"Now we'll see how good you
are at burning carbon," remarked Joe Clark to his partner, Gus Wilson, as
the latter stood back and surveyed the portable carbon burning outfit he had
"Humph!" Gus growled.
"If everything else around the Model Garage gets done as well as the carbon
burning I do, we'll never have any kicks."
"Guess I'm going to be the
first customer for the new outfit," called out Arthur Watford as his car
rolled up behind the two garage men.
"Howdy, Watford. You
want some carbon burning done, I take it," said Gus. "All right, I'll
leave your motor running a minute. I want to see how bad it is."
"Pretty well clogged up, I
should judge," he continued after speeding up and slowing down Watford's
motor several times, meanwhile listening carefully. "One cylinder
seems to be a bit worse than the others, but that's nothing unusual.
How does she pull on the hills?"
"Not so good," Watford
replied. "It doesn't miss any explosions, but it knocks like the
dickens if I open the throttle very much, and it hasn't nearly so much power
as it should."
"Compression is fine, too,"
observed Gus as he turned the motor over with the crank. "Well, let's
Gus first placed a fire
extinguisher in a convenient place on the running board and then proceeded
to remove all the spark plugs and the plate that covered the valve stems.
"You're not aiming to burn
up the old bus, I hope," laughed Watford.
"Don't worry," advised Gus.
"I haven't had to use the fire extinguisher yet, but you never can tell.
An ounce of prevention is worth a lot more than a burned-up auto, so I never
take a chance."
"Watch that intake valve
and tell me when it starts to close," he instructed, pointing to the intake
valve on the first cylinder as he slowly cranked the motor. Watford
called a second later.
"All right," said Gus,
"come around here and turn the motor over real slow until I tell you to
Gus inserted a piece of
stiff wire in the spark plug hole far enough to touch the top of the piston,
pulling it out gradually as the piston traveled upward. When it
reached the top he signaled Watford to stop turning the crank.
"Now for the burning," said
Gus as he turned on the oxygen and threw a lighted match into the spark plug
hole, following it with the end of the copper pipe from which a stream of
oxygen was flowing.
A roaring flame immediately
shot out of the spark plug hole.
"That's just the oil
burning up," Gus explained. "As soon as that is all gone the carbon
will take fire. See the sparks coming out now. That's the
Gus kept the end of the
pipe moving so that the gas was sent to every part of the cylinder head and
the top of the piston. The quantity of sparks grew less, and finally
the glow went out.
"That cylinder is as clean
as you can get it by burning," observed Gus as he went around to the front
of the car again and turned the crank exactly one third of a revolution.
"You don't have to use the wire to find top center for the other pistons
after the first. All you do with a six cylinder motor is turn it over
a third of a turn and then burn the next cylinder according to the firing
order. See those numbers molded into the side of the crank case?
No. 5 comes after No. 1, so we burn No. 5 next."
"Four-cylinder motors can
be done in the same way, only you turn the crank halfway around each time
and with eight cylinders you give it a quarter turn."
"How do you know the valves
will be shut?" questioned Watford.
"That's easy, replied Gus.
"The valves are always closed when the cylinder is ready to fire, so you
don't get it to the firing point you are bound to be right."
"Seems to me I've heard
it's not a good idea to burn out the carbon in a motor that has a detachable
head," Watford said. "They claim it is likely to injure the gasket.
How about it?"
"It won't be damaged if you
are careful and don't try to do the job too quick, all the time. I
never had any trouble that way."
After Gus had finished
burning all six cylinders, he replaced the spark plugs, connected the wires
to them, and started the motor. It sputtered and ran unevenly for a
few moments. "She'll run smooth as soon as all the loose particles of
carbon have been blown out through the exhaust valves," he explained as Joe
handed Watford his change.
As Watford drove off up the
road Joe noticed another car coming in the opposite direction. "Here's
old man Burdett again," he exclaimed. "I suppose he's got a couple of
complaints in his system as usual."
Joe's prediction was partly
right, for Burdett stopped in front of the Model Garage. But he
didn't register any kicks.
"Somebody told me you were
going to put in a carbon burning outfit – " he began, and then he spotted
the new apparatus. "I see you have it already. It's just loaded
with carbon. Can you fix me up?"
"Sure I can," replied Gus,
"but not by burning out the carbon. From the way that motor is running
there is a whole lot wrong beside too much carbon and it would still run
rotten even if I did give it a burning out."
"Is that so! Growled old
Burdett. "It's the carbon that's making it run rotten, I tell you, and
if you burn that out I'm sure it will be all right."
"But burning the carbon
only cleans out the cylinders," Gus protested. "Your valves are
sticking because there is carbon caked on the stems, and the oxygen doesn't
cure that trouble at all. And if the valves have been sticking for any
length of time they're sure to be pitted bad enough to need regrinding."
"Burning out the carbon is
worthwhile only when the motor is otherwise all right. For your motor,
the best way will be to take off the cylinder head, scrape out the carbon by
hand and grind the valves, paying special attention to getting the caked
carbon off the stems."
"Yes, and you'll want about
a million dollars to do that job," snapped Burdett. "I guess I'll do
"Why not?" Gus suggested
amiably. "It isn't very difficult even if it does take time and gets
your hands dirty. You don't even need any special tools except a valve
lifter and some grinding compound. And we have a valve lifter in stock
that will only cost you the price of burning two cylinders."
The idea seemed to appeal
to Burdett, for he went into the office with Joe and came back in a few
minutes with a package under his arm.
"How do I get started?" he
"First, drain the
radiator," Gus told him. "Then take off the top hose connection, the
one that goes to the cylinder head. Your motor has the valves at the
side, and that means that both the intake and exhaust manifolds are bolted
to the cylinder block. If you had an overhead valve motor you would
have to take them off too."
"After that get out the
wrenches and loosen up all the cylinder head bolts about two or three turns.
Then step on the self-starter and let the motor turn over a few times.
The compression will loosen up the head if it happens to be stuck tight.
Get busy with the wrench again and take out all the spark plugs and the
cylinder-head bolts and then lift the cylinder head off."
"Isn't it pretty heavy?"
"You can lift it easily
enough," replied Gus. "You see it is all hollowed out for the cooling
water so it's not nearly so heavy as it looks."
"Scrape all the carbon out
of the cylinder head with an old screwdriver. Then scrape off the top
of the pistons, one after the other, and be sure to cover up the bolt holes
and the cylinders you are not working on to keep the scrapings from clogging
"You get the valves out
this way," Gus continued as he took off the plate on the side of the motor
and showed Burdett how to use the valve lifter. "Watch out you don't
lose the pins and be extra careful not to mix up the valves. They all
look alike, but the exhaust valves on this car and on some other makes are
made of tougher material than the intake valves, and if you get them
switched around the motor will run right for about a week and then the
misplaced valves start to warp and you will have to do the job of grinding
them all over again."
"Don't use too much
grinding compound and don't press too hard on the valves and you will find
that the water-floated grinding compound Joe sold you will do a fine job in
no time at all. Be sure to get all the caking off the valve stems and
polish them as bright as possible."
"Huh!" Grunted Joe after he
had gone. "I suppose he thinks we guarantee the job just because you
gave him a few instructions. Why didn't you argue him into letting you
"Don't worry," Gus grinned.
"Burdett hates to get his hands dirty, and after he has spent about a week
trying to get the dirt off 'em from that job, he'll come around the next
time and have us do it!"