Gus Wilson always insisted that hot weather didn't
bother him, but Joe Clark, his partner in the Model Garage, knew better.
Whenever the mercury began to flirt with the top of the thermometer, Gus
started grumbling.
"I never saw such a lot of picayune jobs!" the old
auto mechanic growled as he mopped the perspiration from his brow with a
handful of waste. "I'm sick of cleaning the muck out of carburetors,
changing spark plugs, putting new bulbs in headlights and going out on
trouble calls to find out that some bonehead's motor doesn't 'mote' because
he forgot to fill the gas tank!
"See what that bird outside is honking his horn for,
Joe. I suppose it's something important - needs a new hub cap, or
something."
"Better go out and have a look at that car, Gus," said
Joe a few minutes later.
"He says it overheats, and it sure is hot enough to
fry eggs on: but I can't seem to locate the trouble."
"Probably needs a new fan belt," Gus muttered
disgustedly as he started for the door.
But Gus's bored expression rapidly changed to one of
interest as he progressed with the inspection of the motor in the customer's
car. The motor was overheating - that was quite obvious.
Although it had been stopped for several minutes, heat
waves still were rising from it in a shimmering cloud and there was a smell
of scorched paint mingled with the odor of hot, oily metal. Yet the
fan belt was in place and the radiator appeared to be full of water.
"When did you first notice any trouble, Mr.--?"
inquired Gus.
"Name's Hardy - I sell sewing machines," replied the
car owner. "If it was a sewing machine that wasn't working right -
bobbin gone wrong, shuttle on the blink or something like that - I'd know
what to do, but this outfit sure has my goat! It'd do fine as a cook
stove but it's a total loss as an automobile. I bought it second hand
last month and it's been broiling my feet ever since."
"Start it again and let me listen to it," Gus
requested.
Hardy stepped on the self-starter and the motor
started at once. It ran smoothly without a sign of a miss. Gus
opened the filter cap on the radiator and squinted down the hole.
"Speed her up a bit," he said.
Apparently satisfied with what he saw, Gus closed the
radiator cap. Then, after the motor had been running for several
minutes, he felt all over the front of the radiator and proceeded to place
his hand on various parts of the cylinder block and cylinder head.
"I suppose it steams on all the long hills," Gus
observed.
"Yeah, it sure does," replied Hardy.
"Blows off steam like a teakettle on a rampage by the
time it gets to the top. I have to fill the radiator with water every
time I get gasoline."
"There's a hill right near here," Gus suggested.
"I'd like to see how it acts,"
"Hop in," said Hardy, "you won't get cold feet in this
car at any rate."
But Gus had forgotten the heat for the time being.
He was too much absorbed in finding the cause of the over-heating, and so he
carefully observed the way in which the car accelerated and appeared to be
listening intently for queer noises. They started up the hill in good
style. About half way up the water began to boil, and a few hundred
feet further on the motor developed a hollow ringing knock that seemed to
come from only one cylinder.
"Better stop and let it cool off a bit," Gus advised
when they reached the top of the hill. "Then we can go back," he
added. "I know what's wrong. It's what the doctors call a
complication of diseases."
"That means a hopping big repair bill," groaned Hardy,
"and I haven't sold a single sewing machine this week. About how much
is it going to set me back?"
"Don't worry," said Gus with a smile.
"You can have a powerful lot of things fixed on an
automobile for a few dollars if they are all little items. And all of
yours are.
"I don't remember ever having run into such a queer
combination," continued Gus. "Not one of the things that are wrong
with this car would amount to anything by itself. But each one has a
tendency to cause overheating, and working together they sure have put the
motor on the bum.
"There's nothing radically wrong with the cooling
system. Barring one particular trouble, it's just a sort of general
let down in operating efficiency. Take the radiator, for instance.
It looks clean enough - if you just glance at it. But if you inspect
it carefully you'll notice that a lot of dirt is caked in the openings.
That dirt has two bad effects. First, it cuts
down the amount of air that the fan can suck through the radiator.
Second, it prevents the air from touching the actual metal surface, and so
keeps the radiator from getting rid of its heat to the air. The fan belt is
slipping because it's too loose, and that still further slows down the air
flow through the radiator. And I think a measurement will show that
the angle of the fan blades is not right. They are set nearly parallel
to the radiator. They should be at a greater angle so as to scoop more
air through at each revolution. Whoever had the car before you must
have bent them that way to make the motor run warmer in cold weather, and
then he forgot to bend them back again in the spring.
