the lubrication qualities. I believer there are
now additives in the fuel to restore it's lubricating properties.
Peter
Sulfur provides NOTHING beneficial for a diesel engine. The residue from
the combustion of high (5000 ppm) or low (500 ppm) sulfur fuel is very
corrosive to engine surfaces and requires powerful additives and/or
frequent oil changes to neutralize. Removing sulfur however (using older
refining techniques) also removes other fuel fractions that provide
lubrication. If it's not replaced, the resulting fuel after the sulfur
is removed has lower lubricity. If the lubricity is restored, the
resulting fuel is much superior to the low sulfur (500 ppm) diesel.
Marshall
--
Marshall Booth Ph.D.
Ass't Prof. (ret.)
Univ of Pittsburgh School of Medicine
[EMAIL PROTECTED]
