<VV> lead additive

[kenpepke at juno.com]

Seth said, in part ...

>Those additives are needed for the 60's  
cars with the fore-mentioned valve seat recession problems. The lead acts  as 
a cushion for the valve when returning to the softer cast iron seats.<
--------------------------------

Many years ago Buick did extensive testing regarding the use of unleaded fuel
causing recession of the valves in a cast iron cylinder head.  Their tests included
hundreds of hours of normal to hard use simulation on dynamometers.

Someone there wrote an SAE paper (sorry I can't find my copy) that showed there
was no problem with recessing of valves until after many, many hours of hard racing.
They concluded there would be no noticeable problem associated with unleaded gas
use in street driven cars as long as the engine octane requirements were met.

Ken Pepke