"The pump seems to be working all right. When I
looked in the filler opening in the radiator, I could see the water whirling
around, due to the increased speed of the pump when you stepped on the
throttle. And there really isn't much that can happen to the pump,
anyway, as long as it keeps on working at all. But circulating the
water through the radiator and cylinder jackets won't keep the motor from
getting too hot if the radiator is coated with mud on the outside and full
of muck, scale and rust on the inside and the jackets are in the same
condition.
And from the looks of things I'm pretty sure that's
the case with this motor."
"You don't mean to say that a little dirt will make
any car overheat as bad as this one does, do you?" exclaimed Hardy
skeptically.
"Not by itself, perhaps," admitted Gus, "but there are
other things wrong.
Your carburetor is set for a rich mixture.
The spark doesn't advance as far as it should, and I'm
certain that the muffler is choked with carbon. Those three things would be
enough to cause a little overheating on a warm day, even if nothing was
wrong with the cooling system."
"When the motor gets real hot there's a funny knock,"
said Hardy. "Has that got anything to do with the cooling system?"
"Probably," replied Gus. "Maybe the dirt in the
water jacket has collected over one cylinder to such an extent that the head
overheats at that point. Or perhaps some of the holes between the
cylinder jacket and the head jacket are stopped up. That would keep
the water from circulating over that particular head and it would naturally
get hotter than the others. We'll see what happens when I flush it
out."
By this time they had arrived back at the garage and
Gus got busy at once.
"It'll probably take at least an hour, Mr. Hardy; do
want to wait?" Gus inquired as he started to drain the radiator
preparatory to flushing it out with a strong solution of lye.
"Sure I'll wait," replied Hardy, fanning himself with
his hat. "Nobody wants to buy sewing machines in this weather, anyway.
I'll get me a nice cold bottle of soda pop and maybe
take a snooze under that tree while you work!"
After the water was all out of the radiator, Gus
filled it with the lye solution and ran the motor at a rapid rate until it
had warmed up again. Then with the motor still running, he opened the
drain petcock at the bottom of the radiator, stuck the water hose in the
filler opening, and turned on the water fast enough to make up for the
amount that ran out at the drain cock. At the end of about fifteen
minutes of this treatment, the water that issued from the bottom was
perfectly clear, indicating that all the dirt that had been in the cooing
system was out, or at least as much of it as could be removed by that
particular method of cleaning.
"I hope it got the dirt out of that clogged-up
cylinder head," Gus muttered to himself. "If it didn't, I'll have to
take the cylinder head off."
With the inside of the system cleaned out, Gus set to
work to clean the crusted mud out of the radiator fins. He put the
nozzle on the hose and set it to squirt a solid stream about the size of a
pencil. Then he shot the stream through the openings in the radiator
from the inside so that the water and the dirt it dislodged would be thrown
out at the front.
Bending the fan blades so that they would pull more
air took only a moment, and then Gus examined the fan belt.
"I could tighten it up and it would run all right.
I suppose," he thought.
"Still, it's worn to a frazzle, and it'll soon give
out anyway. Guess I'll put in a new one."
Gus tackled the ignition next. He found that one of
the coated levers had become bent so much that it didn't push the timer case
around far enough when the spark was advanced.
"A chimney sweep would feel right at home on this
job!" Gus exclaimed as he started cleaning out the muffler. But a
stiff wire brush enabled him to finish the disagreeable work in a short
time.
"All ready for a test, Mr. Hardy," Gus called a few
minutes later to the sewing machine salesman who was snoring peacefully
under the tree.
Once more Gus climbed in behind the wheel and they
headed for the test hill.
This time the car arrived at the top without any sign
of boiling. The lye evidently had done its work and opened up the
clogged passages in the cylinder head, because the knock also had
disappeared.
"There's one point you ought to remember, Mr. Hardy,"
Gus suggested.
"The motor got up this hill without boiling, but if
the hill had been twice as long it probably would have boiled if I had kept
it in high gear.
When you get on a steep, long hill in hot weather,
especially when you are driving with the wind, you'll find that the motor
will stay a whole lot cooler if you shift to second instead of trying to go
all the way up in high.
There's two reasons why the motor cools better in
second speed under such conditions. One is that the motor turns over
faster and the fan consequently pulls more air through the radiator.
The other is that the pump circulates more water through the cylinder
jackets, and carries off the heat much more quickly.
"I thought I heard you say you were tired of picayune
jobs," grinned Joe Clark to Gus after Hardy had departed.
"Humph!" growled Gus. "My idea of a picayune job
is one that anybody can do. The ones on that car had you stumped!"
END
