Ethyl

[JHertzman@xxxxxxx]

In AD7-397 Jon Herbert, in Ludgershall, Wilts, UK, wrote " Eh? I thought the
point of lead in fuel was as a lubricant, not anything to do with octane
ratings..." to which Ed Gibbs adds, in AD7-398 "That was my understanding
also.  It served as a lubricant for the valves. That's why most pre 70's
american cars don't have hardened steel valve seats in the engines and all mid
70's to current cars do.  Octane is needed to deal with knocking due to timing
right? Wouldn't that make lack of lead and addition of octane fairly
independent of each other?  How about Octane ratings in the 60's.  Were there
any?  I wasn't around so I can't say."  

In the UK, perhaps, and in the rest of Yurp, but in my desk dictionary
teraethyl lead is defined as "a heavy oily poisonous liquid used as an
antknock agent." (Didn't find it in the OED). The Britannica, after describing
how it is manufactured in the U.S.A., says "For use as an antidetonant, lead
tetraethyl (54.5%) is mixed with ethyline dibromide (36.4%) and Halowax oil
(9%) containing a distinctive red aniline dye" to make "ethyl fluid". Gas
stations when I was growing up had two pumps, one bearing the logo of the
Ethyl Corporation, (regardless of the brand of the gas) and the customer asked
for "regular" (also known as "white gas") or "ethyl" (also known as "high-
test" among the hi-falootin). I can't recall ever hearing about lubricating
properties, and I doubt if many drivers of the plainer sorts of cars ordered
the high-priced stuff. On the other hand, lead had a reputation for fouling
plugs and leaving deposits on valves, and my hot-rod brethren in the forties
preferred lead-free Amoco gas.

On Ed Gibbs' question whether there were octane ratings in the sixties, I
exhausted my meagre information resources in a posting in AD-7-218 about
Alfa's recommended fuels in the thirties; here I will just mention two
formulas for Shell-brand fuels called "Dynamin"; one, evidently for road use,
is ethyl alcohol 20%, benzol 30%, petrol 49%, castor oil 1%, giving an octane
rating of 95/100; the other, for track and circuit races, is ethyl alcohol
44%, methyl alcohol 44%, aviation petrol 12%, and castor oil 1% by weight,
giving an octane rating of 120/125. With the differing economics of petroleum-
rich and petroleum-poor regions, it seems quite possible that the US would
look to Ethyl for its antidetonation properties, while the countries where
alcohol mixes were economically competitive with imported gasoline might place
more value on some lubricating value in the lead compounds. 

Cordially,

John H.

Raleigh N.C.

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