On Thu, 13 Jun 1996 MGBCHRIS@aol.com wrote:
> Lead was added to fuel for one reason only - it serves as a "cushion" or
> lubricant for the valve to valve seat. Older vehicles had valve and seat
> materials that were damaged easily by the combination of high temperatures,
> and the pounding of closing under high forces thousands of times per minute.
> Leaded fuel will not make a poor running engine run better by itself,
> although it may reduce wear on the valves over time.
I believe tetraethyl lead was added to fuel to increase its octane rating,
not to lubricate valves. I doubt anyone realized it lubricated valves
until well after it began to be used. In fact, premium gas used to be
called "ethyl" as in, "fill it up with ethyl." Adding lead to gas may
improve an engine's running, if the problem is preignition.
Ray Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8910
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