[net.cycle] leaded gas in aluminum engines

srneely@watcgl.UUCP (Shawn Neely) (08/21/85)

Recently someone responded to a request for opinions on '82 Sabres.
In his posting, he mentioned that regular leaded gas is bad for
aluminum engines.  I have never heard this, and my owners manual and
shop manual for my Sabre make no mention of this hazard.
Does anyone know anything about this? Genuine danger or old wives' tale?

darryl@ISM780.UUCP (08/25/85)

Gee, both my aluminum cylindered BMW's were/are quite happy drinking leaded
regular...  The first went 56k, the second now has 7k miles.

	    --Darryl Richman, INTERACTIVE Systems Corp.
	    ...!cca!ima!ism780!darryl
	    The views expressed above are my opinions only.

animal@ihlpa.UUCP (D. Starr) (08/26/85)

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> Recently someone responded to a request for opinions on '82 Sabres.
> In his posting, he mentioned that regular leaded gas is bad for
> aluminum engines.  I have never heard this, and my owners manual and
> shop manual for my Sabre make no mention of this hazard.
> Does anyone know anything about this? Genuine danger or old wives' tale?

I think we have a case of confusion here.  It is true that unleaded gas
(which is what the original article asked about, I think) can damage
some motorcycle engines--but not an '82 Sabre.  It is also true that 
certain gasoline additives (alcohols) which are fairly commonly used
these days can trash out any motorcycle engine.  And, yes, you can turn
the aluminum in your engine into cottage cheese--but not by your choice
of gas.

Older bikes, notably of European and American descent (Triumphs, old
BMWs and Harleys), were designed for leaded gas and may suffer rapid
valve and seat wear if run on unleaded.  Japanese bikes from the mid-70s
on do not have this problem, apparently because the Japanese manufacturers
borrowed the valve and seat technology from their automotive divisions
(remember, the EPA effectively mandated no-lead for cars in 1975).  This
is becoming a crusade for older bike owners and collectors of classics,
because the EPA now wants to ban leaded gas outright.  As for the Sabre,
you're probably best off running unleaded premium because of its high
octane and the longer plug life you can expect with it (plugs often die
of lead fouling in engines run on regular).

What you *should* worry about is alcohol, particularly methanol (wood 
alcohol, the stuff your Uncle Fred the moonshiner went blind drinking).
Both are being added to gasoline to raise octane and stretch it out
(ethanol--grain alcohol--because it's subsidized in the farming states,
methanol because it's cheaply made from natural gas).  Both have the
habit of absorbing water and then dropping out of solution into the
bottom of your fuel tank, creating a rusty surprise when you hit
reserve.  Methanol is also a solvent--it will eat rubber seals and carb
parts, dissolve paint and some protective tank liners, and (get this!)
if left in a carbureter over the winter can actually eat the pot metal
carb body!  It's almost impossible to avoid alcoholic (ethanol) gas
in the Midwestern U. S. because of the subsidy.  My solution to the
water-absorption and separation problems is to ride more, get the gas
through the engine before it has time to separate.  Methanol I avoid
by smell--it's got a very noticeable reek to it (uncork a can of gas-line
antifreeze sometime for a sample), and if I smell that at the pump I
go somewhere else.  Luckily, it's not too common here because natural
gas isn't produced in Illinois (It's big in Pennsylvania, though).

As for turning your engine into industrial waste, you can melt down an
aluminum engine very easily by using the wrong water in the cooling
system.  Minerals and stuff in tap water will rapidly corrode the
aluminum block and clog the radiator.  Repeat after me: "I will use
only distilled water in my water-cooled motorcycle."  (along with
the correct anti-freeze, of course).

So for the '82 Sabre--name-brand unleaded premium in the gas tank and
distilled water in the radiator, and you'll have a long and happy
life together.