The Dickinson press., 1912-01-13
FUEL FOR AN ENGINE
Other Things to Consider Than
Starting and Stopping.
Few People Realize Importance Of eup.
! plying Air and Gasoline In q Def.
mite Proportion - carbureter
Does the Mixing.
(By c. L. GUINNESS Professor Of Engi-
neering. North Dakota Agricultural

(By c. L. GUINNESS Professor Of Engi-
'neering. North Dakota Agricultural
C0llege.)
When q man buys q gasoline engine
the first problem that confronts him
is. how to start and stop it. These
things are usually learned In a very
short time through the assistance of
the expert who delivers the engine or
the small book Of instruction found in
the tool box. The gasoline engine op-
orator should, however, not be salts
fed with his engineering II it covers
only these two points, starting and
stopping. He should have in mind to
so operate his engine that it would
show the least possible wear and that
It would give the maximum power for
the minimum amount of fuel con-
sumed.
The relative importance Of these
two items will depend somewhat upon
circumstances, but in all cases the OPP
orator must bear in mind that the cost
of the power produced is made up of
the wear and tear Of the engine, and
the fuel used plus fixed charges of
wages, interest on investment, etc.
In this article we will consider only
the influence of the proper mixture OF
air and gasoline upon the amount Of
fuel used.
Few people realize the importance
of supplying air and gasoline in a def
mite proportion to the gasoline engine.
We ordinarily think of a gasoline en-
CINE as using gasoline as fuel. not con.
sidering the air, but the latter Is quite
as essential as the former. A mix
ture of gasoline vapor and air will
explode or burn II the two are present
In the proper proportion: but a mix
ture too rich in gasoline will not ex-
plode nor will one which is very weak
or lean. The function Of the carbur-
ter, or mixer, on the engine is to mix
the air and gasoline in the proper pro-
portion; but every carburter is ad-
Unstable, and it becomes the duty Of
the operator to adjust the amount of
gasolj. that the carburter feeds the
engine, the air remaining constant as
q rule.
It takes but q small amount of ex-
perimenting on the part Of the opera
tor to discover that a very rich mix
ture Of a very lean one will not ex-
plode and that the engine will stop ii
supplied with q very large air or q
very small amount Of gasoline. We
must not imagine, however, that be-
cause an engine keeps on running that
1t is getting the proper mixture.
There is quite q range from the rich
est to the leanest mixture that an en-.
CINE will run at, and the operator
must find the point at which he will
get the maximum power for the
amount Of fuel used.
AS q means Of detecting whether our
mixture is very rich or weak, we find
that black smoke at the exhaust Is
caused by too much gasoline and that
sharp explosions In the exhaust pipe
by q very lean or weak mixture. We
also find that the lean mixture Will
cause the engine to miss explosions
even though It may keep on running.
It Is impossible to give q very def.
mite suggestion az. to the amount Of
gasoline to supply, but we find that
the average engine will develop its.
greatest power when the gasoline sup
ply Is just q trihe less than that.
which viii cause black smoke at the
exhaust. The most economical mix.
turs ID. however,, not quite as rich @