re: Lead lubricates SPICA?

[Dana Loomis <dloomis@domain.elided>]

>Having put 2000 miles on my 73 GTV with plain old unleaded, you might 
>imagine my dismay at the lead substitute post...
>Have i caused irrevocable harm? I was under the impression that the valve 
>seats were already hardened by '73, but was unaware of the SPICA issue. 

This is one of those threads that never die--like spark plugs and oil
filters.  The best answer to the question may be in your owner's manual.
The manual for my '72 GTV says the car can be run on either leaded or
unleaded fuel; I'd guess it's the same for your '73.

These dire stories about the lubricating properties of lead keep
circulating, but it's unclear how lead in the circulating gasoline stream
is supposed to lubricate anything.  The lubricating effect on the valves
results from the combustion process, which produces lead residues, some of
which accumulate on the valves and seats (the rest goes out the tailpipe
and accumulates in people). 

Dana Loomis

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