Jarrid Gross (Yorba Linda) wrote:
>
> Larry wrote,
>
> >After a pollution tax was added to leaded petrol in Finland, leaded
> fuels
> >disappeared in few months. I have used 98/99 petrol with sodium
> additives
> >(these are added at oil refinery, and such petrol is available here at
> >every gas station). Now I have run my Mk 4 for three years with no
> problems
> >with exthause valves, seats or guides, neither elsewhere in the engine.
> >
> >I have heard, that about 1 to 5 % of old engine types can not use
> petrol
> >with sodium additives, and a valve-seat conversion must be done.
> Obviously
> >Rootes unit is among those 99 % lucky ones.
> >
> >Larry, Helsinki
>
> I'm not sure if the Alpine engine is really equiped to deal with no-lead
> fuels in the long run. Dont get me wrong here "no criticism", I really
> dont know.
>
> The valves are not stainless, as the newer engines are, and the valve
> giudes are cast iron.
>
> I've heard rumors that the seats are stellite, which should be OK for
> lead free fuels.
>
> Since none of us are really likely to put enough miles on one of these
> cars to really know if our motors are up to snuff, I doubt we will be
> certain for some time now.
>
> Anyone know what the stock seats are made of?
>
> Some will argue that the Petrochemical Society wanted to convince us
> that we really
> needed these lubricants in our fuel, when in reality we may not.
>
> Anyone have any data regarding the removal of of Tetra-Ethyl-Lead from
> fuel, and its effects upon the life of valves and seats?.
>
> Jarrid Gross
As I understand it (so take this for what you paid for it), for most of
our cars the removal of lead will not have any deleterious effects upon
our valves and seats, as conventional wisdom would have us believe.
Operating temperature is the key factor here, and the typical LBC
(running in the 160 to 190F range) should be perfectly safe. That temp
range leaves about a 15 degree cushion for those of us with poorly
calibrated temp. guages. That is, above about 205 things will start to
get messy (i.e., valves seats go bye-bye). I believe that the lead
that used to be in the fuel helped to raise this another 15 degrees or
so.
So, says you, why don't I just install stellite seats and be done with
the problem?
Because they are so hard that they will ruin your valves in 10K miles,
that's why, says I.
The moral: if you are running a normal street car which never sees
ridiculous temperatures then you can leave the stellite seats to the
racers.
As for the use of unleaded fuel, most of our cars were designed to run
on regular leaded fuel when new and that translates (in the U.S.) to
about the highest octane unleaded you can buy today (Sunoco 94 is the
highest in Connecticut that I can find). Does this mean that you HAVE
to run premium fuel? No but, if you don't, be darn sure to adjust your
timing to eliminate any pinging...you will lose some power but save an
engine.
'nuff said.
--Rick Hoefle 1964 Tiger B9470508 - HIS 1969 MGC - HERS
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