Jeff,
In the UK we are going through the trauma of the withdrawal from sale of
leaded fuel right now, so there is a lot of discussion and information
going around about what to do.
Basically there seem to be 3 options:
1. Just put unleaded in your tank, and retard the timing a little to
avoid pinking. After many years of running on leaded there will be an
amount of lead absorbed into the surface of the metal, and this will
provide limited protection against valve recession (the real killer with
unleaded fuel in cars not designed for it). This may be sufficient if
you do low mileage, and drive gently (neither of which I would advocate,
as someone who does 16,000 hard miles a year in my Spit 1500!), but
eventually the valve seats will wear and you will have to have your
cylinder head re-conditioned and new valve seats and valves fitted.
2. Get your cylinder head converted right away, rather than waiting for
the damage to occur and then getting it done - best option for the long
term, and not too expensive (at least in the UK, no idea about the US).
3. Use an additive in your unleaded petrol. These are available in car
part stores in the UK, and presumably in the US, plus we get it
available pre-mixed in what is called LRP (lead replacement petrol) at
the pumps - not a conveniance you will have! The additive is simply a
small bottle, add one to your tank each time you fill up, and it
contains a (non-lead) chemical that gives similar protection to lead,
although not quite as good. Some also contain an octane booster, so you
do not even need to retard your ignition.
The FBHVC (Federation of British Historic Vehicle Clubs), an umbrella
organisation for all classic car clubs in the UK, did tests on around 12
different additives at the beginning of this year, and found just 4 that
they could recommend - if you want to know which these are I can dig out
the info.
Beware of anyone trying to sell you any sort of 'catalyst' or device
that you fit in the fuel line, ususally containing tin pellets, that
claim to allow you to use unleaded fuel with no problems - the FBHVC
tested several of these and could not recommend any of these.
Personally I doubt these are anything more than a placebo.
I hope this helps, and doesn't just make the issue more clouded!
Richard Gosling
Daffy (Inca yellow '78 Spit 1500)
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