Re: Unleaded Fuel and your Classic Alfa

[bearbvd@domain.elided (Greg Hermann)]

>This is a question aimed at our friends in the US (and Europe outside the
>UK).
>
>Here in the UK, leaded fuel will be unavailable from 1st January 2000. That
>is the official line, and comes about as part of the UK governments
>commitment to reducing global warming, pollution etc. However, there are
>still tens of thousands of cars on the road which cannot run on unleaded
>fuel, many of them 'classics'. Depending upon who you speak to, this problem
>will be overcome via the use of new fuels, additives etc which are already
>available in continental Europe. The effectivity of these additives, long
>term, may be in doubt, and the only real solution is to have harder valve
>seats inserted into your car's cylinder head.
>
>My perception of the US (and please forgive me if I'm wrong!) is that
>places like California, with it's strict emission control laws, must have
>outlawed leaded fuel a long time ago. If this is infact the case, what, if
>anything, did Afla owners do to overcome the potential problems. Was it a
>head rebuild? Have you used additives?
>
>I know that more recent models, like the 75/Milano, certainly in the UK,
>could run on either leaded or unleaded, but the none electronic ignition
>models would, I guess,  need timing adjustments at the very least.
>
>I was always intrigued with my Twin Spark 75, that while running leaded fuel
>the interior colour of the exhaust tail pipe was always that lovely coffee
>cream, indicating to me that combustion was spot on and the engine running
>correctly. However, tank up with unleaded and the colour soon changed to
>black, not exactly sooty, but hardly clean. There was no noticeable change
>in performance, but it always made me wonder about the perceived benefits of
>lead free fuel......
>
>The reason for asking is that I promised myself another Alfa for the
>Millennium, and I would like to know the score before I start looking around
>for a suitable car.
>
>Hope someone out there can help.
>
>Ciao,
>
>Ian
>
Hi Ian--

I am not aware of any Alfa engine over the past 45 years for which unleaded
fuel is a problem for the valves and seats which were used from the
factory. The seats which are used in aluminium heads are sufficiently hard
to stand up to the unleaded fuel, and I believe that Alfa valves (as made
by ATE or Livia, or whomever else), at least since the 101 days have had a
thin facing of stellite (an extremely hard and erosion resistant alloy of
cobalt, tungsten, and chromium) on their seat area.

The valve recession problem with unleaded fuels is pretty much confined to
engines with cast iron heads without either seat inserts or induction
hardened seats, and lower quality valves.

Regards, Greg

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