[modern] valve job & rf gas, old wife's tales?

BiggySmalls said:

  • my machinist says he has seen allot of his burnt
    valve stuff
    with the reformulated oxygenated gas …

This is an old wives tale, and there are lots of other old wives tales
circulating about oxygenated gasoline (some of the others stories blame
oxygenated gasoline for engine fires and broken hoses).

Reformulated gas has 10 % alcohol, alcohol has half the heat(BTU)

content. Fuel injected and feed back carburetors will compensate for this.
The problem comes in with older cars with carburetors that fix the air/fuel
ratio. The engine then runs lean. The result is many times a burnt valve. A
car from the 70’s this is more acute because they were leaned out more for
emissions. Also a car of this age (25 years) will have flexible fuel lines
not designed for this new “brew” of gasoline, that should probably be
replaced just because they are old.
Also a interesting side note a major ($300m sales) grain supplier
was very involved in the lobbying of alcohol added fuels, several years ago.
Follow the dollar.
I avoid reformulated gas when ever possible. All of my small air
cooled engines, get gas from an area that does not have alcohol. This site
has lots of info on gasoline
http://www.cs.ruu.nl/wais/html/na-dir/autos/gasoline-faq/part1.html

Roger Hajny
75 Chrysler
90 sovereign
93 vdp
2 minivansSubject: [modern] oxygenated gas (was Valve job)