35640 Avenue F, Yucaipa, California 92399.
I wish to add a few remarks to the excellent article in the
Sept.-Oct. issue of GEM as submitted by Mr. Stambaugh, re Oil pull
Tune-up. This is based upon my experience with my model M 20-35
fine old Rumely.
In this particular case (not Case), the water tank had long
since become rusted away and discarded before I acquired the prize
from the junkyard in Spokane, Washington. Also, since the running
service which 1 expected from this engine was comparatively light,
and the availability of distillate or kerosene was scarce, to say
nothing of the higher price compared with gasoline, and since it
was usual to start on gasoline anyway, I decided to operate on
gasoline straight.
Of course, the first thing which thus became apparent was a very
bad ping during ignition in the cylinders, with the original
35-degree running advance, with no water for cushioning. However, I
did some experimenting and found that with leaded types of gasoline
the engine would operate like any straight gasoline stationary or
tractor if the spark was set for about ten degrees running advance.
This put it in the category of the old 20-40 Case gas tractors and
others of that vintage; that is, slow running engines. Now, as
mentioned above, I would not expect to obtain the full power under
such conditions, as compared with a good kerosene-water mixture
which would result in an expansion much like a steam engine at
short cutoff. But it does allow of easy convenient startup and
handling, and at low cost. While Mr. Stambaugh did not call out the
particular allowances to be employed between cold and hot valve
clearance settings, it is presumed that the valve settings as given
for cold might be rechecked after the engine had become well warmed
up. This would prevent any hold-open and consequent burning of
valves and loss of power.
Hornsby Ackroyd, No. 313 Crued oil vaporizing 16′ diameter x
20′ stroke. Has crosshead on piston rod. 7?’ x 6′
flywheels and 5′ diameter crankshaft. Weight 7? tons. Paul is
standing near this engine.
Again, speaking of the; reliability of starting one of these old
timers in the coldest weather, do we readers recall that
‘downdraft’ carburetion .(mixing) was employed on these old
timers long before the automobile industry fell wise to its
advantages? This makes for easiest starting in cold weather because
the mixing bowl is mounted directly on the cylinder head and thus
any priming fuel is effectively dumped right into the cylinders
with the intake air. I wonder if some of the automotive design
engineers may have grown up with an old gas tractor? A minimum of
intake manifold length thus offers least opportunity for fuel
condensation in a cold engine. How well the old opposed motors
would have responded had mixing bowls been mounted on each pair of
cylinder heads rather than one bowl being connected with all
cylinders by means of the exceedingly long intake manifolding!
Again, my sincere compliments to you wonderful folks for the
superb manner in which you continue to publish both IMA and
GEM.
