Todd Byers said:
> In my 1962 MGA the previous owner always ran with premium unleaded
> fuel so I continued the practice with no additives. I don't know if
> that was the entire problem, but it ate a valve seat once so I
> replaced the head (again with original seats) and fairly promptly
> burned a valve. Since then I have had hardened bits put in, but in
> retrospect I would have probably sought out leaded fuel.
Valves burn from lean running. A burnt valve has a really interesting
curving pie shaped piece cut out of it. I've always admired the shape
of the burnt out part of a valve. I suspect that some simple three-
dimensional equation with echoes in the natural world would describe its
curves.
I can't describe the damage to a valve from using unleaded gas because
I've never seen any but I've heard that it only causes a slight loss in
compression. However, I have seen the damage caused by a hardened valve
seat that's come loose. This is not that uncommon with hardened valve
seats and a loose valve seat will cause _much_ more damage than unleaded
gas.
I've put 150K miles on the perfectly stock head of my '67 B and never had
any problem using premium unleaded. Don't worry, be happy.
Denise Thorpe
thorpe@kegs.saic.com
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