Oh, heck, I can't resist...
In the UK a few (5?) years ago they phased out leaded (4- star) and a couple of
classic mags did tests on cars with UNHARDENED seats.
They were testing to find out if the additives really worked. I seem to
remember that most of the additives worked somewhat, but some were better than
others, and none was nearly as good as tetraethyl lead!
Given that we've all been running on unleaded for years now, if you haven't had
a problem yet, you probably won't. Most aluminum heads had hardened seats and
valves... I can't speak for the iron ones...
My dad's Farmalls all have soft seats, and the tractor that I baled and plowed
with 25 years ago hasn't had a valve seat recession problem yet...
Toby
> The regular/leaded/additive topic surfaces with
> some regularity on the list. Which is OK.
>
> I use a lead substitute in the fuel for my 1949
> Allis-Chalmers (low-octane no-lead)
> Does anybody know of definitive, impartial
> tests involving valve seats on old engines and
> recent types of gasoline?
>
> --Bob Keen
> 68 1600
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