Unleaded gasoline has been the norm in the US since the mid-late 1970's.
Three grades available in most places: 87, 89, 93(94) octanes. All
unleaded.
Leaded fuel cannot legally be used in any car driven on public roads.
Lead additive served two basic functions: lubrication of the valves/seats
and as an
octane boost.
The solution to the former is hardened valve seats. The solution to the
later is
octane additive and/or racing fuel ( not available for street use).
Having said that, what follows are some personel experiences.
I vintage race a 1952 TD. Until last summer the engine was completely
stock.
I used 87 octane, unleaded fuel. Ran 30 events over 5 years. Last spring
I
ruined a bearing necessitating an engine re-build. When taken apart the
valves
and seats showed almost no wear.
I also vintage race a 1930's Model A Ford engined dirt track car. The
engine is a
1931. Didn't have lead in the fuel in those days and with a stock
compression
raito of something like 4.5/1, octane wasn't a problem. Needless to say I
don't
have any problems with modern unleaded even though the engine now has a
whopping 5.6/1 compression.
Two engine builders that I know who rebuild old/antique/race motors
say about the same thing. Unleaded may cause more rapid wear on valves
and
seats but given that most older/classic cars are driven limited amounts,
the wear
won't be noticable for many, many years. They recommend that you use
hardened
valve seats if/when you need to do repairs but don't rush out and spend
the money
until necessary.
Bottom line, I agree with others that the panic is mostly hype, either by
the uninformed
or those with a vested interest.
Safety Fast
Dick
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